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Re: Transformer

Original poster: Finn Hammer <f-h@xxxx>


You appear to be where i was only a year ago. At that time, I had great assistance from this small publication:
which is the instructions for the Plasmasonic board made by Daniel McCauley.

But to answer your question, the Fet`s/IGBT`s should conduct crosswise,
1: left up, right down conducting        (current trough coil one direction)
2. none conducting  (called dead time)
3: left down, right up conducting         (current trough coil other direction)

If you have:
left up, left down conducting, there is a short across the rails. this situation is called shoot trough. You`l recognize it imediately, because that`s when the devices explode, and fly all over the place. Happened 13 times to me, before I got the picture. Luckily, fet`s were cheap.

The primary coil is connected to the mid-points of the silicon´s, and controlling the devices like this, shifts the polarity to the primary coil. The coil is connected to the + or - rail by a conducting device. By controlling the devices like shown, the polarity across the primary coil is alternated at the driving frequency, which should be the secondary res. freq.

This is how you create the alternating magnetic field, which lures the secondary into pumping electrones on and off the topload.
This topload, which is by good fortune, both mechanically so large that it withstands high potentials without breakout, but also electrically so small, so that even a moderate current will cram electrones onto it with such relative abundance, that extremely high potentials are reached.
I said lure, because there is resonance in the secondary at the frequency used in the primary. Power is applied, but hardly any force is involved. This whole resonance thing, not at all unlike intercourse in a waterbed.

Hope this helps.

Cheers, Finn Hammer

Tesla list wrote:

Original poster: "Alexander Turkin" <alex_3@xxxxxxx>


My question is about gate drive transformers in the H-bridge SSTC. For example, in Richie Burnett's circuit (or any else)
For example, if the left upper MOSFET is turned on, what another MOSFET should be turned on (the right upper or the right lower)? I've seen both variants in the internet. But what is correct?