Re: frequency vs core saturation

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Antonio Carlos M. de Queiroz" <acmdq@xxxxxxxxxx>

Tesla list wrote:
> Original poster: "Scott Bogard" <teslas-intern@xxxxxxxxxxx>
>
> Hey all,
>     Here is a question for all you mathy theoretical technical guys.
> I heard In physics class tonight, that if you use a higher frequency 
> you can use a smaller core for a transformer.  In my mind this 
> means, if you use a higher frequency, you can pump more voltage 
> through your primary, and consequently get more out of your 
> secondary.  This means (provided you have enough insulation) you 
> could use a much higher voltage in your TC primary, with the same 
> transformer, by changing the input voltage and frequency, without 
> saturating the transformer core.
> So my question is, is this beneficial in any way?  Is this even 
> true, or is my logic flawed?  I (as of right now) have no means with 
> which to experiment with frequency and input voltage, but mabey 
> somebody else out there does.  Thanks a heap.
In principle, this is true. A transformer will not saturate if you 
double the input voltage and double the input frequency.
But there are other considerations (considering doubling):
In a high-voltage transformer, the insulation may not support the 
doubled output voltage. Serious limitation.
The core losses will increase. Maybe a problem.
The leakage inductances will present twice the original impedance, 
and so the short-circuit current remains the same. Not so serious.
How to change the input voltage and frequency? You will have to make 
a robust switched power supply for this. Not trivial.

Antonio Carlos M. de Queiroz