I've got a power supply PCB that takes 230VAC and I need it to run on 110VAC.
I'm comfortable working with DC circuits, but don't have much experience working with alternating current.
I'm assuming the transformer would need to be changed out for one with a 110v primary, although one of the 3 wires on the primary side isn't connected to anything, and from looking at the markings on the board it would appear that these have the option for being configured for different input voltages at the factory.
Any suggestions would be greatly appreciated

 

There shows a multi tap setting on the board for six voltage setting for the primary by the look of it.
Max.

 

There shows a multi tap setting on the board for six voltage setting for the primary by the look of it.
Max.

Ok, great! How would I go about configuring that? There are no jumpers or dip switches anywhere.

 

Can you post a photograph of the copper side of the board?

 

Although a second look, it does not appear that all the primary taps are brought out, it only appears to show two?.
Max.

 

Can you post a photograph of the copper side of the board?

there are 3 inputs on the primary side, and 7 outputs on the secondary, the bottom 2 are much heavier gauge wire than the top 5

 

I'm looking at imag0060 and although the pins go through the PCCT board, there is no conductors connected to them as in the other two?
It needs a continuity test to verify.
Max.

 

I'm looking at imag0060 and although the pins go through the PCCT board, there is no conductors connected to them as in the other two?
It needs a continuity test to verify.
Max.

The 3 wires from the primary go through the board, the center one and left one seen in 0060 go to copper traces, and the right one just goes to an isolated pad. They can be seen in img0061 on the middle left of the board. I'll try and label what I can identify and post another picture of the copper clad side.

 

 

It would appear the transformer does not have the terminals wired for multi-tap use as shown on the PCCT board, there only appears a pair, if so it may be just a single voltage transformer.
Max.

 

It would appear the transformer does not have the terminals wired for multi-tap use as shown on the PCCT board, there only appears a pair, if so it may be just a single voltage transformer.
Max.

Ok, so I would be best off trying to replace the transformer with a 110v one?

 

It does not appear to be all that a high wattage unit, so you could obtain a 240v/120v transformer and run it 'backwards' for that size of transformer it should not hurt.
You would need to place it in a suitable enclosure of some kind.
It might state the wattage of the device somewhere.
Max.

 

Ok, so I would be best off trying to replace the transformer with a 110v one?

That's probably going to be tricky unless the manufacturer lists the part you need as a service spare.

Many component houses stock mains transformers with 2 identical 110V primaries - you wire them in parallel for 110V and series for 220V. You simply use it as an auto-transformer and ignore any secondaries. I operated an American all band radio like this for the long time it took to find a 220V transformer with the right secondaries and physically fit.

It needs at least the same VA rating as the one in the equipment, and a suitable enclosure with appropriate cable strain relief.

 

I go with post # 10

 

It does not appear to be all that a high wattage unit, so you could obtain a 240v/120v transformer and run it 'backwards' for that size of transformer it should not hurt.
You would need to place it in a suitable enclosure of some kind.
It might state the wattage of the device somewhere.
Max.

Some people use a pair of identical transformers back to back for isolation, but losses add up and you get less than the original voltage.

If that isn't a problem it can be as simple as using 2 same rated transformers with primary voltages as required.

Its one of several ways of going about it. The split primary transformer used as an auto transformer does the trick with only one physical transformer - and AFAIK: less losses.