Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!ucbvax!hplabs!hp-pcd!hplsla!tomb
From: tomb@hplsla.HP.COM (Tom Bruhns)
Newsgroups: sci.electronics
Subject: Re: Transformer Troubles
Message-ID: <5170046@hplsla.HP.COM>
Date: 20 Jul 89 17:20:09 GMT
References: <536@winnie.fit.edu>
Organization: HP Lake Stevens, WA
Lines: 27

acs60222@zach.fit.edu ( ENRIQUEZ) writes:
>
> ...
> 
> slight EE experiance, I began to think about putting another, smaller
> transformer is parallel with the other to increse the driving current.
> However, I doubt this simple idea can work and would enjoy hearing why
> it would not.
> 
Actually it should work just fine, _IF_ the turns ratio is identically
the same.  There is an effective series resistance associated with each
transformer's output that will cause them to share the load as the
inverse of the ratio of the resistances.  It would be best to use two
identical transformers; then they would share the load equally.   You
can also put a small autotransformer in to account for slight voltage
differences between two equal-VA but slightly different-voltage
transformers.  The autotransformer would be small compared with the
other two if the voltage difference is small.  But an even better way:
you may also be able to locate a large transformer that will handle the
whole thing, at a very reasonable price, if you spend some time looking.
I've picked up 500 VA (nominally 500 watt) transformers for as little
as about $2.00, in the voltage range you are interested in.

> I appreciate any and all discussion about my problem...
> 
> Thanks   me
> ----------