Hello everybody, I'm new to electronics as a hobby so bear with my lack knowledge. I have access to all sorts of electronics junk in my job and I learned long before I got into this to not throw anything away. I have a couple of transformers labelled 347v 60hz 120v 30va. It's my understanding this steps down 347v to 120v at a max 1/4 amps, correct? My question is, can I use this to step down 120v and what would be the effects? Meaning I would get about 40v but what amperage? Would it still be 1/4 amps or would it still be 30va so work out to 3/4 amps or would it be some other value all together?

 

using 30 VA is the safe bet, but you likely could draw 10-20% more without a problem. monitor temp rise to determine limits. intermittent use allows higher current draws with cool down in between active periods.

 

If you ever needed 347vac you could run it backwards off of 120v!
Max.

 

I sould not increase the output current, it's set by the wire size, and keeping the va the same would double the currrent.

 

alfacliff has it. The diameter of the secondary wire is designed to carry 1/4 amp. Try to get 30 VA out of that at 1/4 the voltage and the heat goes up to burning level after just a few minutes.

 

Thanks guys. I figured that was the case, just wanted confirmation.

I got some magnetic ballasts too, this is the biggest. I have no idea what I may use them for.

 

They are stamped auto transformers and are Holophane!!
Max.