Re: variacs

At 09:30 AM 1/19/96 +0700, tesla-at-grendel.objinc-dot-com wrote:
>>From chip Fri Jan 19 09:16 MST 1996
>Date: Fri, 19 Jan 1996 09:16:32 +0700
>From: chip (Chip Atkinson)
>To: tesla
>Subject: variacs
>I saw a gang of 3 phase variacs for a reasonable price ($15) at the local
>electronics surplus/supply place.  However, the variacs are 400Hz instead
>of 60Hz.  Does anyone know if they will work ok for 60Hz?  I thought the
>main considerations with different frequencies for transformers are eddy
>current losses.  If that is true, wouldn't a transformer for a higher
>frequency work fine for a lower one?

Hi Chip,

For that price, I'de be inclined to buy it for the "might come in handy for
something one day" 'excuse' to myself! 
Thats not much of a frequency difference really. Bareley in the AF spectrum!
I would just buy it and test the current and voltage, and try a 'dummy load'
like light bulbs? or something? See how much wattage can be comfortably
handle without the variacs getting too warm.
I think higher frequencies are more efficient 'power for core weight' wise. 
I might be right. :) Take a HF ferrite for example. These things will saturate
till theyre nearly aflame. And they can be pretty small compared to 'mains'
frequency trannys in terms of power handling.
But I dont think there would be a large difference. Of course, others may