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Re: Magnetizing current in SSTCs, my previous posting



Original poster: "K. C. Herrick by way of Terry Fritz <teslalist-at-qwest-dot-net>" <kchdlh-at-juno-dot-com>

OK, folks...here's the whole enchalada: a secondary-feedback
simulation-circuit for a 2-turn-primary solid-state coil.
http://hot-streamer-dot-com/temp/2-t-feedback.pdf.

1.  V1 provides a bit of noise that couples thru C7 & R8 into E1.  E1's
output is clamped by D3 & D4 and that voltage is fed to E2-E5.  In a real
linear circuit with sufficient gain, the noise is provided by
circuit-noise & C7's lower end is grounded.

2.  The E2-E5 noise-outputs drive TX1 and start the secondary oscillating
at its Fr.

3.  The secondary's Fr current thru C7 produces a voltage across C7 90
degrees out.  This voltage is 180 degrees out from what's wanted to drive
TX1 (or 0 degrees out depending on TX1's winding-sense).

4.  The C7 voltage is coupled thru R8, clamped by D1 & D2, amplified &
inverted by E1, clamped again by D3 & D4 and applied to E2-E5.  In a real
circuit, D3 & D4 likely would not be used since E2-E5 would have only so
much supply voltage to work from and the amplifying chain would be
otherwise configured to supply the proper voltage levels to the E2-E5
inputs.

5.  R1 and R4-R7 represent component- and circuit-resistances, of course,
and must be absolutely minimized for best operation.  Lots of amps there.

6.  So voila!...TX1 becomes excited at its exact Fr.  It simulates "just
as advertised".  And this feedback scheme works for sure since I've built
and run it.

Get to work, people!

Ken Herrick