Fixed frequency Hysteretic Control

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Blah blah.

Anyway, Buyer beware! I really really really know that this will mess up when it hits the stops (clips) so I'll have to waste some time working out how to avoid the burps and farts.

It's an LTspice analysis.....

Here we go, 2, 3, 26.47

http://80.6.211.54/diyaudio/stuff/ideal.gif

That's using Ideal switches.

http://80.6.211.54/diyaudio/stuff/IRF(9)640.gif

That's using an IRF640 and IRF9640 model from International Rectifier.

Half bridge, +/-50V rails, 60W into 4R. 333.33KHz switching frequency.

That's to match quoted figures from the IRF amplifier.

Post filter feedback.

(Note for lazy **** me, edit for link)

Aha...!

http://www.irf.com/technical-info/refdesigns/iraudamp4.pdf

Both of them work out to be 0.0015% (ish) third harmonic distortion. I don't doubt that if I built one things would be worse.

Obviously it uses a 'dual pre-emptive' phase locked loop.

Like it looks in the piccies things are 'rock solid' on the switching frequency side of things. Honest Jim, this is hysteretic control.

Not wishing to give any games away you can see the 'hash' around 25KHz where the PLL section crosses over. Still haven't figured out the gain stuff for that bit. (should have been 40KHz)

Jacka Wackaman would probably have some inaccessible links to the IEEE for this stuff which might be the difference between original thinking and library search person.

Chris would be bonking on about doing it the Hypex way without knowing how it was really done.

Bruno might know what the transfer function of his circuit is but that's probably proprietry information. (Actually he doesn't, life is a wob)

Tra La La La La....

DNA
 
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