Re: It works! Solid state driver (fwd)

From: 	bmack[SMTP:bmack-at-frontiernet-dot-net]
Sent: 	Thursday, December 04, 1997 10:12 PM
To: 	Tesla List
Subject: 	Re: It works! Solid state driver (fwd)

> Date: Wed, 3 Dec 1997 20:48:24 -0700
> From: Don Huff <w6jl-at-e-z-dot-net>
> To: Tesla List <tesla-at-pupman-dot-com>
> Subject: Re: It works! Solid state driver
> Hi Max,
>   CONGRATS on the encouraging work with your SS driver.  Are you using a
> half-bridge?  Sounds like it (2 FETS per leg, 4 total, must be 2 legs,
> half bridge, yes?).    1 KV AC is what you will be driving your primary
> with, right?   I would think you would be running the half-bridge at
> whatever frequency your primary system will be resonant at, is that
> No rectifier, just AC square wave drive.   No spark gap, just ringing the
> primary LC with an AC power source at the resonant frequency.  Am I
> correctly describing what you are doing?  I am interested in this
> if it can be an alternative to spark gaps.
>   Good luck, and give more details if you can.  I am pretty familiar with
> switching power supply topologies and design.
>      Don, W6JL
In fact, you don't even need a primary cap!
I have made two coils with this configuation with reasonable success.
The first was a *very* low power flyback-type driver. The flback ring was
tuned to the TC resonant frequency, while the total period was equal to
the TC freq. This allowed a 50% duty cycle( or therabouts).  Getting it
just right was a tricky edeavour, but it did work.

Push-pull forward mode is much easier and able to deliver whatever power
you need(or want).  With careful design it is also very efficient.
My second one is 150 watts input  running at 1 mhz.  I LIKE IT.
Others on the list may not appreciate as I do since its not a "sparker"
due to the high frequency, but it develops one hell of an E field from
24 volts!

I'M sure it will make a fine "sparker" at the 200khz that Max is using.
We'll soon find out.

DUMP THE RSG! ------IT's 1997

Jim McVey