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LAN_403

Zum Beispiel

Mon May 18 2009, 10:26PM

Registered Member #514 Joined: Sun Feb 11 2007, 12:27AM
Location: Somewhere in Pirkanmaa, Finland
Posts: 295

And now for something utterly pointless:

1242684100 514 FT1630 Etupaneeli

At work we had to tear apart a nice big Trane water cooler (200kW+) and I, of course, took everything I could pry off with me. I ended up with a load of nice goodies from it, but the control box for the condenser coil's fans turned out to be the most interesting find. See, it had a boatload of Danfoss CI9 contactors (several kW of power handling, 4kW I think, 3 phase), that were in good condition. I was going to put them all on a shelf for later use, when I remembered a thread on the old (err... older) 4HV forum, where old relay based computers were discussed. Well, seeing how I had got a bucketload of (rather huge) relays, I had to try something myself. A bit of googling brought me to this page, and well, it was all downhill from there, really.

It's pretty much a blatant rip-off of the schematic on that site, but the high power contactors give it a nice little 'earth-quaky' twist

The only major difference is that it doesn't have any memory as such, since I didn't have enough relays. But the input switches do the same job (less complex, but not as fun). You flip the switches to the desired binary values and throw the read/write switch, and it spits out an answer (the correct one, I might add). No solid state parts, even the indicator lights are real light bulbs. Logic 1 is 230VAC (phase), 0 is 0VAC (neutral).

This thing ended up costing next to nothing at all, as the relays, or contactors, switches and indicator lights all came from the control box. The front panel was made from some piece of metal that had been lying around for way too long, and the frame didn't cost much either. Hell, even all the wires were salvaged from the control box, which is a good thing, as there are a lot of them. The only major cost of the project were the auxiliary contacts, but even those I got for something like an â‚¬ a pop from a good electrician friend of mine.

So, here is how I spent a weekend of my life, working on something completely pointless, that just ended up wasting a ton of space (but hey, isn't that what 99% of the projects on here are like?). I named it KYY-1, after the venomous snake (kyy = an adder, ain't I clever).

Here's a view of the contactors:
1242684100 514 FT1630 Kontit

And here's a look at the back of the front panel:
1242684100 514 FT1630 Paneelin Piuhat

Somehow I'm unable to take a decent picture...

Z28Fistergod

Tue May 19 2009, 02:18AM

Registered Member #2040 Joined: Fri Mar 20 2009, 10:13PM
Location: Fairfax VA
Posts: 180

I like it! I always wanted to do something like that.

Myke

Tue May 19 2009, 02:33AM

Registered Member #540 Joined: Mon Feb 19 2007, 07:49PM
Location: MIT
Posts: 969

Ooo. Very nice. I always have liked relay logic. I wanted to build a relay computer that does simple arithmetic but I can't seem to find decent relays under $1.
Make it so it has memory and can switch between addition and subtraction. :P

Solidacid

Tue May 19 2009, 06:56AM

Registered Member #1430 Joined: Sun Apr 06 2008, 11:12AM
Location: Ã…rhus, Denmark
Posts: 102

Awesome!, now add some more relays and a screen and make it do 3D graphics

Vegemeister

Tue May 19 2009, 07:05AM

Registered Member #2027 Joined: Mon Mar 16 2009, 07:34AM
Location: Texas
Posts: 5

How about reed switches? They're cheap, and they're very fast compared to most mechanical switches.

Firnagzen

Tue May 19 2009, 10:30AM

Registered Member #567 Joined: Tue Mar 06 2007, 10:55AM
Location: Singapore
Posts: 147

Record us a sound file of it working, please?

Even better: add middling sized capacitors between each wire and the ground so that you add a bit of delay between each 'clunk' of the relays switching.

uzzors2k

Tue May 19 2009, 11:04AM

Registered Member #95 Joined: Thu Feb 09 2006, 04:57PM
Location: Norway
Posts: 1308

+1 Geek Cred.

Proud Mary

Tue May 19 2009, 01:08PM

Registered Member #543 Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992

Golly gosh, what a well-made piece of work!

I would suggest vacuum relays, but even the CCCP ones are FIM 136 each, but less for quantity.

Let me know if you are interested.

Bjørn

Tue May 19 2009, 01:12PM

Registered Member #27 Joined: Fri Feb 03 2006, 02:20AM
Location: Hyperborea
Posts: 2058

Make it so it has memory and can switch between addition and subtraction.

You stumbled into the main point, the problem with simple computers is always the memory. The CPU itself can always be made so simple that the memory is 99% or more of the work. A turing complete computer can be made out of a handful of relays/logic gates/transistors, but useful memory will need thousands. My solution is to use dynamic memory and capacitors as the memory elements.

How about reed switches? They're cheap, and they're very fast compared to most mechanical switches.

I have done experiments with that too and I think it is possible to make a computer with a clock in the kHz range. The main problem I had was that they seemed to have a lot of bouncing that will make things a bit more complicated.

Dr. Dark Current

Tue May 19 2009, 06:25PM

Registered Member #152 Joined: Sun Feb 12 2006, 03:36PM
Location: Czech Rep.
Posts: 3384

BjÃ¸rn wrote ...

You stumbled into the main point, the problem with simple computers is always the memory. The CPU itself can always be made so simple that the memory is 99% or more of the work.

Wouldn't something like this do the job?

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