odd question about exidy board switching

ThumB

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I'd like to put my pepperII board in my mousetrap and have a way to flip a switch to swap from one to the other. I cant do this by converting them to jamma and using a switcher (they run -12v). They do run the exact same pinout (except for the buttons in mousetrap, pepperII has no buttons)

Is there some sort of terminal bay i could use that switches between one bay to the other?
I realize this is insane...but so am i.

~s
 
I'd like to put my pepperII board in my mousetrap and have a way to flip a switch to swap from one to the other. I cant do this by converting them to jamma and using a switcher (they run -12v). They do run the exact same pinout (except for the buttons in mousetrap, pepperII has no buttons)

Is there some sort of terminal bay i could use that switches between one bay to the other?
I realize this is insane...but so am i.

~s

The first thing I would do is add up the power wires that are used and figure a way to switch just them. Maybe with a relay or two you should be able to switch the power from one to the other. This is do able but can lead to problems and head aches. You will need two connectors, one for each pcb. I have tried something like this with limited success but had better luck with less wires and just switching the ground wires (running ground from power supply to relay and to the board to be powered up) This worked but I don't like or recommend it. Project is on shelf.
 
i did think of this. my other option would be to find a Wei Ya type power supply that has -12v. Does anyone know if these exist?
then i could switch from the power source and just put resistors on all the wires to stop feedback.
 
There are power supplies that run -12vdc, in fact they are fairly common.

If I was doing this I would grap a power supply that supplies the voltages I need and use a Jamma adaptor with the -12vdc used in place of one of the other power lines, most likely one of the -5vdc (both if -5v isn't used).


There was also a relay based switcher that was produced in the early 1980's. It is a bit more complicated to use and hard to find but it would be a "vintage" method of doing what you want.
 
wow that thing is wack! never seen that before.
Yes exidy uses both -5 and -12.
I realize there are -12v power supplies. just dont know where to find a Wei Ya type power supply
 
You'd need to switch speaker lines as well. You run the output of one amp into the output of another (even if its powered off) and you'll destroy one or both of them.
 
You'd need to switch speaker lines as well. You run the output of one amp into the output of another (even if its powered off) and you'll destroy one or both of them.

This is one of them head aches I was talking about :).

Speaker lines also don't like extra wires hooked up to them either and will pickup noise. Do a search here on the forums about speaker humm.

I think in my project I use a blocking diode on one try and a knife switch on the other try. I haven't tried a relay or a cable switch box a/b yet but that was next.
 
wow that thing is wack! never seen that before.
Yes exidy uses both -5 and -12.
I realize there are -12v power supplies. just dont know where to find a Wei Ya type power supply


I figured it would use both, I was saying dedicate one of the -5v lines to carry -12v. The -5v lines usually have a low current draw and can usually handle being supplied across only one connection point.

If I were to do this I would put plenty of warnings in the cab about the non-standard Jamma. I tend to use my cabs for testing at times and I would hate to fry a board because I forgot something like this.

What do you mean by a 'Wei Ya' type? Are you concerned about the power connection points? Maybe the footprint of the power supply?
 
This is one of them head aches I was talking about :).

Speaker lines also don't like extra wires hooked up to them either and will pickup noise. Do a search here on the forums about speaker humm.

I think in my project I use a blocking diode on one try and a knife switch on the other try. I haven't tried a relay or a cable switch box a/b yet but that was next.

Speaker wires won't pick up hum. Its a high level low impedance circuit.

Input wiring to the amp circuit is where you need to worry about noise pickup.
 
"What do you mean by a 'Wei Ya' type? Are you concerned about the power connection points? Maybe the footprint of the power supply?"

i wasnt worried about the footprint. I was just wanting to bypass the huge massive 4 board, 3 transformer monster of a power supply that is in the cabinet!
 
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