How about it? Experiments of the third kind , take 999999.

[Jan Panteltje]

This is an idea for an experiment I may or may not do.
The background:
There have been reported seasonal variations in radioactive decay in the past.

Now If I took a simple tritium light, and a good quality photo-diode,
put both in a light proof box,
and logged that with a 10 bit PIC ADC with a decent Vref for say a year
to FLASH, say 1 sample / hour, run the whole thing of some battery.
10 bits per hour makes 87660 bits per year, or 10950 bytes per year.
Have the PIC wake up once every hour to save power.

Would the light intensity from a tritium light be [linear] proportional
to the decay of the tritium?
And then next year analyze the result (if any)?

[hamilton]

Will one year be enough time to see any difference ??


Being an unstable isotope with a half-life of about 12.32 years, tritium
loses half its brightness in that period. The more tritium that is
initially placed in the tube, the brighter it is to begin with, and the
longer its useful life. Tritium exit signs usually come in three
brightness levels guaranteed for 10, 15, or 20 year useful life
expectancies.[citation needed] The difference between the signs is how
much tritium the manufacturer installs.


http://en.wikipedia.org/wiki/Tritium_illumination

[John Larkin]

Probably.

>And then next year analyze the result (if any)?

You'd really have to run it for several years to make sure there's a
pattern. And keep the temperature constant, and make sure there are no
other seasonal effects. Particle counting would make better data than
light measurement.

How about getting a few hundred people to do this worldwide? A USB
dongle, maybe.

But the decay-rate variations seen so far happen in a few isotopes,
not tritium as far as I know.

Interesting: what does the optical noise look like from a tritium
light? It will certainly have shot noise, but are single decays
detectable? A betalight and a PMT would tell.




--

John Larkin, President Highland Technology Inc
www.highlandtechnology.com jlarkin at highlandtechnology dot com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators
Custom timing and laser controllers
Photonics and fiberoptic TTL data links
VME analog, thermocouple, LVDT, synchro, tachometer
Multichannel arbitrary waveform generators

[Martin Brown]

Unless you are very very careful all you will succeed in measuring is
the thermal drift in your opamps and photosensors as they vary with
ambient lab temperature. Most of the claims of seasonal variation look
like they will fail on variants of this sort of systematic error.

http://physicsworld.com/cws/article/news/36108

It is just about possible that half lives of certain nuclear decay
reactions could be influenced by variations in neutrino flux, but then
you would also expect to see a signal in changed half lives when large
pulses of supernova neutrinos transit the Earth as well and not just
from the relatively small variation in solar neutrino flux.

Also sling shot launches that have gone very close to the sun do not
show any noticeable variation in radiothermal generator output.

--
Regards,
Martin Brown

[George Herold]

On Mar 20, 11:40 am, John Larkin

<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
> On Tue, 20 Mar 2012 12:38:32 GMT, Jan Panteltje
>

Oh that might be fun. Can you get a tritium light in the US? You
should get a bunch of phosphor photons for each beta decay. But
what's the 'lifetime' of an excited phosphor? If it takes too long
for the phosphor to decay that will smear out any spikes.

George H.
>
> --
>
> John Larkin, President       Highland Technology Incwww.highlandtechnology.com  jlarkin at highlandtechnology dot com

[John Larkin]

Only for gunsights! And exit lights, maybe.

I ordered a bunch of the key-ring types on ebay, shipped from Hong
Kong as I recall. I put a couple on the tops of the bedposts in our
cabin, where it's really dark at night, so we wouldn't crash into them
in the dark.

You
>should get a bunch of phosphor photons for each beta decay. But
>what's the 'lifetime' of an excited phosphor? If it takes too long
>for the phosphor to decay that will smear out any spikes.

True.

Light from an old radium clock hand makes beautiful PMT pulses.

I find it interesting that billions are being spent on big-science
stuff like CERN, when a little cheap research on possible solar
effects on isotope decay could lead to really revolutionary physics.


--

John Larkin, President
Highland Technology, Inc

jlarkin at highlandtechnology dot com

http://www.highlandtechnology.com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators

Custom laser controllers

Photonics and fiberoptic TTL data links

VME thermocouple, LVDT, synchro acquisition and simulation

[Sam Wormley]

Please do the experiment and keep all the electronics at a constant
temperature. Thanks!

[Martin Brown]

On 20/03/2012 17:33, John Larkin wrote:
> On Tue, 20 Mar 2012 10:10:04 -0700 (PDT), George Herold
> <ghe...@teachspin.com> wrote:
>
>> On Mar 20, 11:40 am, John Larkin

>>> Interesting: what does the optical noise look like from a tritium
>>> light? It will certainly have shot noise, but are single decays
>>> detectable? A betalight and a PMT would tell.
>>
>> Oh that might be fun. Can you get a tritium light in the US?
>
> Only for gunsights! And exit lights, maybe.

And the illuminated plastic emergency signs for use in aircraft.

>
> I ordered a bunch of the key-ring types on ebay, shipped from Hong
> Kong as I recall. I put a couple on the tops of the bedposts in our
> cabin, where it's really dark at night, so we wouldn't crash into them
> in the dark.

In the early days we made a fair number of DIY tritium watches using
fishing floats. It had the side effect of making the watch susceptable
to a reset by flash gun but apart from that worked well enough.

> You
>> should get a bunch of phosphor photons for each beta decay. But
>> what's the 'lifetime' of an excited phosphor? If it takes too long
>> for the phosphor to decay that will smear out any spikes.
>
> True.
>
> Light from an old radium clock hand makes beautiful PMT pulses.

And quite a good source for a DIY cloud chamber too. The alpha particles
and betas give quite different tracks.

>
> I find it interesting that billions are being spent on big-science
> stuff like CERN, when a little cheap research on possible solar
> effects on isotope decay could lead to really revolutionary physics.

The amount being spent on this is about in proportion to the likelihood
that it will yield anything really interesting. Various chemical and
physical tricks are known to alter half lives of a handful of elements
but the claims so far of solar influence on radioactive half lives do
not look like much more that systematic noise. See for example:

http://arxiv.org/ftp/arxiv/papers/0808/0808.3156.pdf

If they get a decent signal for a supernova neutrino flash going past
then that would be interesting. For the moment it remains a curiosity
and they don't seem to be able to make up their mind whether the decay
reactions are catalysed by neutrinos or inhibited. The seasonal
variation they claim to observe lags the Earths orbital position and is
almost exactly correlated with external temperature which I find highly
suspicious. YMMV

http://arxiv.org/pdf/0808.3283v1.pdf

Most of what has been written about it to date is from Creation Science
kookdom and bears absolutely no relation to reality whatsoever.

--
Regards,
Martin Brown

[Jan Panteltje]

On a sunny day (Tue, 20 Mar 2012 08:54:54 -0600) it happened hamilton
<hami...@nothere.com> wrote in <jka5o6$b0i$1...@dont-email.me>:

>On 3/20/2012 6:38 AM, Jan Panteltje wrote:
>> This is an idea for an experiment I may or may not do.
>> The background:
>> There have been reported seasonal variations in radioactive decay in the past.
>>
>> Now If I took a simple tritium light, and a good quality photo-diode,
>> put both in a light proof box,
>> and logged that with a 10 bit PIC ADC with a decent Vref for say a year
>> to FLASH, say 1 sample / hour, run the whole thing of some battery.
>> 10 bits per hour makes 87660 bits per year, or 10950 bytes per year.
>> Have the PIC wake up once every hour to save power.
>>
>> Would the light intensity from a tritium light be [linear] proportional
>> to the decay of the tritium?
>> And then next year analyze the result (if any)?
>
>Will one year be enough time to see any difference ??

For 'seasonal' changes it should be.
One can substract a gradual decrease due to half life, that should be linear.

[Jan Panteltje]

On a sunny day (Tue, 20 Mar 2012 08:40:05 -0700) it happened John Larkin
<jjla...@highNOTlandTHIStechnologyPART.com> wrote in
<ji8hm75mbep2rl69q...@4ax.com>:

>On Tue, 20 Mar 2012 12:38:32 GMT, Jan Panteltje
><pNaonSt...@yahoo.com> wrote:
>
>>This is an idea for an experiment I may or may not do.
>>The background:
>>There have been reported seasonal variations in radioactive decay in the past.
>>
>>Now If I took a simple tritium light, and a good quality photo-diode,
>>put both in a light proof box,
>>and logged that with a 10 bit PIC ADC with a decent Vref for say a year
>>to FLASH, say 1 sample / hour, run the whole thing of some battery.
>>10 bits per hour makes 87660 bits per year, or 10950 bytes per year.
>>Have the PIC wake up once every hour to save power.
>>
>>Would the light intensity from a tritium light be [linear] proportional
>>to the decay of the tritium?
>
>Probably.
>
>>And then next year analyze the result (if any)?
>
>You'd really have to run it for several years to make sure there's a
>pattern. And keep the temperature constant, and make sure there are no
>other seasonal effects. Particle counting would make better data than
>light measurement.

Yes several years the same pattern would give more support to any data indicating seasonal changes.
But even in one year one should see a cyclic event if it exists.

>How about getting a few hundred people to do this worldwide? A USB
>dongle, maybe.

Cool idea.

>But the decay-rate variations seen so far happen in a few isotopes,
>not tritium as far as I know.

Well, at least I can then claim an upper limit.

>Interesting: what does the optical noise look like from a tritium
>light? It will certainly have shot noise, but are single decays
>detectable? A betalight and a PMT would tell.

I taped one to the small Russian PMT I have,
and had to lower the PMT voltage to about 100V to get a reasonable low anode current.
I can make a stable PMT voltage and amplifier, but the PMT will change,
and is very sensitive to even earth magnetic field or any
other magnet in the vicinity, plus the whole setup is expensive.
A PMT is too sensitive for this, basically.

So today, for lack of a real photo-diode, I took a Nichia green LED,
and taped it to the tritium light tube, put it in a box,
and made a small test circuit to get some idea of the 'signal' amplitude.

Both in the PMT case and the LED case I scoped the output to, and did
not see any 'individual' flashes.
There are probably too many activations or the phosphor persistence is too long.
I did get speckles last year when I made a movie of the tritium light
with the Canon A470 camera:
http://panteltje.com/pub/tritium_light_movie_mvi_3243.avi
The other thing that surprise me, is that even a very strong magnet next
to the tritium light does not seem to change the distribution of the light
over the tube, or the intensity in any way.
All good things for a circuit with a small PIC and photo diode.

---------------------------------------- +5 V
| |
[ ] 10k [ ] 1k
| |
|| | Chinese multimeter
|| --- green 2 mA range
|| \ / \ LED ---------|
|| --- | |
|| | |/ |
-------------| NPN |
Tritium |\/ |
light tube | |/
------| NPN
|\/
|
///

2 x BC547B

The resistors are to protect the parts...
I get only about 2 uA with this setup, 0 without the tritium light,
over range on daylight,
so green LED is not what I should use.
Will need a good opamp and real photo-diode.
Any idea for a sensitive photo diode that does not cost a zillion?

[Jan Panteltje]

On a sunny day (Tue, 20 Mar 2012 13:19:12 -0500) it happened Sam Wormley
<swor...@gmail.com> wrote in <K_Cdna4DPsC9V_XS...@mchsi.com>:

Yes Sam, will make sure there is no drift from the electronics.

[John Larkin]

On Tue, 20 Mar 2012 18:27:40 GMT, Jan Panteltje

Look at the Osram SFH-series parts.

Osram makes really nice stuff.


--

John Larkin, President
Highland Technology, Inc

jlarkin at highlandtechnology dot com

http://www.highlandtechnology.com

Precision electronic instrumentation
Picosecond-resolution Digital Delay and Pulse generators

Custom laser controllers

Photonics and fiberoptic TTL data links

[Adrian Jansen]

IF there is a variation in half-life caused by seasonal changes in
radiation ( and its a big IF, IMHO ), then surely it would be easier to
detect by gating a strong radiation source on and off locally, and
detecting the half-life change in sync. Of course you have to choose
the radiation source.... But at least you could reasonably eliminate
other external influences, and get a result in a few hours, rather than
years.

--
Regards,

Adrian Jansen adrianjansen at internode dot on dot net
Note reply address is invalid, convert address above to machine form.

[George Herold]

On Mar 20, 2:36 pm, Jan Panteltje <pNaonStpealm...@yahoo.com> wrote:
> On a sunny day (Tue, 20 Mar 2012 13:19:12 -0500) it happened Sam Wormley

> <sworml...@gmail.com> wrote in <K_Cdna4DPsC9V_XSnZ2dnUVZ_sedn...@mchsi.com>:

>
>
>
>
>
> >On 3/20/12 7:38 AM, Jan Panteltje wrote:
> >> This is an idea for an experiment I may or may not do.
> >> The background:
> >> There have been reported seasonal variations in radioactive decay in the past.
>
> >> Now If I took a simple tritium light, and a good quality photo-diode,
> >> put both in a light proof box,
> >> and logged that with a 10 bit PIC ADC with a decent Vref for say a year
> >> to FLASH, say 1 sample / hour, run the whole thing of some battery.
> >> 10 bits per hour makes 87660 bits per year, or 10950 bytes per year.
> >> Have the PIC wake up once every hour to save power.
>
> >> Would the light intensity from a tritium light be [linear] proportional
> >> to the decay of the tritium?
> >> And then next year analyze the result (if any)?
>
> >   Please do the experiment and keep all the electronics at a constant
> >   temperature. Thanks!
>

> Yes Sam, will make sure there is no drift from the electronics.- Hide quoted text -
>
> - Show quoted text -

Hi Jan, I'm enjoying your thread.... Walking around in this 'amazing'
70+ spring day!
You'll want to keep the source - detector geometry thermally stable
too.

The problem with looking for a signal, that might be zero, is there
are a lot of ways to be fooled.

George H.

[George Herold]

Yeah I gotta agree... get a big signal first!

Then you can run some statictics,/ statistics,*
on it.

George H.

*(ahh I never can get that word right.)

[Robert Baer]

Decay is exponential - remember? Half-Life. If half life is a year,
then after one hear half has decayed, the next year half of that has
decayed, etc so look at it as an RC decay with time constant of a year -
and in 5 years (5*tc) it would be essentially completely decayed.
So...
That sampled light should show that same RC type drop (linear
relationship between decay, emission, and light).

[be...@iwaynet.net]

Obviously this experiment is totally hosed. Wormley hints at the
problems but as usual he can't understand what's wrong either.

Look. You are starting with a digital source! So why convert to an
averaged analog signal to examine the phenomenon? As Uncle Al used to
say: Stooopid!

He's the REAL experiment: Start with a radioactive source. ANY you have
a reason to study will do. Then using a proper nuclear detector and
multichannel analyzer (we all have a couple of those on our workbenches,
right? I know I do) to act as a filter for the events we want to see. We
set up our conditions whatever we want them to be and start recording
radioactive decay events. The data will consist of the number of an
event and the exact time it occured (UTC calibrated against proper
sources, best with rubidium oscillator. We've all got one of those
handy, right? I know I do. They are SO cool!) Then you take data.

If you want you can vary the conditions of the source to see if they
have an effect. And then you analyze the data DIGITALLY to try to find
anomalies, half-life, rate changes etc. People have done this (no
surprise) and small variations seem to have been observed in certain
conditions. But they are small enough that they give no decent hints as
to what exactly is the mechanism that triggers radioactive decay.

Just to tweak you a bit let's do a thought experiment. Suppose for
example you discovered some kind of "ray" that when you shined it on the
radioactive source it's decay rate greatly increased and hence its
half-life greatly decreased. Think of how cool this would be for getting
rid of radioactive waste! You'd have this cave full of vile radioactive
waste down there in Alabama (or other useless region) where they store
the crap. You bring in the "waste decay ray" and suddenly all that
radioactive crap greatly increases it's radiation output. But since it's
all deep in a cave anyway, it doesn't matter. And then in a fraction of
the time you'd normally have to wait for the waste to be safe, suddenly
it's all spent and you can truck in another load to purify. Neat, eh?

All we need is that discovery of the radioactive control ray from you!

[Robert Baer]

BUT!!!
There ARE ways to alter (certain) radioactivity. Many experimenters
have accidentally stumbled into the way/ways, for over 30 years now.
It is only "recently" (Pons and Fleischmann) that some of the methods
have been brought to public light.
Electronics in the form of fields have been used for ages to enhance
nuclear interaction of one form or another,viz: cyclotrons, linear
accelerators, magnetic pinch plasma "bottles", torus shaped containers,
etc; even inside-out electron tubes.
So..the "radioactive control ray" could well be a linear accelerator.

[Jeroen Belleman]

Not linear. Exponential.

Jeroen Belleman

[Jan Panteltje]

On a sunny day (Wed, 21 Mar 2012 08:23:10 +1000) it happened Adrian Jansen
<adr...@qq.vv.net> wrote in
<4f690360$0$1585$c3e8da3$7649...@news.astraweb.com>:

>IF there is a variation in half-life caused by seasonal changes in
>radiation ( and its a big IF, IMHO ), then surely it would be easier to
>detect by gating a strong radiation source on and off locally, and
>detecting the half-life change in sync. Of course you have to choose
>the radiation source.... But at least you could reasonably eliminate
>other external influences, and get a result in a few hours, rather than
>years.

I already tried to find count per minute changes for several radiation sources
exposed to anti-neutrinos from the tritium light [2], with the tritium light
close and far away (should be third power no?).
Within my measurement accuracy, and even over 8 hour runs,
using plastic scintillator and PMT setup, I see no clear changes in cpm
for radium, thorium, normal background, uranium, and a few others that
I am not allowed to mention here.
Have not tried kryptonite yet.

Anyways that sucks in many ways, as statistically speaking the uncertainty
of my measurements is very high.
Sometimes in one run you see a change, and the next one it is not there,
How many million times does one has to run to be *sure*?

So I got fed up with that, Einstein once did say:
"An idiot is somebody who keeps repeating the same experiment over and over again expecting a different result [1]."

So to let the electronics do the experiment, and look after a year at the data
seems a better way to once and for all settle the issue (if solar neutrinos or something else affects radioactive decay).
And cheap, all parts are in the junk box.



[1] He obviously never used a MS windows computah.
[2] The tritium beta decay, if I am informed correctly, produces an anti-neutrino that
leaves the glass tube. Flux wont be very high, so...

[Jan Panteltje]

On a sunny day (Tue, 20 Mar 2012 18:59:43 -0800) it happened Robert Baer
<rober...@localnet.com> wrote in
<u_ydnVqssLKLq_TS...@posted.localnet>:

Yep,
and if it has superimposed something that goes up and down with the seasons..

[Jan Panteltje]

On a sunny day (Tue, 20 Mar 2012 22:33:24 -0400) it happened
"BJA...@teranews.com" <be...@iwaynet.net> wrote in
<G5bar.30632$M%7.1...@newsfe10.iad>:

>On 3/20/2012 2:19 PM, Sam Wormley wrote:
>> On 3/20/12 7:38 AM, Jan Panteltje wrote:
>
>>> Now If I took a simple tritium light, and a good quality photo-diode,
>>> put both in a light proof box,
>>> and logged that with a 10 bit PIC ADC with a decent Vref for say a year
>>> to FLASH, say 1 sample / hour, run the whole thing of some battery.
>>> 10 bits per hour makes 87660 bits per year, or 10950 bytes per year.
>>> Have the PIC wake up once every hour to save power.
>>>
>>> Would the light intensity from a tritium light be [linear] proportional
>>> to the decay of the tritium?
>>> And then next year analyze the result (if any)?
>
>> Please do the experiment and keep all the electronics at a constant
>> temperature. Thanks!
>
>Obviously this experiment is totally hosed. Wormley hints at the
>problems but as usual he can't understand what's wrong either.
>
>Look. You are starting with a digital source! So why convert to an
>averaged analog signal to examine the phenomenon? As Uncle Al used to
>say: Stooopid!
>
>He's the REAL experiment: Start with a radioactive source. ANY you have
>a reason to study will do. Then using a proper nuclear detector and
>multichannel analyzer (we all have a couple of those on our workbenches,
>right? I know I do)

I have those, what's you problem? Brain damage?
- Uncle Al[l] - you must be kidding, his EOTVOS, his artificial diamond factory,
his language, if you are a fan of him only he can help you.
LOL

To quote Al :
"Uncle Al only needs one more valve to have his artificial diamond setup working."
That was 10 years ago.
After that the left sci.physics in shame after he had to admit he could not tell 1 from 2 in scientific papers.
I remember the last conversation here in sci.physics,
where he was quizzing how many of the papers of the preprint server were bogus,
and wanted us to read them, I refused with the comment that they probably all were bogus.
That did not match his estimate and play his game, and he left tail between legs.
A fighter stays, I have seen him spamming some forum lately.

And Sam Wormley is our hero, do not criticize him, he is the best copy cat around.

So, in all this where do I stand? I do some experiments sometimes.
And as to your argument, when looking for seasonal changes, why would you care about pulses per second
you are going to integrate over time anyways, so the tritium light does that for you.
And you do not need spectroscopy to get decay info if you use a pure sample, as you know what is in there.
Running your setup for a year a, no break supply, thermostats, your PMTs will age man,
you have no clue.

[Jan Panteltje]

On a sunny day (Wed, 21 Mar 2012 10:26:31 +0100) it happened Jeroen Belleman
<jer...@nospam.please> wrote in <jkc6s5$m7o$1...@speranza.aioe.org>:

>> One can subtract a gradual decrease due to half life, that should be linear.
>>
>
>Not linear. Exponential.
>f
>Jeroen Belleman

You are right.
Half of half of half of half etc

So say half after 1 day,
1/4 after 2 days,
1/8 after 3 days,
etc.
But easy to subtract in the analysis of the data,
I meant not like a seasonal wave.

[Chieftain of the Carpet Crawlers]

On Wed, 21 Mar 2012 10:20:15 GMT, Jan Panteltje
<pNaonSt...@yahoo.com> wrote:

>After that the left sci.physics in shame after he had to admit he could not tell 1 from 2 in scientific papers.

Is this the total retard JanPan trying to dis Uncle Al?

You're an idiot, dumbfuck. He didn't leave sci.physics at all, idiot,
and certainly not ten years ago.

You are about as dumb as it gets, boy. AND you can't even get your
line length right for Usenet posts!

Will you ever stop posting STUPID CRAP into Usenet? You lying piece of
shit!

[TralfamadoranJetPilot]

On Wed, 21 Mar 2012 10:20:15 GMT, Jan Panteltje
<pNaonSt...@yahoo.com> wrote:

>

>So, in all this where do I stand? I do some experiments sometimes.

Essentially, you are a complete and utter retard.

I hope you get irradiated, and mutate a cell or two, and then get your
body taken over by your "passion", one cell at a time, ending in an
excruciatingly painful death.

The most good you would do this group is for us to get a nice photo of
your agonizing death mask.

Then your only accomplishment would be to teach folks what not to do.

Then, you would have some inkling of 'worth'.

[Dennis]

"Jan Panteltje" <pNaonSt...@yahoo.com> wrote in message
news:jkcae0$1l2$1...@news.albasani.net...

> On a sunny day (Wed, 21 Mar 2012 10:26:31 +0100) it happened Jeroen
> Belleman
> <jer...@nospam.please> wrote in <jkc6s5$m7o$1...@speranza.aioe.org>:
>
>>> One can subtract a gradual decrease due to half life, that should be
>>> linear.
>>>
>>
>>Not linear. Exponential.
>>f
>>Jeroen Belleman
>
> You are right.
> Half of half of half of half etc
>
> So say half after 1 day,
> 1/4 after 2 days,
> 1/8 after 3 days,
> etc.

Thats still linear, IIRC its more of a k.e^(-a.t) ??

[Jan Panteltje]

On a sunny day (Wed, 21 Mar 2012 20:54:29 +0800) it happened "Dennis"
<jon....@ithemorgue.com> wrote in
<7Y6dnTn1sv0VUvTS...@westnet.com.au>:

I tried eating half the cookies every time I was in the kitchen.
Theory being that I would never run out.
Unfortunately due to quantisation the cookies ran out anyways :-)

[Jan Panteltje]

John Larkin, President of Highland Technology, Inc wrote:

>Look at the Osram SFH-series parts.
>
>Osram makes really nice stuff.

I found some, and downloaded the data sheets.
Seems conrad.nl only carries Osram photo diodes.

There is for example the bpx61 with > 50 nA / lx (typical 70)
and the BPW34B with 75 nA / lx.

From my circuit, with a beta of about 330 for each transistor,
and 2 uA output, the LED photo current should be 20 nA.
I raised the voltage to 9 V (battery) and put the cathode of the LED
on a trimpot, so I can adjust the LED reverse voltage.
Above some voltage the LED starts to leak....
Temperature will have an effect too.
Not much current 20 nA, if we assume (just a wild guess) 20 nA / lx
for the LED then it would mean 1 lx from the tritium tube.
The LED has a lens, it is focused on the tube.
Will get some photo diodes later, and also try some other LEDs.

[Jan Panteltje]

On a sunny day (Wed, 21 Mar 2012 13:53:51 GMT) it happened Jan Panteltje
<pNaonSt...@yahoo.com> wrote in <jkcmhl$pso$1...@news.albasani.net>:

>John Larkin, President of Highland Technology, Inc wrote:
>
>>Look at the Osram SFH-series parts.
>>
>>Osram makes really nice stuff.
>
>I found some, and downloaded the data sheets.
>Seems conrad.nl only carries Osram photo diodes.
>
>There is for example the bpx61 with > 50 nA / lx (typical 70)
>and the BPW34B with 75 nA / lx.
>
>From my circuit, with a beta of about 330 for each transistor,
>and 2 uA output, the LED photo current should be 20 nA.

Sorry, 20 pA, because 2 uA / (330 x 330)

>I raised the voltage to 9 V (battery) and put the cathode of the LED
>on a trimpot, so I can adjust the LED reverse voltage.
>Above some voltage the LED starts to leak....
>Temperature will have an effect too.
>Not much current 20 nA, if we assume (just a wild guess) 20 nA / lx

>for the LED then it would mean 1 lx from the tritium tube.

Should be: makes 1/1000 lx.

Really is not much.

[Michael A. Terrell]

Jan Panteltje wrote:
>
> I tried eating half the cookies every time I was in the kitchen.
> Theory being that I would never run out.
> Unfortunately due to quantisation the cookies ran out anyways :-)

You didn't use enough cookies. Start with a couple million, and try
it again.


--
You can't have a sense of humor, if you have no sense.

[Jon Elson]

Jan Panteltje wrote:

> This is an idea for an experiment I may or may not do.
> The background:
> There have been reported seasonal variations in radioactive decay in the
> past.
>

> Now If I took a simple tritium light, and a good quality photo-diode,
> put both in a light proof box,
> and logged that with a 10 bit PIC ADC with a decent Vref for say a year
> to FLASH, say 1 sample / hour, run the whole thing of some battery.
> 10 bits per hour makes 87660 bits per year, or 10950 bytes per year.
> Have the PIC wake up once every hour to save power.
>
> Would the light intensity from a tritium light be [linear] proportional
> to the decay of the tritium?
> And then next year analyze the result (if any)?

You've got phosphor aging, tritium leakage and possibly aging of
other circuit elements. Unless you put in an optical calibration
source that was more stable than the rest of the system, I doubt you
could get much of a result. How about counting Gamma rays, which
will throw out a couple of these effects? You still have to
deal with the Tritium leaking from the capsule, and I have no idea
how you deal with that.

Jon

[Adrian Jansen]

>
> Anyways that sucks in many ways, as statistically speaking the uncertainty
> of my measurements is very high.
> Sometimes in one run you see a change, and the next one it is not there,
> How many million times does one has to run to be *sure*?
>
> So I got fed up with that, Einstein once did say:
> "An idiot is somebody who keeps repeating the same experiment over and over again expecting a different result [1]."
>
> So to let the electronics do the experiment, and look after a year at the data
> seems a better way to once and for all settle the issue (if solar neutrinos or something else affects radioactive decay).
> And cheap, all parts are in the junk box.
>

So if you see a change in one year, do you claim certainty ? What about
the next million ? I think you should read your Einstein quote again.

[Chieftain of the Carpet Crawlers]

On Wed, 21 Mar 2012 20:54:29 +0800, "Dennis" <jon....@ithemorgue.com>
wrote:

>Thats still linear, IIRC its more of a k.e^(-a.t) ??

YOU are dumber than dogshit, boy.

[Robert Baer]

Are not neutrons, neutrinos, and the anti-s all impossible to
directly detect because (mainly) lack of charge?
The only "hope" is if one bashes into something else creating (what
is called) specie - and then one sets up proper detectors and analyzers
to count and measure them and _deduce_ the presence of the original
particle(s).

[Jan Panteltje]

On a sunny day (Wed, 21 Mar 2012 20:56:43 -0800) it happened Robert Baer
<rober...@localnet.com> wrote in
<qfGdnfBhmuOePvfS...@posted.localnet>:

> Are not neutrons, neutrinos, and the anti-s all impossible to
>directly detect because (mainly) lack of charge?
> The only "hope" is if one bashes into something else creating (what
>is called) specie - and then one sets up proper detectors and analyzers
>to count and measure them and _deduce_ the presence of the original
>particle(s).

Yes we live in the electronics world of this age where we do things with charge.
getting hit by a neutral billiard ball does create some effects,
like I mentioned elsewhere neutrino and anti-neutrino detectors
come in many varieties, some just water, where the collisions produce
light flashes that then can be detected with our present day equipment we are so proud of.

[Jan Panteltje]

On a sunny day (Thu, 22 Mar 2012 08:04:50 +1000) it happened Adrian Jansen
<adr...@qq.vv.net> wrote in <4f6a5087$0$11120$c3e...@news.astraweb.com>:

>
>
>>
>> Anyways that sucks in many ways, as statistically speaking the uncertainty
>> of my measurements is very high.
>> Sometimes in one run you see a change, and the next one it is not there,
>> How many million times does one has to run to be *sure*?
>>
>> So I got fed up with that, Einstein once did say:
>> "An idiot is somebody who keeps repeating the same experiment over and over again expecting a different result [1]."
>>
>> So to let the electronics do the experiment, and look after a year at the data
>> seems a better way to once and for all settle the issue (if solar neutrinos or something else affects radioactive decay).
>> And cheap, all parts are in the junk box.
>>
>
>So if you see a change in one year, do you claim certainty ?

In this case I would look for a cyclic effect,
and in such an effect, if it exists, you would, if it is seasonal,
arrive at the same point where you were a year later.
That is after subtracting the decay effect, that can be done because it is known.

>What about the next million ?

There is a Russian paper that finds a connection in the radioactive decay of pl*t*nium to the orientation
of the experiment in the galactic plane.

As spiral arms and galaxies move, feel free to hang around in some forms for a longer experiment.
But me, I want to keep my feet on the earth and just run for one year.

>I think you should read your Einstein quote again.

This is the problem with the physicks today, they take Einstein's formulas and
just extrapolate on those, finding theories of wormholes, singularities, and what not,
running simulations with those equations, and then calling those 'proof', etc.
While Einstein clearly stated that neither are those formulas (of relatitvity) a complete description
of reality, nor should they be used as such (freely translated).

And then there are all his errors, such as photon.
After all Einstein was more a political figure then anything else.
He or his teachings probably set science back a couple of hundred (optimistic), or could
be thousands of years, as brainwashed formula parroting clones are created under the label of 'scientists'
in the schools of today, sort of tape recorders, without any ability to really see.
Like the earth is flat because Einstein did say so[1], and beware those that do not agree or
even look at the horizon and ask why that ship is sinking....
Epicycles.
And you want me to read that AGAIN?
Hey, lets have some fun, I am working on this design.
It is real, the results will be measurable, and it is fun to do.
It is more fun than reading a zillion PhD tissue papers on the preprint server,
and it is in a way a challenge or a puzzle to build this thing as cheap as can be.


[1] He did not say that, but this is just indicate a similarity to that well know case.
[2] Einstein failed to find the 'one stone'.

[Jan Panteltje]

On a sunny day (Wed, 21 Mar 2012 15:31:30 -0500) it happened Jon Elson
<jme...@wustl.edu> wrote in <f-udnSSywKuGpPfS...@giganews.com>:

The advantage of looking for 'cyclic' events with a period time of a year
over other systematic events makes this experiment possible.
Not even interested in absolute values, just in wave patterns.
On top of that I think there is no tritium leakage to speak of from the fused quartz tube.
There is no need for optical calibration.
Just for temperature compensation (dark current compensation) from the photo cell,
and of course will do some oven and fridge tests of the whole setup.
If it is found that the tritium tube needs to be at a fixed temperature,
then, because it is so small, it can be heated with a simple resistor
and measured with a LM335, and the PIC micro controller can keep it at say 45°C.
All old hat electronically.
The only drawback of doing the thermostat thing is that it would need some more power,
and then it would need batteries with a wallwart as backup, or wallwart
with batteries as backup, whatever you picture of the situation is.

I am looking into photo diodes now, have worked out the dark current compensation I think,
now am looking at the amplifier and PIC asm code.

Overall the whole experiment should be in a thermally insulated box with metal shielding I think,
as already in the tests setup EM interference can mess up things.
Jippee!
We are sailing.

[Adrian Jansen]

Your experimental noise means you can never be sure that you have a
'real' cycle after only one period. You need enough cycles to be able
to reduce the noise effect so your measurement certainty is 'enough'.
You can easily calculate how many cycles you need, given the noise and
certainty you require.

A similar problem, and much easier to do, is to measure the atmospheric
pressure change over a 1 day period, and deduce the effect of the solar
(and lunar) gravitational effects on the pressure. Over one day, its
quite difficult, because of all the other atmospheric influences, but
over many days, the noise can be reduced rather well, and the signal is
very easy to see.

[Jan Panteltje]

On a sunny day (Fri, 23 Mar 2012 08:56:16 +1000) it happened Adrian Jansen
<adr...@qq.vv.net> wrote in
<4f6bae17$0$29999$c3e8da3$5496...@news.astraweb.com>:

>
>
>Your experimental noise means you can never be sure that you have a
>'real' cycle after only one period.

That depends on the amplitude of the signal you get now does it not?
Do you know that amplitude in advance?

[John Devereux]

We know it's really, really low because much better funded groups than
you are arguing over whether it is there at all!

--

John Devereux

[The Great Attractor]

On Fri, 23 Mar 2012 13:38:42 +0000, John Devereux <jo...@devereux.me.uk>
wrote:

Uncle Al would certainly laugh the fuckhead right out of the room.

[Jan Panteltje]

On a sunny day (Fri, 23 Mar 2012 13:38:42 +0000) it happened John Devereux
<jo...@devereux.me.uk> wrote in <87k42b1...@devereux.me.uk>:

OK, 'funded' Ha, what a joke.
Now lets talk some numbers, you have read the Russian paper[1] too of course.
I worked a bit on my test setup, and now can easily get about a volt signal into
an ADC with a volt reference.
A 10 bit ADC.
So that makes 1024 steps, or 1/10 of a percent sensitivity.
Now lets allow for some drift due to whatever in the setup,
even if we play thermostat, and then we are still good to detect 1% changes.
If it is less than 1% then I am not interested in the effect, as then it has
no practical value for me, I am not CERN (Crazy Expensive Return Nothing),
I am doing it so if the effects exist so I can use them.
There must a be, always, a practical application of what you do.
Else it becomes like string theory, or the CERN particle zoo,
where all you have is an A4 piece of paper with a theory of almost everything,
except what you need to advance, oh and that needs more funding.
So 1% or a bit better will do, and I do not give a f*ck about what anybody thinks
it SHOULD be, unless they get of their rear end and do an experiment themselves.
Then I will listen.

This is a fun project and any kid of any age can do it, with just pocket money.
Also old kids like me.

I challenge anyone here with the numbers.

Now sure if you want to donate a million $ to support the experiment, then I will accept those
and go to a nice warm island with hulahoop girls and cool drinks and dream about building stuff.
I would not, really, go live in a tunnel on the border of Switzerland and H.. sorry some other country.
:-)

[Jan Panteltje]

On a sunny day (Fri, 23 Mar 2012 15:06:56 GMT) it happened Jan Panteltje
<pNaonSt...@yahoo.com> wrote in <jki3im$1cv$1...@news.albasani.net>:

>Now lets talk some numbers, you have read the Russian paper[1] too of course.

[1]
I am 99% sure the effect they did see is due to earth magnetic field.
they wen to the north pole with some expedition and there the effect was zero.
Sign on the wall.

[josephkk]

On Tue, 20 Mar 2012 18:59:43 -0800, Robert Baer <rober...@localnet.com>
wrote:

>Jan Panteltje wrote:
>> This is an idea for an experiment I may or may not do.
>> The background:
>> There have been reported seasonal variations in radioactive decay in the past.
>>
>> Now If I took a simple tritium light, and a good quality photo-diode,
>> put both in a light proof box,
>> and logged that with a 10 bit PIC ADC with a decent Vref for say a year
>> to FLASH, say 1 sample / hour, run the whole thing of some battery.
>> 10 bits per hour makes 87660 bits per year, or 10950 bytes per year.
>> Have the PIC wake up once every hour to save power.
>>
>> Would the light intensity from a tritium light be [linear] proportional
>> to the decay of the tritium?
>> And then next year analyze the result (if any)?

> Decay is exponential - remember? Half-Life. If half life is a year,
>then after one hear half has decayed, the next year half of that has
>decayed, etc so look at it as an RC decay with time constant of a year -
>and in 5 years (5*tc) it would be essentially completely decayed.
> So...
> That sampled light should show that same RC type drop (linear
>relationship between decay, emission, and light).

Not to mention in design of experiment, you want to obtain the best
reasonably achievable signal to noise ratio, thus half lives on the order
of kiloyears. Rather than swamp the desired signal under an unduly short
half life.

?-)

[Jamie M]

I remember you saying you have some PMT's, if the tritium could replace
the phosphor in a PMT, then it would just be an electron multiplier
tube getting electrons from the tritium and would be more sensitive
than having to measure the light off a phosphor, should be able to
detect each electron emitted from the tritium atoms?

cheers,
Jamie


>
>

[Martin Brown]

The variation is <0.1% if it is at all real. The variation observed
tracks the external ambient temperature at the sites rather better than
it matches the hypothetical inverse square law neutrino flux or scalar
field that the proponents of this effect suggest as an explanation.

http://arxiv.org/pdf/0808.3283v1.pdf

If the signal had tracked solar distance and in phase with it then I
would be much more inclined to think they have something real.

It requires considerable effort to obtain a consistent flux calibration
across long timescales - usually against another reference source of
similar flux levels but with a very different (ie long half life).

That way any obvious deadtime corrections and common mode systematic
errors can be eliminated from the experimental method.

--
Regards,
Martin Brown

[Jan Panteltje]

On a sunny day (Fri, 23 Mar 2012 20:43:37 -0700) it happened Jamie M
<jmo...@shaw.ca> wrote in <jkjftf$ddt$1...@speranza.aioe.org>:

>I remember you saying you have some PMT's, if the tritium could replace
>the phosphor in a PMT, then it would just be an electron multiplier
>tube getting electrons from the tritium and would be more sensitive
>than having to measure the light off a phosphor, should be able to
>detect each electron emitted from the tritium atoms?

The big problem with PMTs is that they are so sensitive to magnetic fields.
Even the earth magnetic field, and especially at low anode voltages,
as then the electrons have low speed and are easily deflected.
I think magnetic influences can explain the seasonal changes in the
Russian experiment with Plutonium, more current the electric
wiring in the winter (light on longer) than in the summer,
it could even be somebody walking in with a steel watch that is slightly magnetic,
I have tried walking about with a magnet with the tritium light
taped to the front of the PMT, and measuring the voltage
drop over the PMT anode resistor, 10% changes at 1 meter are normal.
So that rules out, for an experiment that has to run so long, PMTs.
I was very happy and actually surprised that the tritium light does not seem
to react to a powerful magnet right next to it.,
One systematic error less to worry about.

[Jan Panteltje]

On a sunny day (Sat, 24 Mar 2012 09:37:18 +0000) it happened Martin Brown
<|||newspam|||@nezumi.demon.co.uk> wrote in <nBgbr.8124$dq4...@newsfe23.iad>:

>On 23/03/2012 13:38, John Devereux wrote:
>> Jan Panteltje<pNaonSt...@yahoo.com> writes:
>>
>>> On a sunny day (Fri, 23 Mar 2012 08:56:16 +1000) it happened Adrian Jansen
>>> <adr...@qq.vv.net> wrote in
>>> <4f6bae17$0$29999$c3e8da3$5496...@news.astraweb.com>:
>>>
>>>> Your experimental noise means you can never be sure that you have a
>>>> 'real' cycle after only one period.
>>>
>>> That depends on the amplitude of the signal you get now does it not?
>>> Do you know that amplitude in advance?
>>
>> We know it's really, really low because much better funded groups than
>> you are arguing over whether it is there at all!
>
>The variation is <0.1% if it is at all real. The variation observed

The paper you refer to does not seem to support that,
I see 3.10^-3.

>tracks the external ambient temperature at the sites rather better than
>it matches the hypothetical inverse square law neutrino flux or scalar
>field that the proponents of this effect suggest as an explanation.
>
>http://arxiv.org/pdf/0808.3283v1.pdf


>If the signal had tracked solar distance and in phase with it then I
>would be much more inclined to think they have something real.

Well, the experiment is now with tritium, and the result, if any,
will be added to the pool of knowledge of the human beans[1].

[1] LOL

[josephkk]

On Fri, 23 Mar 2012 20:43:37 -0700, Jamie M <jmo...@shaw.ca> wrote:

>
>> Overall the whole experiment should be in a thermally insulated box with metal shielding I think,
>> as already in the tests setup EM interference can mess up things.
>> Jippee!
>> We are sailing.
>
>I remember you saying you have some PMT's, if the tritium could replace
>the phosphor in a PMT, then it would just be an electron multiplier
>tube getting electrons from the tritium and would be more sensitive
>than having to measure the light off a phosphor, should be able to
>detect each electron emitted from the tritium atoms?
>
>cheers,
>Jamie

When i see a post like this it makes my soul hurt. There is no phosphor
in a PMT. Just a sensitive photocathode, dynodes, and ending with an
anode, where the output signal occurs.

?-0

[Jamie M]

You'd make a good school teacher!

cheers,
Jamie

>
> ?-0

[Jan Panteltje]

I wrote:
>This is an idea for an experiment I may or may not do.
>The background:
>There have been reported seasonal variations in radioactive decay in the past.
>
>Now If I took a simple tritium light, and a good quality photo-diode,
>put both in a light proof box,
>and logged that with a 10 bit PIC ADC with a decent Vref for say a year
>to FLASH, say 1 sample / hour, run the whole thing of some battery.
>10 bits per hour makes 87660 bits per year, or 10950 bytes per year.
>Have the PIC wake up once every hour to save power.

Some design decision have been taken, and here a picture of the box
the experiment will be in:
http://panteltje.com/pub/tritium_decay_experiment_box_1_IMG_3380.JPG

The black, lightproof, inner box will house the temperature controlled
tritium light, photo diodes, and pre-amplifier.
The PCB will hold a PIC 18F14K22 and some other electronics, a power MOSFET
to control the heater resistors glued to the tritium light in the black box.
The photo diodes will be 2 Osram BPW21, visible light range,
as I use a white tritium light (those come in many colors,
depends on the phosphor used).
One photo diode will be blacked with paint, both will be glued against
the temperature stabilized tritium light.
A LM335 sensor will be glued against the tritium light too.
The tritium light will be held at a constant temperature of 45 C,
plus or minus 1/2 C, heated by resistors.

I have made 2 designs for the preamp, and will try both to
see what is the most stable, one a differential current amplifier
with transistors, and one using CMOS opamps, both designs
are truly 100% differential
The PIC will use its internal reference of 1.024 V, if this
was to prove to drift in temperature tests, then the PIC will be moved into the back box too.
The rest of the box will be filled with Duracell AA batteries,
and there will be a connection to the outside for a 12V AC/DC adaptor.
There will be a RS232 connector so the PIC can be read out at any time
to check temperature stability and data acquisition.
Data will be stored to FLASH memory, with the option
of an external to the PIC FLASH chip for longer runs.
The box will be filled with more thermo padding material.
All inputs and output will be RF decoupled, and the RF screening is why the larger alu box.

The thing will be placed in a place away from direct sunlight and extreme temperature
variations.

Thermal stabilization requires some power, if I can make 100 C/W on the tritium
light and preamp box, and have an average of 45 - 21 = 24 C over-temperature,
than that means I need to heat with 24 /100 W, or say 250 mW.
This is where the AC adaptor comes in, as about 1 Ah / 4 V batteries means
4 Wh, or 16 hours for the experiment to keep running without AC power.
I do not expect a total of 16 hours mains down time in one year.
Decisions, decisions.
Parts are on order, sailing on.

Things may still change at this point as the project unfolds.

[George Herold]

Neat, Not all plastic will block NIR light. You'll want to check how
light tight the box is. (Just 'cause you can't see through it doesn't
mean that the photodiode can't.) (sorry for that triple negative.)

George H.

[Johann Klammer]

Jan Panteltje wrote:
> The photo diodes will be 2 Osram BPW21, visible light range,

I think the BPW34 has a slightly higher spektral sensitivity, as well as
quantum yield. It is a PIN photodiode.

[Jan Panteltje]

On a sunny day (Mon, 26 Mar 2012 08:24:45 -0700 (PDT)) it happened George
Herold <ghe...@teachspin.com> wrote in
<5c6bf5c9-2724-4590...@h5g2000vbx.googlegroups.com>:

>Neat,

Thanks

>Not all plastic will block NIR light. You'll want to check how
>light tight the box is. (Just 'cause you can't see through it doesn't
>mean that the photodiode can't.) (sorry for that triple negative.)

Yes, I have been holding it against the sun etc.
Of course it is the second barrier, the alu box is the first,
so it is not going to see a lot of IR.
But if measurements turn out to show some effect o sunlight
on the setup, then I can add some black paper wraps,
paint inside of alu box black, lots of possibilities.

[Jan Panteltje]

On a sunny day (Mon, 26 Mar 2012 19:09:24 +0200) it happened Johann Klammer
<klam...@NOSPAM.a1.net> wrote in
<4f70a2c0$0$1577$91ce...@newsreader04.highway.telekom.at>:

Yes, 0.9 electrons per 'photon' IIRC.
OTOH the spectrum is wider (to 1100 nm, and we do not want any IR
sensitivity.
Actually the light from the tritium tube is not really that low
in absolute sense, I got good signal with Nichia green LEDs as sensor.
I hope the BPW21 will give a lot more signal than the LEDs.
As to PIN, speed is no issue, in fact slower is better (integrating
over individual flashes of the tritium tube, but I also use a triple RC
filter as integrator.
So the choice between the BPW34B and the BPM21 was a very conscious one.

[Ralph Barone]

And one year from now, Jan discovers that the paint he used to obscure one
photo-diode was mildly radioactive...

Keep it up and report back in a year. This is truly science.

[josephkk]

I may try that yet.

?-)

[Jan Panteltje]

Design changes:

Acquisition data will be stored in a 24LC256 i2c serial EEPROM (on order).
I ran out of enough code space in the 18F14K22 to store 8760 x 2 bytes (24 hours x 365 days),
as I have a lot of extra test stuff added.
Now I have 32 kB.

As the 18F14K22 SPI is broken, and the i2c uses the same hardware,
I wrote i2c software today to write and verify the data, just in case.
I replaced the LM335 temp sensor with a normal Si diode,
smaller thermal mass, and the about .7Vis right in the middle of the ADC range,
the LM has 3.21 V at 45 C, so that would have to be divided, losing accuracy,
or some opamp offset circuit, diodes are good temp sensors, used them before.
Will calibrate using my thermocouples and EEPROM setpoint.
Photocells should be here Wednesday, curious....

[hamilton]

On 3/27/2012 1:11 PM, Jan Panteltje wrote:

> As the 18F14K22 SPI is broken,

Whats broken with the SPI ??

[George Herold]

Hey Jan, I was thinking about you design last night. Why the two
photodiodes? If you want the lowest leakage then don't bias the
photodiode. Just ground one side and run the other into a TIA. You
don't need any speed. And with a grounded photodiode and no light the
only offset will be from the opamp. (Vos and I-bias* R-feedback)

George H.

[Jan Panteltje]

On a sunny day (Tue, 27 Mar 2012 13:50:41 -0600) it happened hamilton
<hami...@nothere.com> wrote in <jkt5mk$q09$1...@dont-email.me>:

>On 3/27/2012 1:11 PM, Jan Panteltje wrote:
>
>> As the 18F14K22 SPI is broken,
>
>Whats broken with the SPI ??

I would have to look it up,
but it was reported here by me last year, google may still have it.
Let me look in my ownw archive, moment...

Ok this I ran into when I wanted to drive the Microchip ethernet chip
from th 18F14K22 with SPI, in may last year I wrote:

>After waisting some hours to get SPI working with the PIC 18F14K22 connected to an ENC28J60 Ethernet cotroller,
>and finally grabbing the scope, I found it sort of always loses bit 0 in the SPI.
>So looking for that sort of disaster with googke pointed to the 'errata',
>well I should have looked for that first, so anyways, that 'errata' says:

>4. Module: MSSP (Master Synchronous
> Serial Port)
> 4.1 In I2CTM Master mode, baud rates obtained
> by setting SSPADD to a value less than
> 0x03 will cause unexpected operation.
> Work around
> Ensure SSPADD is set to a value greater
> than or equal to 0x03.
> Affected Silicon Revisions
> A1 A2 A3 A7 A8
> X X X X
> 4.2 In SPI Master mode, when the CKE bit is
> cleared and the SMP bit is set, the last bit of
> the incoming data stream (bit 0) at the SDI
> pin will not be sampled properly.
> Work around <--------------------------------------------------- throw chip away and find an other if you need this
> None.
>
> Affected Silicon Revisions
> A1 A2 A3 A7 A8
> X X X X
> 4.3 When SPI is enabled in Master mode with
> CKE = 1 and CKP = 0, a 1/FOSC wide pulse
> will occur on the SCK pin.
> Work around
> Configure the SCK pin as an input until after
> the MSSP is setup.
>
>Affected Silicon Revisions
> A1 A2 A3 A7 A8
> X X X X
>
>4.4 In I2C Master mode, SSPADD values of
> 0x00, 0x01, 0x02 are invalid. The current I2C
> Baud Rate Generator (BSG) is not set up to
> generate a clock signal for these values.
> Work around <--------------------------------------------------- throw chip away and find an other if you need this
> None.
>
>Affected Silicon Revisions
> A1 A2 A3 A7 A8
> X X X X
>
>
>4.5 In I2C Master mode, the RCEN bit is not
> cleared by hardware if improper Stop is
> received on the bus.
> Work around
> Reset the module via clearing and setting
> the SSPEN bit of SSPCON1.
>Affected Silicon Revisions
> A1 A2 A3 A7 A8
> X X X X
>
>
>4.6 In SPI Master mode, when the SPI clock is
> configured for Timer2/2 (SSPCON1
> <3:0> = 0011), the first SPI high time may
> be short.
> Work around
> Option 1: Ensure TMR2 value rolls over to
> zero immediately before writing to
> SSPBUF.
> Option 2: Turn Timer2 off and clear TMR2
> before writing SSPBUF. Enable
> TMR2 after SSPBUF is written.
>Affected Silicon Revisions
> A1 A2 A3 A7 A8
> X X X X
>
>4.7 In any SPI Master mode, SCK = TMR2/2, if
> SSPBUF is written to while shifting out data,
> a ninth SCK pulse is incorrectly generated.
> At that point, the module locks the user from
> writing to the SSPBUF register, but a write
> attempt will still cause 8 or 9 more SCK
> pulses to be generated.
>
> Work around
> The WCOL bit of the SSPCON register is
> correctly set to indicate that there was a write
> collision. Any time this bit is set, the module
> must be disabled and enabled (toggle
> SSPEN) to return to the correct operation.
> The bus will remain out of synchronization.
>Affected Silicon Revisions.
> A1 A2 A3 A7 A8
> X X X X
>---------------------------------------------------------------
>
>Looks bit like those old Intel erratas, that got me in the past.
>Do they not want people to use their chips?

[Jan Panteltje]

On a sunny day (Tue, 27 Mar 2012 12:54:57 -0700 (PDT)) it happened George
Herold <ghe...@teachspin.com> wrote in
<3a88efe3-9b1b-404d...@9g2000vbq.googlegroups.com>:

>Hey Jan, I was thinking about you design last night. Why the two
>photodiodes? If you want the lowest leakage then don't bias the
>photodiode. Just ground one side and run the other into a TIA. You
>don't need any speed. And with a grounded photodiode and no light the
>only offset will be from the opamp. (Vos and I-bias* R-feedback)
>
>George H.

The reason is the temperature drift of the dark current,
keeping 2 photodiodes in your configuration, but connected the
opposite way, one in the dark, eliminates any changes in dark current
to a large extend.
At least I hope so.

I have made 2 designs, one with TIA as you suggest,
I will do some measurement as soon as those diodes arrive,
R-feedback is very big... :-)

[George Herold]

On Mar 28, 4:45 am, Jan Panteltje <pNaonStpealm...@yahoo.com> wrote:
> On a sunny day (Tue, 27 Mar 2012 12:54:57 -0700 (PDT)) it happened George

> Herold <gher...@teachspin.com> wrote in
> <3a88efe3-9b1b-404d-8de4-e0986e252...@9g2000vbq.googlegroups.com>:

>
> >Hey Jan,  I was thinking about you design last night.  Why the two
> >photodiodes?  If you want the lowest leakage then don't bias the
> >photodiode.  Just ground one side and run the other into a TIA.  You
> >don't need any speed.  And with a grounded photodiode and no light the
> >only offset will be from the opamp. (Vos and I-bias* R-feedback)
>
> >George H.
>
> The reason is the temperature drift of the dark current,

With no voltage across the PD there is no dark current.

> keeping 2 photodiodes in your configuration, but connected the
> opposite way, one in the dark, eliminates any changes in dark current
> to a large extend.
> At least I hope so.
>
> I have made 2 designs, one with TIA as you suggest,
> I will do some measurement as soon as those diodes arrive,
> R-feedback is very big... :-)

More than one Giga ohm?

George H.

[Jan Panteltje]

About measuring light and dark....

After some math, and remembering the great advice from J Larkin CEO of Highland Electronics
regarding averaging of ADC values,
it looks like I am going to use 2 completely identical gain channels,
one with the photo cell (arrived today, man those are big) looking at the tritium light,
and the other one with the photo cell painted black,
but mounted on the same tritium light to get thermal coupling[1].

Samples are taken of both inputs every second, added to a total for each,
and after 3600 seconds, one hour, the total is divided by 3600,
and BOTH samples (light and dark channel) will be stored.
Storing light an dark values makes it easier later, during data analysis,
to find systematic errors.
Averaging every time of 3600 samples gets at least rid of some noise.
There is also RC filtering.

A third ADC channel measures the voltage drop over a si diode that is
also thermally coupled to the tritium light,
This temperature channel is also sampled once per second,
and used to set a PWM value (PID controller) that drives a IRLZ34 power MOSFET that
heats 2 resistors that are also thermal coupled to the tritium tube [2].
The 'D' in the PID is zero, I expect a worst case lock in for the temperature
regulator of about 2 minutes, this startup time is not so important,
acquisition will not start until the temperature is in range.
A fourth ADC channel also sampled 1 x per second, measures the battery backup voltage.

I am thinking about a fifth channel to measure a second external to the PIC reference,
(MCP1525, a 2.5 V reference), to be able to detect reference voltage changes of the PIC
internal reference.
That MCP1525 is there for supply stabilization anyways.

Timing:
I have one PIC running on a 32 kHz watch crystal (lightning detector circuit),
and that only wakes up when needed, but in this case as we run from a wallwart normally,
I will use a 10 MHz crystal, no PLL multiplier, such a still low frequency only consumes a few mA.
It is more accurate than the PIC internal oscillator (that one is 2%), so the timing
intervals are more the same.
In absolute sense it does not matter if the one hour is exactly one hour,
because if you stop the experiment after exactly one year, and you find you have n
samples, then you know the sample duration was 365 x 24 / n hours.
And you can still draw the exact graph of the light variation, all of course
if all the sample intervals had the same length, the crystal oscillator makes sure that
is to better than 10^-4, no calibration needed.

Now to measure them photo diodes, weekend coming up, soldering iron next to me,
most parts have arrived, even did draw a diagram...

[1] May all change after I measured the new photo diodes.
[2] Will the PWM changes (because of external temperature changes) affect the input signals?
Maybe I should filter and run the heating resistors with DC?

[Jan Panteltje]

Photo cell test
did a simple photo cell test today:
http://panteltje.com/pub/da_test_setup_IMG_3382.JPG

The signal is amplified by a very simple one stage amplifier,
a TCL247 CMOS opamp, with a (YES!) 120 MOhm resistor in the feedback.
About 6 V supply, no bias on the photo diode.
This is what we get if dark (no tritium light):
http://panteltje.com/pub/dark_signal_IMG_3384.JPG
that is 15 mV.

And this is what we get with the tritium light:
http://panteltje.com/pub/tritium_signal_IMG_3388.JPG
847 mV.

Nice within the ADC range of 1.024 V,
and due to the radioactive decay it will only get lower over time.

As I did not screen anything, scoping revealed hum:
http://panteltje.com/pub/bit_of_hum_IMG_3391.JPG
This is after connecting 470 pF parallel to the 120 MOhm,
bigger capacitor values caused the opamp to oscillate at RF.
Of course this is not the final setup and circuit,
just needed to get an idea of the signal levels with these BPW21 photo diodes.
All very nice, very sensitive photo diodes really,
good dark performance too.
Exceeds my expectations.

470p
---||---
| 120M |
-----====-----
| - |
|| ----------- |\ |
|| | + | >------------- multi meter --
|| --- ---|/ TCL247 |
|| / \ BPW21 | |
|| --- /// ///
|| |
|| ///
The TCL247 allows you to drive the inputs below Vss,
common mode range is to -.2 V.

So, now we know some real values, and can proceed.

[be...@iwaynet.net]

On 3/30/2012 10:28 AM, Jan Panteltje wrote:
> Photo cell test
> did a simple photo cell test today:

Jan, I recommend you change your circuit. You want to put the diode on
the + terminal rather than have it part of the gain circuit.

Also I would recommend operating diode in reverse biased mode rather
than in the non-linear voltage generation mode.

And of course the entire apparatus should be inside copper box to shield
from hum.

[Jan Panteltje]

On a sunny day (Fri, 30 Mar 2012 11:28:36 -0400) it happened
"BJA...@teranews.com" <be...@iwaynet.net> wrote in
<yikdr.18703$Yx.1...@newsfe04.iad>:

I think this is not correct.
Look at the diode as a current source,
after all electrickity is about ELECTRONS,
the current is compensated by the current Vout / 120M (R-feedback).
There is no 'voltage' at the - input, it is kept at zero by the opamp!

>Also I would recommend operating diode in reverse biased mode rather
>than in the non-linear voltage generation mode.

No, again, this is about electrons, all of electronics is about electrons,
little charged balls, that move, no other way to understand electronics,
everything else is illusion or in short bullshit.

>And of course the entire apparatus should be inside copper box to shield
>from hum.

The thing is in a light proof box within an alu box:
http://panteltje.com/pub/tritium_decay_experiment_box_1_IMG_3380.JPG
I did this test with the alu box closed.
Copper is heavy, expensive, and has no advantage over alu here.
The parts inside of the black box will be kept at a constant temperature too.

[be...@iwaynet.net]

On 3/30/2012 12:57 PM, Jan Panteltje wrote:
> On a sunny day (Fri, 30 Mar 2012 11:28:36 -0400) it happened
> "BJA...@teranews.com"<be...@iwaynet.net> wrote in
> <yikdr.18703$Yx.1...@newsfe04.iad>:

>> Jan, I recommend you change your circuit. You want to put the diode on
>> the + terminal rather than have it part of the gain circuit.
>
> I think this is not correct.
> Look at the diode as a current source,
> after all electrickity is about ELECTRONS,
> the current is compensated by the current Vout / 120M (R-feedback).
> There is no 'voltage' at the - input, it is kept at zero by the opamp!

Um, yes, it is a current source. (more or less) The problem is you are
running it unbiased and you are putting the diode in the
gain-determining feed back. But in a way it doesn't matter be cause no
matter how non-linear you've made your circuit, you are only looking for
differences anyway. Op amp thermal drift could be a problem, however.

>> Also I would recommend operating diode in reverse biased mode rather
>> than in the non-linear voltage generation mode.
>
> No, again, this is about electrons, all of electronics is about electrons,
> little charged balls, that move, no other way to understand electronics,
> everything else is illusion or in short bullshit.

You have already agreed with me above, you just don't understand that to
diode will work much better reverse biased (note 10 volts max)to insure
that all electrons as you think they are are collected. Look around for
some photo diode circuits and you may see what I mean. Running the diode
at zero volts will not give any kind of linear stable output.

>> And of course the entire apparatus should be inside copper box to shield
>>from hum.
>
> The thing is in a light proof box within an alu box:
> http://panteltje.com/pub/tritium_decay_experiment_box_1_IMG_3380.JPG

Yeah, aluminum should work fine. It's just harder to make good contact
on seams with aluminum.

[Jan Panteltje]

On a sunny day (Fri, 30 Mar 2012 14:24:24 -0400) it happened
"BJA...@teranews.com" <be...@iwaynet.net> wrote in
<nTmdr.24471$yD7....@newsfe15.iad>:

>On 3/30/2012 12:57 PM, Jan Panteltje wrote:
>> On a sunny day (Fri, 30 Mar 2012 11:28:36 -0400) it happened
>> "BJA...@teranews.com"<be...@iwaynet.net> wrote in
>> <yikdr.18703$Yx.1...@newsfe04.iad>:
>
>>> Jan, I recommend you change your circuit. You want to put the diode on
>>> the + terminal rather than have it part of the gain circuit.
>>
>> I think this is not correct.
>> Look at the diode as a current source,
>> after all electrickity is about ELECTRONS,
>> the current is compensated by the current Vout / 120M (R-feedback).
>> There is no 'voltage' at the - input, it is kept at zero by the opamp!
>
>Um, yes, it is a current source. (more or less) The problem is you are
>running it unbiased and you are putting the diode in the
>gain-determining feed back.

No no, do not run in front of the wagon...
Let's do some math (EEEEEEHHH), I measure .847 V.
The feedback resistor is 120 M, so now we know the current from the diode
.847 / 120.10^6, or about 7 nA. (nano ampere).
Now lets look up the definition of Ampere:
http://en.wikipedia.org/wiki/Ampere
6.241 × 10^18 electrons / second.

So 7 nA is 7 x 6.241 x 10^9 = 43.687 x 10^9 electrons per second.

The quantum efficiency of the BPW21 photo diode is specified as .8 electrons per photon[1].
So now we know we had .8 x 43.687 x 10^9 = 34.9496 x 10^9 photons per second
hitting the photo diode.
Nothing 'more or less' linear, just simply linear.
I have assumed a perfect opamp here.

(Hope I did the math right, its late here, but just for the curious),

But in a way it doesn't matter be cause no
>matter how non-linear you've made your circuit, you are only looking for
>differences anyway. Op amp thermal drift could be a problem, however.

Right that is why the thing will be kept at 45 C.
That includes the opamp, the tritium tube, and the photo diodes.
I may go for +40 C, as the leakage of the opamp goes up very fast with temperature.
When kept out of the sun it is never hotter than 35 C here.

>diode will work much better reverse biased (note 10 volts max)to insure
>that all electrons as you think they are are collected. Look around for
>some photo diode circuits and you may see what I mean. Running the diode
>at zero volts will not give any kind of linear stable output.

See the math above.

>>> And of course the entire apparatus should be inside copper box to shield
>>>from hum.
>>
>> The thing is in a light proof box within an alu box:
>> http://panteltje.com/pub/tritium_decay_experiment_box_1_IMG_3380.JPG
>
>Yeah, aluminum should work fine. It's just harder to make good contact
>on seams with aluminum.

Never had a problem with that with these boxes.
The surface where the parts touch is very big.

Painted boxes *are* a problem.

[1] it is NOT specified as *volts* per photon, but as electrons per photon.
I have played a bit with it in just plan daylight (no direct sunlight cloudy),
I get 30 uA on a moving coil meter when connected to the BPW21,
you could make a crystal radio amplifier with it.
1000 would drive a toy car..
:-)

[Jan Panteltje]

I wrote:

>No no, do not run in front of the wagon...
>Let's do some math (EEEEEEHHH), I measure .847 V.
>The feedback resistor is 120 M, so now we know the current from the diode
>.847 / 120.10^6, or about 7 nA. (nano ampere).
>Now lets look up the definition of Ampere:
> http://en.wikipedia.org/wiki/Ampere
> 6.241 × 10^18 electrons / second.
>
>So 7 nA is 7 x 6.241 x 10^9 = 43.687 x 10^9 electrons per second.
>
>The quantum efficiency of the BPW21 photo diode is specified as .8 electrons per photon[1].
>So now we know we had .8 x 43.687 x 10^9 = 34.9496 x 10^9 photons per second
>hitting the photo diode.

Knew it, late, math...
(1 / .8) x 43.687 = 54,6 x 10^9 photons per second
Or whatever else I did wrong.

[George Herold]

I don't know the TCL427, but is the 15mV due to the input bias
current. Does that go up with temperature?

George H.

[George Herold]

On Mar 30, 12:57 pm, Jan Panteltje <pNaonStpealm...@yahoo.com> wrote:
> On a sunny day (Fri, 30 Mar 2012 11:28:36 -0400) it happened

> "BJAC...@teranews.com" <b...@iwaynet.net> wrote in
> <yikdr.18703$Yx.11...@newsfe04.iad>:

> The parts inside of the black box will be kept at a constant temperature too.- Hide quoted text -
>
> - Show quoted text -

Yeah the circuit is fine, nice and linear. Just not as fast the diode
is not reversed biased.

George H.

[George Herold]

On Mar 30, 2:24 pm, "BJAC...@teranews.com" <b...@iwaynet.net> wrote:
> On 3/30/2012 12:57 PM, Jan Panteltje wrote:
>
> > On a sunny day (Fri, 30 Mar 2012 11:28:36 -0400) it happened

> > "BJAC...@teranews.com"<b...@iwaynet.net>  wrote in
> > <yikdr.18703$Yx.11...@newsfe04.iad>:

> >> Jan, I recommend you change your circuit. You want to put the diode on
> >> the + terminal rather than have it part of the gain circuit.
>
> > I think this is not correct.
> > Look at the diode as a current source,
> > after all electrickity is about ELECTRONS,
> > the current is compensated by the current Vout / 120M (R-feedback).
> > There is no 'voltage' at the - input, it is kept at zero by the opamp!
>
> Um, yes, it is a current source. (more or less) The problem is you are
> running it unbiased and you are putting the diode in the
> gain-determining feed back. But in a way it doesn't matter be cause no
> matter how non-linear you've made your circuit, you are only looking for
> differences anyway. Op amp thermal drift could be a problem, however.
>
> >> Also I would recommend operating diode in reverse biased mode rather
> >> than in the non-linear voltage generation mode.
>
> > No, again, this is about electrons, all of electronics is about electrons,
> > little charged balls, that move, no other way to understand electronics,
> > everything else is illusion or in short bullshit.
>
> You have already agreed with me above, you just don't understand that to
> diode will work much better reverse biased (note 10 volts max)to insure
> that all electrons as you think they are are collected. Look around for
> some photo diode circuits and you may see what I mean. Running the diode
> at zero volts will not give any kind of linear stable output.

It's a prefectly fine linear circuit. Reverse biasing will only
increase the speed, by reducing the diode capacitance.

George H.

[Jamie M]

Hi Jan,

Crazy idea for you: to get more dynamic range of the light signal you
could accelerate the emitted electrons in the tritium light tube, and
target the electrons to a small spot on the surface of the tube to get
a brighter light. From wikipedia: http://en.wikipedia.org/wiki/Tritium
the tritium beta/electron decay energy is about 18keV, so I guess
you would need more than this to notice an effect on the electrons.

cheers,
Jamie

[Jan Panteltje]

To reduce drift due to temperature changes caused by
external changes in temperature and by heat generated in the electronics,
it is important to know what the thermal resistance in degrees centigrade per watt
of the little black box with the critical temperature sensitive components is.
So that we know how many watts the temperature controller needs to put in to
keep temperature constant.
A simple way to found that out, is put 1 Watt heat in, and measure the temperature rise.
One should of course do that with a 1 watt capable resistor, not with an 1/8 or 1/4 as I did here,
as else the consequences are as shown here.

Anyways I found the value.
I took a 12 Ohm resistor, and my thermocouple sensor as described here
http://panteltje.com/panteltje/pic/th_pic/
and put those in the small black box.

The small black box was put into the big alu box surrounded by thermal padding:
http://panteltje.com/pub/thermally_insulating_the_box_IMG_3399.JPG
http://panteltje.com/pub/thermal_test_without_cover_IMG_3398.JPG
Finally the alu box was closed:
http://panteltje.com/pub/thermal_test_with_cover_IMG_3397.JPG
you can see the heating cable and the thermocouple wires coming out, if only my ISP
did not f*ck up my picture uploads, stay clear of godaddy [2]!


Then I fed it with 1 watt of electrickity:
http://panteltje.com/pub/1_watt_input_IMG_3392.JPG
using my lab supply described here:
http://panteltje.com/panteltje/pic/pwr_pic/
this thing saves you calculating current x voltage, so that makes things so much easier :-)

I waited and waited, and yes I did put up the power to 2.5W for a short while,
should not have done that, went back to 1W, and did read out the temperatures after an hour or so.
http://panteltje.com/pub/22.5C_per_watt_IMG_3396.JPG
The cold side was 23.9 and the box was 46.4 (channel 1), makes 22.5 C temperature rise for 1 W input [1]
This is what I wanted to know, and opened the alu box to find this:
http://panteltje.com/pub/melted_box_IMG_3401.JPG
Now should not have done the 2.5 W....
Further inspection after opening the black box showed this:
http://panteltje.com/pub/burned_resistor_in_box_IMG_3404.JPG

Anyways, now I can proceed, the neural net has some more ideas of power and reality,
sometimes called 'experience'.

[1] The resistor melting into the box and the thermocouple wire touching the box
does of course affect the measurement, but in a negative way I think, so the real
thermal resistance will probably be higher,

It all does show quite a bit of power is needed to even maintain a delta t of 22.5C,
for a 40 C working temperature that would mean 40 - 22.5 = 17.5 C minimum outside
temperature for 1 W, this is not acceptable, need at least 2 Watt, makes -5 C
minimum, will keep the experiment in house it should never freeze there.
The 1 to 2 W power means the batteries will have to deliver this during a mains
interruption, for a low voltage of 4 V for the batteries, 2 W is 500 mA,
for 1500 mAh batteries this would cover only 3 hours.

Compromises compromises..

Anyways, it shows you can make most experimental stuff for very little money.


[2]
If you think the pictures look like shit you are right, godaddy changes them!
Comparing what I download back from them to my originals shows they change content,
they perhaps, to rip you of some more, run their webservers in 8 or 16 bit mode?

# wget http://panteltje.com/pub/22.5C_per_watt_IMG_3396.JPG <---- download from my website
--2012-03-31 14:15:40-- http://panteltje.com/pub/22.5C_per_watt_IMG_3396.JPG
Resolving panteltje.com (panteltje.com)... 188.121.54.128
Connecting to panteltje.com (panteltje.com)|188.121.54.128|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 4731 (4.6K) [image/jpeg] <---- downloaded length 4731 bytes
Saving to: 5C_per_watt_IMG_3396.JPG'
2012-03-31 14:15:44 (4.37 KB/s) - 5C_per_watt_IMG_3396.JPG' saved [4731/4731]
# diff 22.5C_per_watt_IMG_3396.JPG /video/a470/all_pics/22.5C_per_watt_IMG_3396.JPG <----- compare to original
Binary files 22.5C_per_watt_IMG_3396.JPG and /video/a470/all_pics/22.5C_per_watt_IMG_3396.JPG differ <----- files differ!!

-rw-r--r-- 1 root root 18762 Mar 31 13:56 /video/a470/all_pics/22.5C_per_watt_IMG_3396.JPG <---- original length was 18762 bytes
So, stay clear of godaddy, of course I complained to them, but they 'cannot see any difference'
and they say they do not have the tools to check their website (like wget?),
I did send them the original as email attachment, then they could not read that email,
bunch of crooks, case for the FBI.
My domain registration with them ends this year.
Do not host your site with godaddy! They are criminals who change content of your original
work and then publish low quality copies for some personal gain.
And those same criminals support hollywood legislation! What a world.
Nukes!
We need more nukes!

[Jan Panteltje]

How about it? Experiments of the third kind , take 999999.
Update
Hotplate design.

After entering the results of the heating experiment into the neural net (mine),
it became clear to that neural net that things should be done differently
than a simple resistor heating the air in a box as a means to keep
component temperature stable.

So then, it was shown to me, that if we mount all the components that we
want to be at a fixed temperature on a 'hotplate', in this case a small aluminum
plate, and heat it with a nice TO220 type transistor, then if we keep
'hotplate' free from the box, we can make a nice even temperature with
very little input power for the heater.
So after some sawing and drilling I changed pictures of solution presented
by the neural net into something real in the material world:
http://www.panteltje.com/pub/hotplate_components_positioning_IMG_3414.JPG
The components will be glued on the alu plate, there will be no PCB,
as leakage would ruin everything anyways with 120 MOhm resistors,
would need guard bands, what not.
from left to right
tritium tube, one of the photo cells (those will be directly connected to the opamp next to
it and in thermal contact with the tritium tube), the TLC274 quad opamp,
a 10 MHz crystal, a PIC 18F14K22 microcomputer with multi channel ADC and PWM output,
and 2 24LC256 EEPROMs for data storage (dark and light values, plus some more,
no need to hold these at a fixed temp, maybe even keep them cooler,
these chips in the pictures are smaller ones, still waiting for the big ones),
so maybe keep them out of the box? [1]

Anyways, below the hotplate is the hotplate heater:
http://panteltje.com/pub/IRLZ34N_heating_element_IMG_3416.JPG
it has 2 functions, heating the hotplate, and keeping it separated from the black plastic box.
This shows the bottom of the box, the washer will keep it separated from the PCB it is mounted on.
http://panteltje.com/pub/thermos_box_mounting_plus_heater_circuit_diagram_IMG_3415.JPG
Also it shows some sketch of the circuit diagram mentioned neural net came up with,
so to run the heater from the PIC PWM but with practically DC so we have no interference,
the hotplate is floating here, but if collected to the drain of the IRZ43N MOSFET it would be
at +4 V, and that would be stabilized and fine too, give better thermal contact.
We will see.
I will use a plastic bolt, as soon as I get near a hardware shop that has those in M3 size,
bit difficult on Sunday.
Plastic will give better thermal insulation.

So next is superglue, or / and maybe 2 components glue, we have that at hand,
There are of course more components, but mainly some small capacitors and some very small SMD resistors
that can easily fit between IC pins etc..
I will not make a guess how much less power we will need in this setup to keep
say the tritium tube at 40C, but ... OK.
You can do and place bets of course, if somebody takes them.
I think this is a cool circuit.


[1]
The big thermal leakage is now likely to come from the wires going in and out of the black box.
we need:
ground
power +4V (heater)
power +3V (chips)
I2C data perhaps
I2C clock perhaps
RS232 logic level in (MAX232 is on main board
RS232 logic level out
Temperature warning LED out (can be done with I/O expander on main board via same I2C).
So basically if I put the EEPROMs in the black box, I can save 1 copper wire.
And of course what I forgot, but I do not know that yet :-)

[Jan Panteltje]

[WoolyBully]

On Sun, 01 Apr 2012 11:38:27 GMT, Jan Panteltje
<pNaonSt...@yahoo.com> wrote:

>How about it?

Double posting retard!

[Jan Panteltje]

How about it? Experiments of the third kind , take 999999.
Update

Hotplate design,
stabilizing the heater MOSFET

http://panteltje.com/pub/thermos_box_mounting_plus_heater_circuit_diagram_IMG_3415.JPG
shows the quick sketch diagram of the MOSFET driver.
The idea is that the current through the MOSFET is exactly proportional to the input voltage.
As we all know, MOSFETs like to do their thing too,
and in such a configuration like to sing (oscillate).
And so also this circuit.

Playing with it and the oscilloscope a bit did lead to this very quiet circuit,
that within a fraction of a millivolt has the MOSFET drain current follow the input.
There were 2 issues here, 1) MOSFET likes to oscillate, and 2) opamp too.
So sort of separating both from each other worked.

+4V
R1 |
470k + |------
---===--------------|\ 100k 1k |--- |
| | - | >-------===--------===----| |<-- === 1u
control- === ---|/ | |---| |
voltage | 1u | === IRLZ34N | ///
0 to +1 V | C1 | | 1u on |
| /// | TCL274 /// hotplate |
/// | as heater | about 300 mA
-------------------------------------|
|
[ ] 3.3 Ohm
|
///


Having a linear relationship between the control voltage and the output current (power) makes
the software control loop simpler.
Why 1 uF everywhere? I bought a bag of 100.
The 470 K is just for test, this will come from the PIC PWM,
R1 C1 is the lowpass.
100 k and 1k are nice round values.
The 3.3 Ohm was calculated using Ohm law.
The rest ... anyways we need no speed, nowhere in the year long project,
Even outside the black box the hotplate, and so the parts on it, easily meets target
temperature of 40C with about 1,3 W input.
Should be way less watts with it in the black box and thermally insulated on top of that.
As stated before, there will be a 1N4148 diode mounted to the hotplate as temperature sensor.
A PIC microcomputer will do the control loop in software.
Time for pizza (heater is still running).

[Jan Panteltje]

On a sunny day (Sun, 01 Apr 2012 08:04:38 -0700) it happened WoolyBully
<Wooly...@arcticicemasses.org> wrote in
<njrgn7pn4muik230s...@4ax.com>:

The only retard is you and some here who endlessy meouw about nothing going
on in your head.
Lets bring some sanity into usenet, go away!

[Tim Williams]

Try a cap from op-amp output to -input, 100pF is enough. Add a series 10k
resistor between this node (-in with cap) and the shunt resistor, so the cap
has something to work into. Get rid of the 100k series resistor and 1uF
filter cap.

As shown, it'll something between oscillate and motorboat, depending on the
position of the planets. The op-amp is an integrator with 90 degree phase
shift, and the RC following it does the same (for a more limited range of
frequencies). 180 degree phase shift at most any frequency means you're
guaranteed to oscillate somewhere.

You might consider making both series input resistors (the 470k control
voltage filter and the shunt voltage feedback) the same value (100k?) so the
input bias (if any) generates a matching offset on both inputs. As a CMOS
amp, offset won't be the greatest (a few mV, plus input offset bias), but if
this is within a temperature control loop, offset and 1/f noise won't be a
problem.

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms

"Jan Panteltje" <pNaonSt...@yahoo.com> wrote in message
news:jl9spn$igi$1...@news.albasani.net...

[amdx]

Early on, my thought about the heater was multiple resistors, 10, or
20. What ever it took for uniform temperature. You could capture
resistors between the aluminum plate and the plastic housing with or
without heatsink compound.
That was early on, maybe heating the aluminum plate in the center is
good enough.
Cool experiment, thanks for keeping us posted.
Mikek

[Jan Panteltje]

On a sunny day (Sun, 1 Apr 2012 10:48:46 -0500) it happened "Tim Williams"
<tmor...@gmail.com> wrote in <jl9tcl$ju8$1...@dont-email.me>:

>Try a cap from op-amp output to -input, 100pF is enough. Add a series 10k
>resistor between this node (-in with cap) and the shunt resistor, so the cap
>has something to work into. Get rid of the 100k series resistor and 1uF
>filter cap.

I have tried several configurations, of course the first one that came to mind
is 'integrator' but I had problems with huge oscillation at some input voltages.
After many test I settled for this, as I cannot get it unstable in any way.
I reduced the source resistor to 1.1 Ohm (2 x 2.2 parallel) to get more
of the generated heat into the hotplate.

>As shown, it'll something between oscillate and motorboat, depending on the
>position of the planets.

The planets seemed favorable today, you will have to show the math why these
should influence - and in what way- the circuit.
I have read about dark energy, but am not that much of a believer,
especially not if it interacts with the electrons in this circuit.
Once someone told be he had a system for the stock market,
and in that system you should buy if this planet went up and the other down,
so I asked him:
Why not this planet down and the other up?
That shorted his neural net enough to drop the idea...

>The op-amp is an integrator with 90 degree phase
>shift, and the RC following it does the same (for a more limited range of
>frequencies). 180 degree phase shift at most any frequency means you're
>guaranteed to oscillate somewhere.

The 1k is just a gate resistor to stop the MOSFET from interfering with local FM
and short wave, the 100k isolates the rather low output impedance from
whatever the MOSFET wants to put out on its gate, it is basically a 2 way 'T' filter.

>You might consider making both series input resistors (the 470k control
>voltage filter and the shunt voltage feedback) the same value (100k?) so the
>input bias (if any) generates a matching offset on both inputs. As a CMOS
>amp, offset won't be the greatest (a few mV, plus input offset bias), but if
>this is within a temperature control loop, offset and 1/f noise won't be a
>problem.

The circuit is now like this:
PIC runs on 3V supply, and the PWM switches between 0 and 3V.
With an 1.1 Ohm resistor for 330 mA max (for now, based on previous plastic box
burning test) no more than 600 mV should be at the + input of the TCL274,
making 330 mV about mid range (it can become -5 °C).
This requires a voltage divider of ratio of .6 to (3 - .6) makes .6 to 2.4,
and to not load that opamp I have now 470 k to the PIC PWM output and 120 k to ground,
normal E series, high values preferred so I can use my 1 uF caps.

+4 V
R1 |
470k + |------
---===---------------|\ 100k 1k |--- |

| | | - | >-------===--------===----| |<-- === 1u

0-3V [ ] === --|/ | |---| |
PWM | | 1u | === IRLZ34N | ///
from PIC /// |C1 | | 1u on |
| 120k /// | TCL274 /// hotplate |

/// | as heater | about 300 mA
------------------------------------|
|

[ ] 1.1 Ohm
|
///
These are actually nice opamps, very low offset, typical about a mV,
I measure less, even lower offset drift, 1.8 uV (micro volt) per degree C.
And works all the way to -.2 V common mode range (but not very high upwards).
As in these one supply circuits, having the 0 V as reference is nice.
I will take some peculiarities, already I am having great fun with it.
The opamp output voltage range detoriates fast with any load (say 5 mA).

[Tim Williams]

No, like this.
http://webpages.charter.net/dawill/tmoranwms/Circuits_2010/Current_Sink.png
It is easy to show the speed, stability, accuracy and phase margin are
greatly improved. If you cannot show why this is better than the circuit
you've drawn, you shouldn't be working with op-amps at all, do it in
software.

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms

"Jan Panteltje" <pNaonSt...@yahoo.com> wrote in message

news:jlaabb$gek$1...@news.albasani.net...

[Martin Brown]

Assuming he is serious about this experiment then the least bad way to
do it would be with the core electronics inside a hefty block of
hermetically sealed aluminium heated by Raychem heating tape on the
outside and wrapped in a very thick layer of polystyrene. The aim would
be to keep it at a very steady temperature - although it might be worth
making that well below room temperature. There are published patents on
TEC designs for isotope ratio mass specs that exploit the unusually low
thermal noise characteristics of certain opamps operated at appropriate
sub-zero temperatures with 100G feedback resistors.

The electronic gain wants to be as low as possible and the optics need
considerable work to maximise signal to noise. Around 10x optical gain
is possible by non-focussing flux concentrators. It is routine in all
difficult photon detection scenarios for high energy physics where
neutrinos and other elusive particles are being sought.

You can even buy the requisite optics of the shelf from Edmunds.

I would also monitor humidity, air pressure and external temperature as
I am sure that whatever "effects" have been "measured" so far correlate
far more closely with ambient temperature than with anything else.

--
Regards,
Martin Brown

[Jan Panteltje]

On a sunny day (Sun, 1 Apr 2012 15:12:05 -0500) it happened "Tim Williams"
<tmor...@gmail.com> wrote in <jlacqc$6pj$1...@dont-email.me>:

>No, like this.
>http://webpages.charter.net/dawill/tmoranwms/Circuits_2010/Current_Sink.png

Yes Tim, but that is basically an integrator, as I mentioned.

>It is easy to show the speed, stability, accuracy and phase margin are
>greatly improved. If you cannot show why this is better than the circuit
>you've drawn, you shouldn't be working with op-amps at all, do it in
>software.

Well, a bit bold statement, you obviously did
not read about capacitive loading of opamp outputs,
to return the political statement ;-)

But anyways, I will try your negative feedback for high frequencies,
alias 'integrator', for a totally different reason:
The PWM filter, the RC combination that smoothes the PWM to DC, is not perfect.
This causes a slight RF ripple of the drive voltage on the opamp + input,
resulting in a lot of output swing in my circuit.

It is less with higher PWM frequency, but for this PIC microcomputer
a higher PWM frequency means 6 bits resolution, a medium PWM
frequency has 8 bits resolution,
and the lowest PWM frequency has 11 bits resolution, all set by the internal
PIC hardware.
So doing the integrator thing would also filter the PWM better, and quiet things
down some more.
So I will leave in the T filter, as it is proven to work,
but do a test with your circuit added, to see how it reacts to PWM ripple.
If you like <..> I can engrave your name on the alu bottom of the box if it works[1].
I bought a nice engraving tool for about 5 $ on ebay, and have played with it.
Would that heal any wounds I may have made by being not totally cooperative
in immediately agreeing and sending flowers?



>Tim

[1] Will report back.

[Jan Panteltje]

I wrote:
[1] Will report back.


+4V
|
R1 ---- |
470k + R2 | |
PWM ---===----------------|\ 100k |--- |
0-3V | | - | >---------===----| |<-- === 1u
from [ ] === ---|/ | |---| |
PIC 120k | | 1u | === IRLZ34N | ///
/// | | | C2 on |
/// | TCL274 | 1u hotplate |
| | as heater | 0-600 mA
-------------===-----------|
100k |
R3 [ ] 1.1 Ohm
| R4
///

So, I changed some components around a bit,
this seems to work OK over the full range of 0 to 600 mA.

I stayed with the standard capacitors of 1uF, and the standard resistors of 100k.
1k is OK for R2, in that the MOSFET does not detectable oscillate,
but then its 880 pF input capacitance is still felt by the opamp.
As we are slowing down things anyway, 100k is better.

What point size of engraving do you prefer?
Please note there is only 80 mm height available.
Of course we can always change to a bigger box.

[George Herold]

Hi Jan, I like the V-I converter. It gives a nice linear relation
between voltage in and power out. Do you stick the 1.1 ohm current
sesnse resistor on the hot plate too? Why not use a BJT for the pass
element?

George H.

[Jan Panteltje]

On a sunny day (Fri, 30 Mar 2012 12:30:45 -0700 (PDT)) it happened George
Herold <ghe...@teachspin.com> wrote in
<bed937c9-1a10-4c92...@db5g2000vbb.googlegroups.com>:

>> This is what we get if dark (no tritium light):
>> http://panteltje.com/pub/dark_signal_IMG_3384.JPG'
>> that is 15 mV
>>

>> And this is what we get with the tritium light:
>> http://panteltje.com/pub/tritium_signal_IMG_3388.JPG
>> 847 mV

>> 470p
>> ---||---
>> | 120M |
>> -----====-----
>> | - |
>> || ----------- |\ |
>> || | + | >------------- multi meter --
>> || --- ---|/  TCL247 |
>> || / \ BPW21 | |
>> || ---  /// ///
>> || |
>> || ///
>> The TCL247 allows you to drive the inputs below Vss

>> common mode range is to -.2 V
>>

>> So, now we know some real values, and can proceed

>I don't know the TCL427, but is the 15mV due to the input bias
>current. Does that go up with temperature?

This I still have to find out exactly,
when everything is mounted on the 'hotplate' it becomes
easier to do a temperature run.

I think it is photocell current, as it was not 'absolute dark' either.
I will store both the values from the blacked out photocell and
those from the one looking at the tritium light, so later (after one year)
different effects can be traced back, and hopefully systematic
error can be removed mathematically.
Of course there will be many test runs before gong for the very long one.. :-)

[Jan Panteltje]

On a sunny day (Mon, 2 Apr 2012 06:40:32 -0700 (PDT)) it happened George
Herold <ghe...@teachspin.com> wrote in
<e9daf0e4-451d-42cc...@12g2000vba.googlegroups.com>:

?????????????????



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[Jan Panteltje]

On a sunny day (Wed, 28 Mar 2012 10:44:20 -0700 (PDT)) it happened George
Herold <ghe...@teachspin.com> wrote in
<dbafac36-7f85-4e97...@em9g2000vbb.googlegroups.com>:

>On Mar 28, 4:45 am, Jan Panteltje <pNaonStpealm...@yahoo.com> wrote:
>> On a sunny day (Tue, 27 Mar 2012 12:54:57 -0700 (PDT)) it happened George
>> Herold <gher...@teachspin.com> wrote in
>> <3a88efe3-9b1b-404d-8de4-e0986e252...@9g2000vbq.googlegroups.com>:
>>
>> >Hey Jan,  I was thinking about you design last night.  Why the two
>> >photodiodes?  If you want the lowest leakage then don't bias the
>> >photodiode.  Just ground one side and run the other into a TIA.  You
>> >don't need any speed.  And with a grounded photodiode and no light the
>> >only offset will be from the opamp. (Vos and I-bias* R-feedback)
>>
>> >George H.
>>
>> The reason is the temperature drift of the dark current,
>
>With no voltage across the PD there is no dark current.

oops.
How about wild electrons?



>> keeping 2 photodiodes in your configuration, but connected the
>> opposite way, one in the dark, eliminates any changes in dark current
>> to a large extend.
>> At least I hope so.
>>
>> I have made 2 designs, one with TIA as you suggest,
>> I will do some measurement as soon as those diodes arrive,
>> R-feedback is very big... :-)
>
>More than one Giga ohm?

120M


>George H.
>

[JW]

On Tue, 03 Apr 2012 10:13:55 GMT Jan Panteltje <pNaonSt...@yahoo.com>
wrote in Message id: <jleih8$ff6$1...@news.albasani.net>:

>On a sunny day (Mon, 2 Apr 2012 06:40:32 -0700 (PDT)) it happened George
>Herold <ghe...@teachspin.com> wrote in
><e9daf0e4-451d-42cc...@12g2000vba.googlegroups.com>:
>
>?????????????????
>
>
>
>>T24gQXByIDIsIDY6MjOgYW0sIEphbiBQYW50ZWx0amUgPHBOYW9uU3RwZWFsbS4uLkB5YWhvby5j
>>b20+IHdyb3RlOgo+IEkgd3JvdGU6Cj4KPiBbMV0gV2lsbCByZXBvcnQgYmFjay4KPgo+IKAgoCCg
>>IKAgoCCgIKAgoCCgIKAgoCCgIKAgoCCgIKAgoCCgIKAgoCCgIKAgoCCgIKAgoCCgIKAgKzRWCj4g
>>oCCgIKAgoCCgIKAgoCCgIKAgoCCgIKAgoCCgIKAgoCCgIKAgoCCgIKAgoCCgIKAgoCCgIKAgoCCg
>>fAo+IKAgoCCgIKBSMSCgIKAgoCCgIKAgoCCgIKAgoCCgIKAgoCCgIKAgoCCgIKAgoCCgIKAgoCAt
>>LS0tIHwKPiCgIKAgoCA0NzBrIKAgoCCgIKAgoCCgIKArIKAgoCCgIKAgoCCgIFIyIKAgoCCgIKAg
>>oCB8IKAgoCB8Cj4gUFdNIC0tLT09PS0tLS0tLS0tLS0tLS0tLS18XCCgIKAgoCCgIKAxMDBrIKAg
>>oCB8LS0tIKAgoCCgfAo+IDAtM1YgoCCgIKAgfCCgIKAgfCCgIKAgoC0gfCA+LS0tLS0tLS0tPT09
>>LS0tLXwgfDwtLSCgIKAgPT09IDF1Cj4gZnJvbSCgIKAgoFsgXSCgID09PSCgIKAtLS18LyCgIKB8
>>IKAgoCCgIKAgoCCgIKB8LS0tfCCgIKAgfAo+IFBJQyCgIDEyMGsgfCCgIKAgfCAxdSCgfCCgIKAg

[snip]

[Jan Panteltje]

On a sunny day (Mon, 2 Apr 2012 06:40:32 -0700 (PDT)) it happened George
>Herold <ghe...@teachspin.com> wrote in
><e9daf0e4-451d-42cc...@12g2000vba.googlegroups.com>:
>
?????????????????
>>T24gQXByIDIsIDY6MjOgYW0sIEphbiBQYW50ZWx0amUgPHBOYW9uU3RwZWFsbS4uLkB5YWhvby5j

Never mind, need to add auto base64 codec to my newsreader one of those days..
panteltje10: ~ # base64 -d article.txt

>Hi Jan, I like the V-I converter. It gives a nice linear relation
>between voltage in and power out. Do you stick the 1.1 ohm current
>sesnse resistor on the hot plate too? Why not use a BJT for the pass
>element?

The 1.1 (actually 2 x 2.2 Ohm in parallel) is soldered directly to the source of the MOSFET
and in that way helps heat the MOSFET, and the MOSFET will heat the hotplate.
I could use a BJT, but that needs driving power.
I could get a darlington I suppose, but I have a bunch of these nice
logic level IRLZ43N (on at about 2 V Vgs), and it is easy to drive from
this CMOS opamp.
I really want to keep the currents in the 4 TCL274 as low as possible,
to avoid any cross-heating in the chip with the light and dark preamps.
So now the output current is zero, this also improves output swing for
this opamp.
I am now working on the power supply with battery backup, so far the most difficult thing!

[Jan Panteltje]

On a sunny day (Tue, 03 Apr 2012 06:33:58 -0400) it happened JW
<no...@dev.null> wrote in <1dkln7lvqd5jtu6f4...@4ax.com>:

>George posted in Base64 for some reason. Here's what it says:ogram

OK, got it, and decoded it with the 'base64' program in Linux.
There is a content header that maybe I should one day have my
newsreader parse...

Thanks!

[Jan Panteltje]

On a sunny day (Tue, 03 Apr 2012 10:46:27 GMT) it happened Jan Panteltje
<pNaonSt...@yahoo.com> wrote in <jleke6$jfs$1...@news.albasani.net>:

>I could get a darlington I suppose, but I have a bunch of these nice

>logic level IRLZ43NZ

oops, IRLZ34N

[George Herold]

On Apr 3, 6:13 am, Jan Panteltje <pNaonStpealm...@yahoo.com> wrote:
> On a sunny day (Fri, 30 Mar 2012 12:30:45 -0700 (PDT)) it happened George

> Herold <gher...@teachspin.com> wrote in
> <bed937c9-1a10-4c92-b34a-4f2531a35...@db5g2000vbb.googlegroups.com>:

> Of course there will be many test runs before gong for the very long one.. :-)- Hide quoted text -

>
> - Show quoted text -

I can't find the TCL247 anywhere.. can't you look up the bias current
on the spec sheet?

Hey I had an idea the other day. How about if you run two photodiode
circuits one illuminated by the tritium lamp and the other from a
lightbulb or LED. That might help take care of weird drifts that you
haven't thought of. (Mind you I think the best you can expect is a
null result.. but so what!)

George H.

[George Herold]

On Apr 3, 6:51 am, Jan Panteltje <pNaonStpealm...@yahoo.com> wrote:
> On a sunny day (Tue, 03 Apr 2012 10:46:27 GMT) it happened Jan Panteltje

> <pNaonStpealm...@yahoo.com> wrote in <jleke6$jf...@news.albasani.net>:

[George Herold]

On Apr 3, 6:13 am, Jan Panteltje <pNaonStpealm...@yahoo.com> wrote:
> On a sunny day (Mon, 2 Apr 2012 06:40:32 -0700 (PDT)) it happened George

> Herold <gher...@teachspin.com> wrote in
> <e9daf0e4-451d-42cc-ae04-5c661abb4...@12g2000vba.googlegroups.com>:
>
> ?????????????????
>
>
>
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> >IEgu- Hide quoted text -

>
> - Show quoted text -

WTF is that? Did I do that... sorry.

George H.

[Jan Panteltje]

On a sunny day (Tue, 3 Apr 2012 06:15:58 -0700 (PDT)) it happened George
Herold <ghe...@teachspin.com> wrote in
<99b14aee-c9f5-422a...@do6g2000vbb.googlegroups.com>:

>I can't find the TCL247 anywhere.. can't you look up the bias current
>on the spec sheet?

That is because it is TLC274...
For the input bias current only a typical value is given at 25 C: .7 pA.
And at 70 C typical 50 pA and maximum 300 pA.
So there is a huge spread from one chip to the other,
and a huge dependence on temperature.
Comparing 2 channels on the same chip in changing conditions may
help eliminate any observed unexpected effects.
For the photo diodes the story is very similar.

>Hey I had an idea the other day. How about if you run two photodiode
>circuits one illuminated by the tritium lamp and the other from a
>lightbulb or LED. That might help take care of weird drifts that you
>haven't thought of. (Mind you I think the best you can expect is a
>null result.. but so what!)

So how do you know LED does not age in one year?



>George H.

[josephkk]

They do. How they age depends a lot on what the construction is. Whites
(phosphor based) age the most by far. Other colors (peak lambdas) age
differently.

YCLIU

?-)