RE: SSTC Singing Arc Design - Help needed CLASS D IMPLEMENTATION

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

Original poster: "Mccauley, Daniel H by way of Terry Fritz <twftesla-at-qwest-dot-net>" <daniel.h.mccauley-at-lmco-dot-com>


>>>>Okay, i think you convinced me to scrap the TL494. 

Let me see if I have this correct.  Please correct me if I am wrong or if I
am missing something.

1.  I should use a 555 or 556 timer IC to generate a sawtooth (which is
present at the capacitor terminal of 555) at
the RESONANT FREQUENCY of my secondary coil.  So for me, I need a sawtooth
waveform at 200kHz.

2.  I then feed my audio signal into a comparator with the sawtooth signal
and I should get a PWM waveform out at the frequency set by my sawtooth
waveform.

QUESTION>>>>>>>>>>>  Is there any particular way to bias these signals???
For example if my sawtooth waveform varies from 0 to 5V, should my audio
signal be centered within that range or doesn't this matter.  Also, how
should one set the amplitude (threshold) for the sawtooth wave (or is this
just adjusted to get the best audio quality during running)

3.  I then can use the comparator output (say using a pull-up resistor on
the output at 5V) to get a PWM pulse from 0 to 5V which can then be fed into
my MOSFET 4421/4422 drivers.

Any help appreciated.

Thanks again for the help!!!

Dan