Question on haze around nixie digit
Dylan Distasio
Dylan
JohnK
----- Original Message -----From: Dylan DistasioSent: Thursday, February 16, 2012 11:36 AMSubject: [neonixie-l] Question on haze around nixie digitHi all-Just wanted to tap the brains of the nixie experts on the list. A while ago, I bought one of these contraptions on eBay to turn into a clock http://tinyurl.com/78r73x8I finally got around to wiring up the connectors last night. The unit consists of 6 separate modules, each with their own 74141 chip and anode resistor. I'm not sure of the R1 value offhand.
...clip....
David Forbes
> Hi all-
>
> I am using a 50mA PS for the HV piece. Anyways, everything is working
> great but I notice what I would describe as a kind of light haze around
> the digits. The digit itself doesn't look like it is flickering but the
> haze looks like it is. I've tried two out of the 6 nixies so far (these
> are IN-14s) with the same results. I'm just wondering if anyone has
> seen this before and if it is anything to worry about.
>
> Thanks,
> Dylan
>
Dylan,
That is normal for most Nixie tubes, except the early styles. The haze
is caused by the mercury in the tube, which was placed in there to make
the cathodes last a long long time. Ionized mercury is violet, among
other colors.
--
David Forbes, Tucson AZ
Dieter Waechter
and the mercury inside the tube.
You may find out from the spectrum (in some cases) what mixture is in the
tube.
Second, the lower the Ucc (cold cathode voltage) the higher the haze. And
the more blurred the glow.
IN extreme cases (Ucc too low) the haze become ghost spots in the tube
(known as the blue spot problem at IN-18 tubes)
To get a high definition readout, ot the best you can get out of the tube,
drive it without Ucc in direct drive.
Dieter
Dylan Distasio
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jb-electronics
here a broken GR-414 in a 2%Ar98%Ne mixture @ 300V:
http://www.nixie.jb-electronics.de/img/2012-01-24/glow_2.jpg
Jens
Cobra007
> To get a high definition readout, ot the best you can get out of the tube,
> drive it without Ucc in direct drive.
> Dieter
direct drive and now you say you get the best results without direct
drive. Am I missing something?
Michel
Dieter Waechter
What I mean is: To get a high definition readout and the best you can
get out of the tube, drive it without Ucc AND drive it with direct drive.
Cobra007
Michel
Lucky
but seemed relevant and I think Dylan has been answered.
Regarding blue spots: I am of the understanding that if you drive a
nixie with too low a Ucc that a blue stop may appear (although still
do not understand why?) I was testing some Mullard ZM1177's the other
day with a jury rigged hv supply on a breadboard with an appropriate
anode resistor, as I tested the 3rd one a blue spot appeared in it,
same with next, quite bright too. I then realised I had connected the
tube reverse polarity ie neg to anode (teach me to use same coloured
jumper wires). Reconnecting anode to pos and all is well.
My question: Why does the blue spot appear with the polarity reversed
and I didn't think a nixie would light (properly) in such conditions.
Would be grateful if someone could steer me in the right direction.
Dave.
Frank Bemelman
Cheers, Frank
-----Oorspronkelijk bericht-----
From: Dieter Waechter
Sent: Thursday, February 16, 2012 5:42 AM
To: neoni...@googlegroups.com
Subject: Re: [neonixie-l] Question on haze around nixie digit
--
William Lee
Frank Bemelman
Lucky
| | |
Dieter for first stating 'Ucc' (I think maybe we are talking Vcc?) Regardless Ucc had been taken to mean something "cold cathode voltage" Have you not bothered to read the entire thread?
Me for repeating the same (or maybe just being naive)
Or 3 useless replies 2 of which are sarcastic, and one mocking the 'Invention' word which I thought we had finished with!
Do you not wish to help anyone out? Do you not have anything to add, informational or knowledgeable wise? If not why answer? Just to mock? And I notice you did not jump all over Deiter when he said "Second, the lower the Ucc (cold cathode voltage) the higher the haze"
Talk about childish! Sorry I posted.
Frank Bemelman
You received this message because you are subscribed to the Google Groups "neonixie-l" group.
Frank Bemelman
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Dieter Waechter
> Cheers, Frank
Hi Frank,
yes.
Dieter
John Rehwinkel
Pretty much any microprocessor can do the job (okay, an 1802 wouldn't be able to do a lot in realtime). There are several that have enough I/O pins to do the job (with level shifters). Normally I'd just use a smaller one and some shift register chips. You can use level shifters on the shift register outputs, or use shift register chips with high voltage outputs.
> On a completely different topic, does anyone have any interesting books they would recommend on any topic related to nixies, decatrons, or old school logic chips? I have been on an interlibrary loan kick to find some of the ones I can't find used or cheap. I just got Cold Cathode Glow Discharge Tubes that way, and am looking for other suggestions that might be worth tracking down.
For old school logic, I'm very fond of Don Lancaster's "TTL Cookbook" and "CMOS Cookbook". They were both printed in large quantities, and not hard to find today. In fact, one member here has been known to give away copies of these when he had surplus. For display technology, there are a lot of good ones out there (many available online too).
I happened to pick up a copy of this one in a used book store a while back. It covers a bunch of different technology, but not in a whole lot of depth:
"Electronic Displays", Bylander, Texas Instruments, 1979 (ISBN: 0-07-009510-8)
I'm also just going to quote Tim Laing's description of his nixie library verbatim, as it gives a lot of good starting points for library searches:
> These are the books in my Nixie Library. Some are pretty technical. More
> technical than I am!
>
> Cold Cathode DIscharge Tubes J.R. Acton, J.D. Swift 1963. Academic Press
> Inc Publishers New York ( No Library Of congress Numbers) Very deep waters
> a lot of theory and math.
>
> Cold Cathode Glow Discharge Tubes Weston 1968 Iliffe Books Ltd London( No
> Library Of congress Numbers) More practical material on construction and
> materials. Still a lot of theory and math. But a technical layman can
> learn a lot from this book.
>
> Electronic Counting Circuits J.B. Dance 1967 Library of Congress Catalog
> Card system 67-13048 Iliffe Books Ltd London Practical Circuits Bible.
> With descriptions of opertation of all the different types of counters and
> indicators. Nixies, trigger tubes, dekatrons, E1T
>
> Cold Cathode Tubes J.B. Dance 1967 Iliffe Books London( No Library Of
> congress Numbers) Descriptions of the different types of cold cathode
> tubes and basic circuits.
>
> Applications of Neon Lamps and Gas Dischage Tubes, Edward Bauman Vice
> president, Signalite Incorported. 1966 Carlton Press New York Library of
> congress card number 66-28779 1001 uses for neon lamps/diodes showing
> signalites products.
>
> Using and Understanding Miniature Neon Lamps by William G Miller 1969
> Howard W. Sams Lib Congress Cat 69-16778 General book for
> nonmathematical electonic persons. Practical applications and circuits
> using neon lamps.
>
> I would say Weston to get a good grasp on what you need to build nixies.
> Acton If you want to get your Phd!
> Tim Laing
- John
Dieter Waechter
Ucc = Ukk = Voc = Uclamp = cold cathode voltage = off cathode voltage (kk =
kalte kathode (German)).
The voltage measured from GND to the switched off cathodes.
At dircet drive, the Ukk is equal to Ua (Ua = Va = Up = Vp = Anode voltage =
Supply voltage = Plate voltage)
Dieter
Dieter Waechter
;-)
No problem, I'm far above any childish comments. I forgot the "U" is not so
well known at Neonixie.
U = the formula symbol according to DIN 1304 for the Voltage.
Dieter
David Forbes
> I forgot the "U" is not so well known at Neonixie.
> U = the formula symbol according to DIN 1304 for the Voltage.
> Dieter
I only know that U means voltage because I work on a fine German telescope.
John Rehwinkel
I had remembered that U was used for voltage in Europe (and B in Russia), but I was a little confused by "cold cathode", as all nixie cathodes are cold. I had surmised that it was "off cathode", but I appreciate the clarification.
> The voltage measured from GND to the switched off cathodes.
> At dircet drive, the Ukk is equal to Ua (Ua = Va = Up = Vp = Anode voltage = Supply voltage = Plate voltage)
Not necessarily - if you're direct driving them with 74141 chips, Ucc would be about 60 volts, and with K155ID1 chips, about 100 volts. Aside from those, yes, the off cathodes would be allowed by most drivers to "float", and they'd tend to float to the anode voltage (which isn't always the supply voltage, but the maintaining voltage if another cathode is lit and there is an anode resistor). I realize that's pretty pedantic of me, but it's easy to get confused about what your circuit is actually doing unless you're aware of these various effects.
- John
Dieter Waechter
> At dircet drive, the Ukk is equal to Ua (Ua = Va = Up = Vp = Anode voltage
> = Supply voltage = Plate voltage)
> Not necessarily - if you're direct driving them with 74141 chips, Ucc
> would be about 60 volts, and with K155ID1 chips, about 100 volts. Aside
> from those, yes, the off cathodes would be allowed by most drivers to
> "float", and they'd tend to float to the anode voltage (which isn't always
> the supply voltage, but the maintaining voltage if another cathode is lit
> and there is an anode resistor). I realize that's pretty pedantic of me,
> but it's easy to get confused about what your circuit is actually doing
> unless you're aware of these various effects.
Oh yes John, thanks for that comment.
You are right of course.
I must clarify again:
(note that this is my own "language" ;-) - For the ones who don't like it -
please tell me how you would name it, or ignore it)
a) When I speak of "direct drive" I always mean 1 high voltage transistor
for each cathode, without any Zener diodes.
b) When I speak of "clamped direct drive" I mean 1 low voltage transistor
for each cathode, with Zener diodes for clamping. (74141 ect.)
c) When I speak of "multiplex drive" I mean 1 high voltage transistor for
each cathode group, without any Zener diodes, multiplexed
d) When I speak of "clamped multiplex drive" I mean 1 low voltage transistor
for each cathode group, with Zener diodes for clamping, multiplexed (74141
multiplexed for example - the worst drive ever)
Note that this is all not valid for biquinary Nixie tubes of course, but for
standard nixie tubes
Dieter
Lucky
for voltage, but never thought about it. I suppose being from the UK
that I see Volts written as U quite often so never questioned it nor
knew those over the water are not familiar. Did get me thinking
though, where does the 'U' originate, closest I can find is that U is
for Unterschied, which in German means "difference" (as in potential
difference). Is that the correct translation? Vorsprung durch Technik
indeed!
But when we started using it I have no idea. One day we were all using
the standard 'V' then suddenly 'U' crept in and made it's self at
home! Of course we also use 'U' to mean the standard 19" or 23" rack
mount unit. 1U=1-3/4". Maybe it has more uses than those?
"And it won’t stop folks from inventing either. " Thank goodness for
that, the more inventions the better IMHO.
Now, can anyone answer my question as to why the nixies showed a
bright blue spot when I reversed the polarity, what is happening to
cause it?
JohnK
Frank Bemelman
jb-electronics
as Dieter pointed out, the blue- or purple-ish haze comes from other gases or substances in your Nixie tube. Neon glows red / orange, depending on pressure and voltage. The little Argon in there makes it almost completely orange / yellow.
But there are other substances in the tube, like mercury, that is used to prolong the cathodes' lives. Mercury has a strong ultra-violet component, but also some visible parts in blue / green. (This is why you can only get red or blue/greenish genuine "Neon" tubes, almost all other colors are created using some fluorescence effect).
When you inverse polarity, nothing actually happens, except that the electric field changes its direction inside the tube. This, however, results in the electrons leaving the anode mesh and then moving towards the cathode. Electrons are not heavy, and so they are able to excite a gas atom to glow after a "flight" of only a few mm. They need a kinetic energy of something in the order of eV, and with 150V accelerating them (thus an electric field of 150V / cm) 1mm is enough.
OK, why is this important? In most Nixie tubes so-called getter materials are used. These are usually barium based chemicals who adsorb non-inert gas molecules (residuals of oxygen, nitrogen, or other impurities). These getters are usually mounted on the anode, because during normal operation, there are practically no electrons there, only the positive gas ions.
When driving the Nixie tube inversed, the electrons can excite the getter material. This has a whole other spectrum than the gas, so it creates all kind of funny lights. That is not good for the tube, though, because you might sputter the getter material with that, just like with the cathodes in normal drive. And in that case, mercury might not even help preventing it (I don't know for sure).
Hope that makes sense :-)
Jens
IMO, Ucc is a rather odd term. That�s what triggered my first reply.Suppose we started to use �Siemens� again. Or express capacitance
in square meters. I had an old teacher once, who named every
power supply with PSA. That stood for �Plaat Spannings Apparaat�,
which is dutch for Plate Voltage Apparatus. As if the power supplywas only suitable to power tubes with anodes and plates.Cheers, Frank
��
From: JohnKSent: Friday, February 17, 2012 4:06 AMSubject: Re: [neonixie-l] Question on haze around nixie digit
�
Ucc is a common term for supply voltage [Google it]. The 'cc' is probably questionable in this case, but the U is common in Europe.
�
Semi-related Factoid:- If you read early US books on wireless you will find the term "anode" used in a sentence when they mean the supply voltage for the tubes. Makes for strange reading today. eg, "..remove the anode if the temperature exceeds..."
�Maybe my post is� one Lucky is having a crap-attack about. Well, I actually asked the colour of the haze so I could repeat answers given over the years !� Jimi always got a mention if it was purple. And as for 'invention' - you will never hear the end of that one. And because you thought it was finished with I am not allowed to comment - oh deary me.�jk
----- Original Message -----From: Frank BemelmanSent: Friday, February 17, 2012 1:10 AMSubject: Re: [neonixie-l] Question on haze around nixie digit�
So, is �invention� now a forbidden word?Sheesh...
�Yes I read everything. Dieter is NOT very helpful if he invents �new� names for things.I can not recall someone using the �Ucc� ever being used in this and previous Neonixienewsgroup.�
I am sorry you posted too.
�But hey, it happens.�
Learn to smile
��
From: LuckySent: Thursday, February 16, 2012 3:31 PMSubject: Re: [neonixie-l] Question on haze around nixie digit
�
Don't know who is worse here.
Dieter for first stating 'Ucc' (I think maybe we are talking Vcc?) Regardless Ucc had been taken to mean something "cold cathode voltage" Have you not bothered to read the entire thread?
Me for repeating the same (or maybe just being naive)
Or 3 useless replies 2 of which are sarcastic, and one mocking the 'Invention' word which I thought we had finished with!
Do you not wish to help anyone out? Do you not have anything to add, informational or knowledgeable wise? If not why answer? Just to mock? And I notice you did not jump all over Deiter when he said "Second, the lower the Ucc (cold cathode voltage) the higher the haze"
Talk about childish! Sorry I posted.
Post
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dr pepper
for this device.
I like the microchip pic range of micro's, a pic 16f876 would be
something I'd be looking at, or maybe a pic16f88 and multiplex the
outputs to the decoders, I cant remember if 141's have an enable input
or not, if not you might be able to power the chip up and down with a
transistor and use that as an enable, but test it first.
On 17 Feb, 03:06, "JohnK" <yend...@internode.on.net> wrote:
> Ucc is a common term for supply voltage [Google it]. The 'cc' is probably questionable in this case, but the U is common in Europe.
>
> Semi-related Factoid:- If you read early US books on wireless you will find the term "anode" used in a sentence when they mean the supply voltage for the tubes. Makes for strange reading today. eg, "..remove the anode if the temperature exceeds..."
>
> Maybe my post is one Lucky is having a crap-attack about. Well, I actually asked the colour of the haze so I could repeat answers given over the years ! Jimi always got a mention if it was purple. And as for 'invention' - you will never hear the end of that one. And because you thought it was finished with I am not allowed to comment - oh deary me.
>
> jk
>
>
>
> ----- Original Message -----
> From: Frank Bemelman
> To: neoni...@googlegroups.com
> Sent: Friday, February 17, 2012 1:10 AM
> Subject: Re: [neonixie-l] Question on haze around nixie digit
>
> So, is “invention” now a forbidden word?
> Sheesh...
>
> Yes I read everything. Dieter is NOT very helpful if he invents ‘new’ names for things.
> I can not recall someone using the “Ucc” ever being used in this and previous Neonixie
> newsgroup.
>
> I am sorry you posted too.
>
> But hey, it happens.
>
> Learn to smile
>
> Sent: Thursday, February 16, 2012 3:31 PM
> To: neoni...@googlegroups.com
> Subject: Re: [neonixie-l] Question on haze around nixie digit
>
> Don't know who is worse here.
> Dieter for first stating 'Ucc' (I think maybe we are talking Vcc?) Regardless Ucc had been taken to mean something "cold cathode voltage" Have you not bothered to read the entire thread?
> Me for repeating the same (or maybe just being naive)
> Or 3 useless replies 2 of which are sarcastic, and one mocking the 'Invention' word which I thought we had finished with!
>
> Do you not wish to help anyone out? Do you not have anything to add, informational or knowledgeable wise? If not why answer? Just to mock? And I notice you did not jump all over Deiter when he said "Second, the lower the Ucc (cold cathode voltage) the higher the haze"
> Talk about childish! Sorry I posted.
>
> Post
>
>
>
> 1KViewDownload- Hide quoted text -
>
> - Show quoted text -
MrNixie (UK)
touched on in this thread - does anyone have an explanation for the
**physics** of what is going on inside the tube, particularly in
relation to the ethereal blue spots? Personally - I find them quite
intriguing - particularly the large ones that appear in IN18's when
the "1" cathode is lit. If people ask, I just claim they are angels...
well it usually shut folk up for a few minutes...
jb-electronics
I wrote something about it a day ago, where is the point you would like
to go deeper?
Jens
Mich...@aol.com
marcin
few month ago after two years of spotless work. But i has it only
during darkness! In daylight it is OK.
On 18 Feb, 16:45, Micha...@aol.com wrote:
> Lots of theories as to the blue dots.....
Imbanon
supply voltage', or at least something like that. We have been that
acronym on college, but I don't know what it stands for. I live in
Europe.
On Feb 17, 4:06 am, "JohnK" <yend...@internode.on.net> wrote:
> Ucc is a common term for supply voltage [Google it]. The 'cc' is probably questionable in this case, but the U is common in Europe.
>
> Semi-related Factoid:- If you read early US books on wireless you will find the term "anode" used in a sentence when they mean the supply voltage for the tubes. Makes for strange reading today. eg, "..remove the anode if the temperature exceeds..."
>
> Maybe my post is one Lucky is having a crap-attack about. Well, I actually asked the colour of the haze so I could repeat answers given over the years ! Jimi always got a mention if it was purple. And as for 'invention' - you will never hear the end of that one. And because you thought it was finished with I am not allowed to comment - oh deary me.
>
> jk
>
>
>
>
>
>
>
> ----- Original Message -----
> From: Frank Bemelman
> To: neoni...@googlegroups.com
> Sent: Friday, February 17, 2012 1:10 AM
> Subject: Re: [neonixie-l] Question on haze around nixie digit
>
> So, is “invention” now a forbidden word?
> Sheesh...
>
> Yes I read everything. Dieter is NOT very helpful if he invents ‘new’ names for things.
> I can not recall someone using the “Ucc” ever being used in this and previous Neonixie
> newsgroup.
>
> I am sorry you posted too.
>
> But hey, it happens.
>
> Learn to smile
>
> Sent: Thursday, February 16, 2012 3:31 PM
> To: neoni...@googlegroups.com
> Subject: Re: [neonixie-l] Question on haze around nixie digit
>
> Don't know who is worse here.
> Dieter for first stating 'Ucc' (I think maybe we are talking Vcc?) Regardless Ucc had been taken to mean something "cold cathode voltage" Have you not bothered to read the entire thread?
> Me for repeating the same (or maybe just being naive)
> Or 3 useless replies 2 of which are sarcastic, and one mocking the 'Invention' word which I thought we had finished with!
>
> Do you not wish to help anyone out? Do you not have anything to add, informational or knowledgeable wise? If not why answer? Just to mock? And I notice you did not jump all over Deiter when he said "Second, the lower the Ucc (cold cathode voltage) the higher the haze"
> Talk about childish! Sorry I posted.
>
> Post
>
>
>
> 1KViewDownload
Imbanon
*we'we been using that acronym