A project log for SPDT16: 16-bits arithmetic unit with relays

Let's imagine I could get about 200 SPDT relays. Of course I would know what to do with them :-D But will 200 be enough ?

Yann Guidon / YGDESYann Guidon / YGDES 04/17/2016 at 22:037 Comments

So in the spirit of the precedent log, I found tiny incandescent lamps that just fit the bill. Rated at 3V/50mA, I have a set of 50×red, 50×blue and 50×orange and I think they fit nicely with the theme of the project (power hungry). Imagine 16 or 32 of these, blinking as computations progress:

Of course I've thought about using LEDs. But these are fragile semiconductors that won't like the repeated spikes on the power supplies, even though I can add a resistor in series and a capacitor in parallel. That's quite a lot of parts. However a 60 Ohms load across the coil will help absorb the spikes.

Now I have one color for the 32 (48?) input bits, another for the (intermediary) results and another for the control signals.

To hell with saving power. I'm not building a Bomb/Colossus...

PS: Glühbirnchen is the german word for "tiny glowing bulbs". I hope you learned something today :-D


Andrew Starr wrote 04/19/2016 at 08:28 point

BTW Yann, I may not be commenting a lot (T-1 doesn't leave me time for that) - but I am watching with approval :)

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Yann Guidon / YGDES wrote 04/19/2016 at 13:36 point

I noticed ! Thank you :-) And good luck with T-1 !

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Andrew Starr wrote 04/19/2016 at 08:27 point

Hey, these bulbs would be perfect for the operator panel of the T-1 :)

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Yann Guidon / YGDES wrote 04/19/2016 at 13:35 point

If I see more of them, I'll tell you where to find them :-)

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matseng wrote 04/19/2016 at 14:24 point

They are commonly named "grain of wheat bulbs" or "grain of rice bulbs" on ebay. I recently bought some big bags of these with a few different sizes and voltages. But I only got the plain vanilla "white" models. There are also small transparent colored plastic caps to make them colored as well.

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Yann Guidon / YGDES wrote 04/19/2016 at 18:09 point

Thanks for the tip :-)

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matseng wrote 04/20/2016 at 02:00 point

Since the bulbs are rather low powered and thusly would not be too hot when lit maybe the "stained glass" paints that can be bought in art supply shops could be used to color plain bulbs easily by just dipping them in (diluted?) paint.  I think the wife already got some of those pains in her art-stash.  I have to try this when I get the chance next time....

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