[FallenAngel]

Hey guys,
 
I'm having a total brain fart here (perhaps because I'm not an EE and never formally learned this).
 
I'm looking at a power transformer, it has a single 230V 50Hz primary and 74VCT secondary, this exact model http://shop.plitron.com/specs/480103.pdf
 
My question is simple : if I simply use it with 115V primary (North American 60Hz), I should expect 37VCT secondary output at same amperage, right?  Will the different frequency have any effect?
 
Thanks in advance.

 

[holland]

I don't know for sure, about 50Hz vs 60Hz, but I don't think it should be a problem.  Half should be roughly close.  Don't exceed the current rating.  There's quite a size difference, IMO, between 370VA and 185VA.  Why not just get the right size?  It would take less space, weigh less, and probably be cheaper.

 

[FallenAngel]

Oh, I was actually expecting that it would still be 370VA and as for cheaper... that one is $50 and under half the price of a similar rated Plitron.

 

[holland]

ah, i see.  no you can't maintain VA.  It's not just about power, though power is directly related to the heat spec.  The size of the wires, the size of the core, and the number of turns, will dictate the amount of current you can put through.  This deals with core saturation and the wire spec.  Assuming your wire can handle the increased amperage,  (10A instead of 5A...which is very large), you need to presume that the core is *close* to saturation at 5A (for cost reasons from the manufacturer).  Doubling the current through the core will blow past the saturation limit by a huge margin.
 
Saturation_(magnetic)
 
I'm hardly an expert on this though.  It may be wise to call Plitron about it, though I'd expect a similar answer, but more technically correct, from them.

 

[FallenAngel]

Ah, of course, total brain slip about VA actually being related to V x A 

  It's been a VERY long week.

 

[looser101]

Shipping is killer on large transformers.  Why not get what you want/need and go pick it up.  Both Plitron and SumR are local (GTA).  Plitron would probably be the easiest to get to from where you are.