I salvaged this board from an old water purifier. Now after looking at the board i can see a prismatic power supply is built in it. But i don't understand how does it work. I have provided a simplified sketch. Can you tell me(yah i know I'm sounding dumb) what can be the output voltage? I was going to make an amplifier where i would need 12-0-12 v power supply. Can i use this?

 

First, “Prismatic” is just the name of the transformer manufacturer, it’s not relevant to the circuit or its operation.

Second, the circuit to the left of the line is a bog standard AC to DC supply using a bridge rectifier. Filtering, though, are conspicuously absent to the output will be very ugly with a lot of deviation from a straight line DC signal.

From the information you provided there is no way to know what voltage it supplies, haven’t you measured it?

What do you mean buy 12-0-12V? do you mean +12V/-12V?

You might find some of the parts salvageable, but as it stands it doesn’t seem it would be particularly useful to you in your amplifier project.

 

First, “Prismatic” is just the name of the transformer manufacturer, it’s not relevant to the circuit or its operation.

Second, the circuit to the left of the line is a bog standard AC to DC supply using a bridge rectifier. Filtering, though, are conspicuously absent to the output will be very ugly with a lot of deviation from a straight line DC signal.

From the information you provided there is no way to know what voltage it supplies, haven’t you measured it?

What do you mean buy 12-0-12V? do you mean +12V/-12V?

You might find some of the parts salvageable, but as it stands it doesn’t seem it would be particularly useful to you in your amplifier project.

First, “Prismatic” is just the name of the transformer manufacturer, it’s not relevant to the circuit or its operation.

Second, the circuit to the left of the line is a bog standard AC to DC supply using a bridge rectifier. Filtering, though, are conspicuously absent to the output will be very ugly with a lot of deviation from a straight line DC signal.

From the information you provided there is no way to know what voltage it supplies, haven’t you measured it?

What do you mean buy 12-0-12V? do you mean +12V/-12V?

You might find some of the parts salvageable, but as it stands it doesn’t seem it would be particularly useful to you in your amplifier project.

I have an old school 12v step down transformer which got 2 output wire coming out of it, also had one with 3 wires coming out of it written 12-0-12 but it's burnt and damaged. For the class d amp i need a 12v 3 amp power supply dc. Can you provide any schematic or pcb layout for it. With the help capacitor and diode bridge rectifier i built one power supply but that's too heavy.

 

The transformer type you are describing is center tap. The voltage from either outside wire to the center one will be 12V, the two outside wires will have 24V on them.

There is no way I can provide any information about what to build because you’ve provided no specifications beyond “12V”. I don’t even know what you mean by “too heavy”.

If you want help you will have to be specific. e.g.:

“I need a power supply that provides 12VDC@<xA>
I have a transformer from <manufacturer> part number <part number> I would like to use.
I have a budget of <xxx> and a deadline of <n days>”

There is no guarantee that I or anyone else here will be able to help even then, but you are leaving so many things unsaid we surely can’t now.

Why don’t you just buy a cheap supply? They are everywhere.