Power Supply Question?

[khstudio]

I have an extra power supply board, very similar to the JLM ACDC, that I pulled from another 8 channel pre-amp...
It has +/- adjustable rails & 48v.

The problem I'm having is it was originally designed to have a dual power tranny input - one Center Tap with 2 separate (pairs) from the tranny & 5 pin input on the card.

- One for 48 & one for the +/- rails, each one goes to it's own bridge rectifier.

Could I just split a single pair power tranny output to each rectifier or do I need to add other components?

I have it working now BUT only on the +/- rails... no 48v yet.
Just want to be sure so I don't screw it up, it's a nice one.


Thanks,
Kevin

 

[khstudio]

My first post might be confussing... I'll simplify my question:

Can you run a single Power Transformer to 2 bridge rectifiers :?:


Kevin

 

[bcarso]

The general answer is no---bridge rectifiers don't provide any isolation. In some specific case you might be able to without blowing things up---but then the question would be, what is the point? Unless it's an issue of a bridge being underrated for the amount of current pulled, there's nothing gained.

We* would have to see the original schematic to know for sure what is going on and make recommendations.




*that is, forum stalwarts, not a "royal we."

 

[khstudio]

OK, I'll try to trace the circuit a little in the front end.

Thanks,
Kevin

 

[Greg]

Often times a voltage doubler or tripler is used... it's made with a couple caps and 4 diodes. For example, look at the JLM PSU schematic. There are 2 groups of 4 diodes. One is a bridge rectifier and one is a voltage doubler. Notice that the diodes aren't oriented the same way.

I take it you don't have the original power tranny handy?

Perhaps you could try to dig up or trace the PCB to get a schematic.

 

[datape]

Hey Greg, I think that there were two bridge rectifiers in the JLM circuit. The 48v is obtianed using a pump charge circuit.

[quote author="Greg"]Often times a voltage doubler or tripler is used... it's made with a couple caps and 4 diodes. For example, look at the JLM PSU schematic. There are 2 groups of 4 diodes. One is a bridge rectifier and one is a voltage doubler. Notice that the diodes aren't oriented the same way.

I take it you don't have the original power tranny handy?

Perhaps you could try to dig up or trace the PCB to get a schematic.[/quote]