<mrdarrett@[EMAIL PROTECTED]
> wrote in message
news:bb341062-6a8f-4d0e-b4f9-7ee805e78362@[EMAIL PROTECTED]
> I've got a toroidal core, and I'm planning on winding it with pulsed
> 12VDC on the primary, and want to get out 50V on the secondary, center
> tapped so I can get +/- 25V.
>
> The 12VDC will be provided from a 555 switching a power MOSFET at 10
> kHz, 50% duty cycle.
>
> I'm hoping to get a maximum of 100W out of the secondary, so the
> secondary will be carrying 2 amps, and the primary will be carrying
> about 8 amps. I'll be using 22 gauge wire. (A little thin, I know,
> but it'll do at least for small scale tests at around 50W.)
>
> 12V / sqrt(2) = 8.5 V RMS. (Does this apply for pulsed square waves?)
>
> 50V / 8.5 = 5.9, so if the primary is of length X, the center-tapped
> secondary should be of length 5.9X, right?
>
> How many turns of primary are necessary for the transformer to work?
> In theory, only one turn of wire would be necessary (and then I'd need
> 6 turns on the CT secondary), but I know this is hogwash. How do I
> know how many turns I will need on the primary?
>
> Thanks,
>
> Michael
What's with the RMS? Your primary drive is 12 Volts peak to peak. Your
secondary is 100 Volts peak to peak. The turns ratio is 12:100. It's not a
matter of length but rather number of turns.
Be sure to drive the transformer through a capacitor to keep ALL DC out of
it.
The number of turns depends on the area of the core and the maximum flux
density, Bm for the particular core. The core material must not have too
much loss at 10kHz.
You need to know something about the core, it's size and material.
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