power transformers 220 volts to 110 volts

[garydmd]

power transformers 220 volts to 110 volts

Hi there,

I was just wondering, there are a lot of cheap voltage transformers that convert 220vac to 110vac so you can go from european power to us power. I am not sure what is exactly in these, but if it is just a simple transformer, could you hook up the primaries to 110v ac and secondary output would be 55v ac?

Thanks,
Gary

 

[AndrewT]

Hi,
they are just a 2:1 turns ratio mains transformer.

If you run a 220Vac transformer on 110Vac you will reduce the VA rating to about half the 220Vac value. i.e. you will overheat it if you try to take the original power out of it.

If you convert a dual primary 110+110 transformer to run on either supply you can obtain the full VA rating from both supply voltages.

 

[pinkmouse]

The other thing to bear in mind is that a lot of these are autotransformers, thus have no isolation and are dangerous to use on their own.

 

[Peter Daniel]

I've built two such units for 6moons publisher and he is very happy with them: http://www.6moons.com/audioreviews/240_117/240_117.html

Additionally, you can implement balanced power configuration, which brings further improvement over regular step down setup.