82Views9Replies

Author Options:

Connect two transformers in parallel? Answered

Hi! I have a question in case someone can help me.

I need an AC/AC converter from 120V to 12V for a halogen lamp. The required output is 210W, but I can't find a big enough transformer for this. Is it possible to connect two, 105W output transformers in parallel in order to achieve the desired 210W?

9 Replies

user
icengBest Answer (author)2018-01-18

Just saying, I have successfully mixed identical transformers and a 24V 4A in parallel with a 24V 2A...

The rule is go ahead and parallel two transformers JUST make sure they are in phase otherwise it will be a double short circuit..

Select as Best AnswerUndo Best Answer

user
seandogue (author)2018-01-18

As I recall it's not recommended to apply parallel transformers for a single load (you could wire up two identical transformers to power different loads), but it's been a while so I'm not positive of my claim.

Select as Best AnswerUndo Best Answer

user
seandogue (author)seandogue2018-01-18

update, ... google/bing

"transformers in parallel"

https://www.bing.com/search?q=transformers+in+para...

Apparently you can as long as you follow the rules set forth in the top most return in that link

Select as Best AnswerUndo Best Answer

user
steveastrouk (author)seandogue2018-01-18

...or "Without advanced knowledge and identical transformers, don't"

Select as Best AnswerUndo Best Answer

user
JuanC368 (author)2018-01-19

Thanks for all the help. It seems like it's possible, it's just a matter of making sure they're in phase as iceng said.

Select as Best AnswerUndo Best Answer

user
steveastrouk (author)JuanC3682018-01-19

No, its a matter of making sure they are IDENTICAL, or adding resistors to break the current loops.

Select as Best AnswerUndo Best Answer

user
iceng (author)steveastrouk2018-01-19

Yes, If the magnetizing current is different as in the iron laminations being different, I do believe there would be a phase shift in the secondaries and that recirculating 12v lamp with the clip removed would really light up..

I'm still trying to find the video of that experiment showing no recirculating current...

Select as Best AnswerUndo Best Answer

user
Jack A Lopez (author)2018-01-18

Does it have to be 12 volts AC?

I mean if the load is just the filament in a big halogen lamp, it might be just as happy with 12 volts DC, supplied by something that is capable of giving 17.5 amperes of current, or whatever it is.

I mean, that's the number I get when I divide 210 watts, by 12 volts.

A car battery might work, preferably one that is attached to a car, because 17.5 A would drain the battery in a matter of hours, without the car's engine to recharge it.

Select as Best AnswerUndo Best Answer