Flyback Driver and Plasma Speaker Driver Question?

I was looking for a good way to drive a flyback, and a circuit to make a Plasma Speaker.  What I came up with, can you use an MC12061 running at 3.8MHz through an IRF540 MOSFET to drive it?  If that works, could you make a summing amplifier with an Op Amp to sum the output of the MC12061 and the Audio (Maybe amplify the audio a bit before the summing amp?) before driving the MOSFET?  Would this work?  Would there be significant problems like heat dissipation from the MOSFET, distorted sound, etc?


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The coil's only designed to run in the 10s of Khz, you can't drive it at Mhz. Take a look at my Instructable on the flyback transformer for a detailed explanation.
Wesley666 (author)  steveastrouk4 years ago
Really? I am driving a monitor flyback, which I hear are driven around 100kHz for normal usage and after some Googling there is an Instructable that someone is running one at 2MHz. I had heard the faster you drive it, the better (To a point of course).

Other then that, say I had a replacement for the MC12061 that would allow me to drive it around 100kHz, does everything else sound like it would check out. Also, what is the normal human hearing range? Up to around 25kHz isn't it? As long as I drive it a bit above that you shouldn't hear the driving frequency correct?
Read the article. It explains clearly why you can't drive them faster.
Yes, above 25 k you should be OK.
Wesley666 (author)  steveastrouk4 years ago
Ok, makes sense. What is roughly the limit of the frequency they can be driven with? Again, other then toning down the frequency, would a summing amplifier work fine for adding audio?
Depends on supply volts - if you don't know the provenance of your coil, you're forced try it and measure the current in the primary. Then you can work it out, since you know the frame refresh rate and the horizontal resolution. refresh rate x resolution = line rate = drive frequency.