Circuit board voltage

[Angelic]

I have several interesting circuit boards I would like to experiment with. But I am not sure if they require ac or dc voltage. Or how much. Can anyone help me figure this out?

[Thaelin]

  Start by looking for voltage regulators ie: 15v 12v 9v 5v. Take a list of the chips and or IC's and look up their specs. Trace the power rails back to the input plugs. Big caps usually have the job of smoothing out the power inputs, see what voltage they are.
  When you know the input, start out with a variable supply at 5v  and look at the chips for activity on their pins.


Have a fun journey.
thay

[Magluvin]

I have several interesting circuit boards I would like to experiment with. But I am not sure if they require ac or dc voltage. Or how much. Can anyone help me figure this out?

Post some pics.  Some circuit boards have identifying labels or numbers that can be searched to find out what they are for.
Mags

[Angelic]

It will take a few days to get pics. I love high voltage circuits that can be purposed.