mystery component

thatoneguy

Joined Feb 19, 2009
6,359
What is this circuit out of? Vintage? At a guess, tantalum capacitors.

Especially if they are across the power rails on the other side of the board.
 

MrChips

Joined Oct 2, 2009
30,824
I have seen tunnel diodes that look like those. But why would they use tunnel diodes in that circuit? It would help if we knew the function of that unit.
 

THE_RB

Joined Feb 11, 2008
5,438
They are rectifier diodes as the transformer rectifier.

ie split secondary winding -> dual rectifier diodes.

And one looks a bit cooked. :)
 

GopherT

Joined Nov 23, 2012
8,009
I'm going with rectifier diode too. The two white wires say 24AC, so I am guessing that is the input from the transformer.

Who ever correctly predicts what this device does befor the OP tells us, wins! You only get 24 hours of bragging rights as your award since I don't have your address (and don't want your address).
 

#12

Joined Nov 30, 2010
18,224
In 1971, I had what we called, "green dot" rectifiers in my truck stock. They were obviously manufactured with axial leads. Those "black dot" devices look like radial leads, severely bent. I also think they could be rectifiers but question why a manufacturer would bend a radial lead device into submission when axial lead rectifiers were available 7 years before these parts were installed.
 

#12

Joined Nov 30, 2010
18,224
The blue things with holes are an early form of plastic transistor package that resembles a small TO-220.
 

THE_RB

Joined Feb 11, 2008
5,438
...Who ever correctly predicts what this device does befor the OP tells us, wins! You only get 24 hours of bragging rights as your award since I don't have your address (and don't want your address).
Hmm, it's a lowish power device running from 24vAC and a 2 diode rectifier. It has a 4017 ring counter IC and an unknown IC with at least 3 transistors in a space-critical layout, not heat critical so they don't drive big loads.

The 4017 runs up to 10 things in sequence, they were used mainly in things like light chasers and lighting effects. Also they were used in things like electronic organs for arpeggio (note sequencing) effects.

Of the two I would pick some type of lighting flashing controller.
 

#12

Joined Nov 30, 2010
18,224
It's beginning to look like a, "drive by" thread.
(Bonsaimaster1 dropped off a question and kept on going.)
We might never find out what it is.
 
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thatoneguy

Joined Feb 19, 2009
6,359
I think The RB is onto the purpose, a sequencer of sorts.

I remember seeing those odd green transistors in another circuit, I forget the name, TO-220AB or something, but that pale green color sears a scar in your mind.
 

Thread Starter

bonsaimaster1

Joined Feb 8, 2013
10
Thanks everyone for replying I just tried a axial leaded varieties for the board and it didn't work and I tried a few diodes none are working I think I need different voltages in both varistors an diodes, if anyone has other thought to what they are please reply and FYI the board plugs into a Japanese pachinko machine which controls the tulips to open and lights with sound.
 

thatoneguy

Joined Feb 19, 2009
6,359
What does the circuit do?

Can you post a photo of the back of the board as well as a larger image of the front?

What do the items measure out of circuit as? Short/open/diode test, cap test, etc?
 
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