Jumbotron Boards

[Alec Wright]

Anyone have any objection to me ebaying the rest of the jumbotron
related boards? The ones with the optoisolators and transistor arrays
etc? We've farmed enough components from them to last us till the end of
time and still have 5 boxes left. We could sell them as "Circuit boards
with ICs xxyy on" - collection only since theyre probably not worth
posting. Otherwise i recommend they be binned.

[Sci]

In-house sale/offers first? In case someone wants to keep their own
private stash too?

[Alec Wright]

Very well. If anyone wants one, help yourself and stick a donation in
the box.

[Sci]

Fiver a board, or more? What's a reasonable donation so the space
doesn't loose out?

[Sci]

By that I mean loose out on whatever they might fetch on ebay.

[Robert Leverington]

If you want one, I don't see any problem with just taking one of the
boards for free.

FWIW we only have the boards with MOC3041 ICs left (all of the ones with
shift registers have been stripped), they also have TRIACs on but I've
so far been unsuccessful in desoldering them and unless someone is more
so it's probably not economical to try and remove them. Each board has
64 of each, and I've put 500 of the MOCs in a tray in the components
draws - we probably don't need any more than this.

I also intend[ed] to strip the kettle plugs and leads off all the boards
we have left, I've done this for all the boards that have had their ICs
stripped so far.

Robert

[Sci]

I've got a 140watt soldering gun that should get the TRIACs off. Could
someone stick a couple of MOC3041/TRIAC boards in my box? I'll stick
some money in the donation tin when I'm next in.

~ Sci

[Alec Wright]

On Fri, 2011-08-05 at 21:24 +0100, Sci wrote:
> I've got a 140watt soldering gun that should get the TRIACs off. Could
> someone stick a couple of MOC3041/TRIAC boards in my box? I'll stick
> some money in the donation tin when I'm next in.
>
> ~ Sci

I've put 4 in the box labelled "Sci's Box"

[Sci]

Cheers!

[Sci]

On 05/08/2011 21:31, Alec Wright wrote:

Collected them, thankyou, and stuck a tenner in the donations box.

Was surprised when I looked at the datasheet for the TRIACs. 8Amps at
600volts?? Okay, so that's peak for a 3-phase line, right? So that's
3.6Kw?? Or about 2Kw at mains voltage?

Am I missing something here, or missed something on the datasheet? I
can't see why other members haven't falling over each-other to use these
in home-automation tasks!

~ Sci

[Nigel Worsley]

> Was surprised when I looked at the datasheet for the TRIACs. 8Amps at
> 600volts?? Okay, so that's peak for a 3-phase line, right?

Amps is amps, 3 phase has nothing to do with it. That will usuallly be specified as 8 amps RMS but the voltage drop across a triac
doesn't vary
much with current so that is prety much the same as the average current.

> So that's 3.6Kw??

If used phase to phase then theoretically yes.

> Or about 2Kw at mains voltage?

Yep, but it will dissipate about 15W so make sure it has a decent heatsink.

> Am I missing something here, or missed something on the datasheet?

Don't know, what is the part number?

> I can't see why other members haven't falling over each-other to use these
> in home-automation tasks!

Many people are scared off by mains voltage stuff, but with a bit of care it is perfectly safe. The best advice I would give
is DON'T USE STRIPBOARD!!! If you really have to then completely remove all the copper from a strip between the
mains and low voltage circuits to give the required safety clearance. Spreading the MT1 and MT2 terminals of the triac
across 0.2" allows the same to be done on the mains side which is a very good idea.

If anyone wants more detailed advice about the safe hacking of mains circuits then feel free to ask, I do this sort of stuff
for the day job with more volts and a LOT more current.

Nigle

[M]

I'm interested to hear more Nigle, I want to learn enough to play with
home automation.

--
>
++++++++++[>+>+++>++
+++++>++++++++++<<<<
-]>>>+++++++.>++++++
+++++.+++..---------
.++++++++++.<<+++.<.

[Sci]

On 16/08/2011 00:32, Nigel Worsley wrote:
>> Was surprised when I looked at the datasheet for the TRIACs. 8Amps at
>> 600volts?? Okay, so that's peak for a 3-phase line, right?
>
> Amps is amps, 3 phase has nothing to do with it. That will usuallly be
> specified as 8 amps RMS but the voltage drop across a triac doesn't vary
> much with current so that is prety much the same as the average current.
>
>> So that's 3.6Kw??
>
> If used phase to phase then theoretically yes.
>
>> Or about 2Kw at mains voltage?
>
> Yep, but it will dissipate about 15W so make sure it has a decent heatsink.
>
>> Am I missing something here, or missed something on the datasheet?
>
> Don't know, what is the part number?

Ummm, will check! Sure they'd be mentioned on the list, but downloaded
the datasheet on the workshop machine, not this one.

>> I can't see why other members haven't falling over each-other to use
>> these
>> in home-automation tasks!
>
> Many people are scared off by mains voltage stuff, but with a bit of
> care it is perfectly safe. The best advice I would give
> is DON'T USE STRIPBOARD!!! If you really have to then completely remove
> all the copper from a strip between the
> mains and low voltage circuits to give the required safety clearance.
> Spreading the MT1 and MT2 terminals of the triac
> across 0.2" allows the same to be done on the mains side which is a very
> good idea.
>
> If anyone wants more detailed advice about the safe hacking of mains
> circuits then feel free to ask, I do this sort of stuff
> for the day job with more volts and a LOT more current.
>
> Nigle

Well I have a good practical project lined up as a trail run. I need to
control an anti-condensation panel heater. That's only 80Watts.
Intending to use a microcontroller to control it and a circulating fan
based on temperature differential between two sensors. If the
differential's too great, the fan comes on to circulate the air. If it's
too cold, the heater comes on.

Any advice on different implementation with inductive vs resistive loads?

~ Sci

[Martin Klang]

On 22 Aug 2011, at 00:56, Sci wrote:

> On 16/08/2011 00:32, Nigel Worsley wrote:

>> Don't know, what is the part number?
>
> Ummm, will check! Sure they'd be mentioned on the list, but downloaded
> the datasheet on the workshop machine, not this one.

parts from light control boards donated to hackspace:
SN75176B Differential bus transceivers
HCF4016BE Quad bilateral switch
MM74C902N Inverter hex 1-input 14DIP
HCF40106BE Hex Schmitt trigger 4000 CMOS, 40106, DIP14
HCF4094BE 8-stage shift-and-store bus register with 3-state outputs
HCF4515BE 4-bit latch/4-to-16 line decoder
M74HC573B1 Octal D-type latch with 3 state output non inverting
D8749H HMOS-E SINGLE-COMPONENT 8-BIT MICROCONTROLLER U2180569
BTA08 Snubberless, logic level and standard 8 A Triacs
MOC3041 Zero Crossing Triac Driver Output Optocoupler

/m