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Help with a homemade test set

I have an old home made "test system" that was made by my father, a test set designer for Western Electric PBX, in about 1969. It was given to me for Christmas and was called a "Computer". I now have a 5 year old son and he wants me to get this working again.

The first problem I am having is that I was a real boy and took it apart and lost some of the wires, and broke off some of the connections

when I was young.

The second problem is that my father pasted away 3 years ago and we did

not fix it before he got sick.

The third is that I have not worked on circuits for far to many years.

What this did was when the dial was turned it would light one of 10 lights across the top.

The test system has a 45 volt battery a western electric dial and a circuit board. The circuit board has 10 identical components. It looks like a resistor, to a transistor from there to a capacitor then to a diode and then to another capacitor. The first lights ground is hooked to all the other lights and to the dial on the Y terminal then the other side of the light is connected to the circuit. The BK terminal looks to go to the start of the circuit board. The BB terminal looks like there was a wire there, but none are connected. I can not find where the power should be connected, or where the ground should be connected.

Please help me, my Son is driving me nuts and I can not believe I broke

this and never asked for help to fix it.

Reply to
rsnella
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Can you post a schematic of what you have to alt.binaries
schematics.electronic?
Reply to
John Fields

I will try to do so latter today.

Reply to
rsnella

That's a new one to me. Probably carried by a minority of news servers. Putting a schematic on a website and posting a link here works.

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Dave Farrance
Reply to
Dave Farrance 

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The only people that can\'t seem to access it are Google groupers.

Can you?
Reply to
John Fields

OK I have tried to make the schematic the best I could. I have posted it at

formatting link
it is under Test Set Project.

I also included 3 photos of the project.

Thank you for any help.

Russ

Reply to
rsnella

Ahem. Check your HTML. You've misspelled the links.

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Dave Farrance
Reply to
Dave Farrance

That should be "van" not "vam" in your URLs.

It appears that your problems are not too serious. The circuit is a ten-stage "flip-flop" where the trigger signal goes into the network of capacitors annd diodes that meet at the resistor near the bottom of the page. Connect one terminal of the dial to that resistor. The other terminal of the dial goes to the (-) side of the power supply, and so does the broken return connection from all the lamps.

-- Joe Legris

Reply to
jalegris

The urls have been fixed. Sorry to late of a night.

Reply to
rsnella

This is only an educated guess, but I believe it is a prototype of a test set for testing pulsing operation of an external relay.

Don

Reply to
Don Bowey

I vaguely recall having seen something similar in some magazine in the

70s. Basically a ring counter based on programmable unijunction transistors (PUTs). I'll see if I still have anything about it in the attic, don't hold your breath. In the meanwhile, try to find a type number, google on that, PUTs and ring counters.

- YD.

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Reply to
YD

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