Question about switching transformer series/parallel

Thread Starter


Joined Jun 5, 2018

I recently just spent quite some money on equipment which I've always wanted: a big 600VA transformer and some extra parts to rectify and use it.

The transformer:
24-0-24V; 2x12.5A.

My idea is to make a power supply in which I can flip a switch so the wiring can change: Series; off; parallel. That way, I could get 48V or 24V with double the current.

I've tried asking around a few friends of mine but no one really knew how to do it. I would appreciate it if you guys would help me out with this as I really don't want to blow up the transformer or the $18 capacitor for it.


Joined Nov 13, 2015
Since the two secondary windings have a fixed connection for the center tap, you can not connect them in parallel. You would need to have two independent 24 volt secondary windings.


Joined May 3, 2013
Use a Bridge Rectifier. You will have 24 Volt Bi Polar supply; 48 Volts overall.

Such a high capacity transformer is very likely to have 2 independent windings connected together as a centre tap. In which case, you can separate the windings and get what you want to do.


Joined May 3, 2013
You can use a DualPoleDualThrow to choose between Parallel and Series setup.
If you use a DualPoleTripleThrow, you can have a Open in between.

Just make sure that the contacts are rated to handle the current. Also ensure that, when parallelling,
* the voltages in the 2 windings are exactly the same, else you will have circulating current between the windings
* Polarity of the windings so you dont create a dead short.
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