RE: SSTC - experiments

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: humanb-at-chaoticuniverse-dot-com 

Thanks for the info Jan. I probibly am not going to
tackle a audio modulated SR-STTC anytime soon ;0 But
was curious. Dave Sharpe sent me a preliminary copy of
his design using the IR2153 chip, said he has yet to
test it. It does look quite interesting.

Regards,

David Trimmell

On Mon, 12 Jan 2004 11:46:16 -0700, "Tesla list" wrote:

 >
 > Original poster: Jan Wagner <jwagner-at-cc.hut.fi>
 >
 >
 > On Sun, 11 Jan 2004, Tesla list wrote:
 >  > Original poster: "David Trimmell"
 > <humanb-at-chaoticuniverse-dot-com>
 >  >
 >  > Steve, why wouldn't a "self-resonant" system work
 > for a audio modulated
 >  > SSTC?
 >
 > "Traditionally" audio modulation is done by
 > pulse-width-modulating the
 > drive signal, that is, making the pulse duty cycle
 > smaller than 50%,
 > proportionally to the audio input voltage.

 >Snip ..........................>

 > (Btw, has anyone actually tried this IR2153 design
idea
 > yet? Dave?
 > Someone else? Would be interesting..)
 >
 > I've never tried the IR2153 but it appears to use a
 > simple RC
 > oscillator. If you use an R-C combo you could add the
 > audio as a "DC"
 > offset from ground e.g. don't connect the timing cap
to
 > ground, but to a
 > buffered audio signal. Just an idea. This gives you
 > frequency modulation
 > / FM. Although, with the nonlinear impedance of the TC
 > secondary, this
 > direct FM is guaranteed to sound crappy, ranging from
 > "flat" to
 > highly distorted sound. :| However, correcting
comments
 > welcome! ;-)
 >
 >>>>>snip>>>>>>>>>>>>>>>>>
 >
 > regards,
 >
 >   - Jan
 >
 > --
 > ****************************************************
 >   Helsinki University of Technology
 >   Dept. of Electrical and Communications Engineering