Re: frequency vs core saturation

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Steve Ward" <steve.ward@xxxxxxxxx>

Hi Scott,

You have heard right!  In magnetics, there is a trend towards higher
operating frequencies as they yield much higher power density than big
old iron cored transformers.  For example, a small ferrite core
(ferrite is kind of like a ceramic magnetic material, do a google
search if you want to know more) running at 50khz (yes, kilo-hertz)
can handle the same power as an iron core perhaps 5-10X its size.
This amounts to running more volts per turn on the same size core to
get higher voltages, while at the same current.

Normal 60hz transformers (if they use decent steel cores) should work
up to a few hundred hertz, where the input voltage could be increased
by the factor of which the frequency was increased, allowing for much
higher output voltages, but like you said, the insulation must be able
to handle this.  The main problem is finding some other power source
than 60hz mains.  If you are into power electronics like i am, then
you might just build yourself a 300hz power supply, but then you may
as well work with ferrites at 20-100khz and get an even smaller
transformer at the same power.

Check out my ferrite based HV power supply that runs the transformer
primary at 40V per turn (at 50khz of course)!

http://www.stevehv.4hv.org/ccps1.htm


Steve

On 4/6/07, Tesla list <tesla@xxxxxxxxxx> 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.
> Scott Bogard.
>
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