Transformer question (only slightly OT)

[Tony Duell]

> 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.  Obviously,
> 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