2 Sep
2006
2 Sep
'06
3:01 a.m.
From: "Tony Duell" <ard at p850ug1.demon.co.uk>
Obviously,
Most of the old transformer "kits" (wind your own secondary), supplied
by
the likes of RS, required you to parallel the 110V primaries in order to
achieve the full VA rating at 110V.
Paralleling the secondaries is fine, you will only saturate the core if you
exceed the VA rating of the transformer (assuming a correctly designed
transformer). However, it is always better to use full wave rectification
(centre tapped or Bridge), to avoid any DC component in the secondary, as
this can lead to saturation at lower VA loads than would be normally
expected (unless the transformer is designed for half wave rectification).
Jim.
> At any rate, I want to use this transformer in a
DC power supply. I
have
> three sets of windings: two sets are 120/240v
"universal"
series/parallel
> type and the third is 24-0-24v center-tapped.
>
> I want to run this from 120vac.
>
> Is there any benefit to paralleling the two sets of 120/240v main
windings
> (i.e. 4 120v windings in parallel)? Will it
increase the power rating
of
the unit or is
that mostly a function of the secondary winding?
In a lot of cases, the limiting factor is the primary winding (often when
a transformer burns out it's the primary the fails). So yes, I would
paralelle up both sets of windings. Is there a reason not to?
>
> Suppose instead of 24-0-24 on the secondary, I'd like 12-0-12. > one way to get this is to hook the primary (-ies)
up as 240v. Is there
any
benefit to be
gained in parallelling the two 240v primaries?
Again, is there a reason no to?
-tony