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Old 24th April 2007, 11:05 AM   #131
Pierre is offline Pierre  France
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Sorry, I have reviewed my calculations and the Yorkville seems to switch at 70KHz.
The oscillator is U8, a 555 in astable multivibrator mode (resistors are both 1K, but the timing cap is C32, 6n8, while I had taken C80, 100nF, that is only a bypass cap).
(The sawtooth is not symmetrical at all, however: 9.4us vs 4.7us) I suppose that's compensated by feedback.
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Old 24th April 2007, 11:28 AM   #132
luka is offline luka  Slovenia
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Thats much much better
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Old 24th April 2007, 02:11 PM   #133
TOINO is offline TOINO  Portugal
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Voilą Pierre

And now friends?... should we help umut1001?
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Old 24th April 2007, 04:10 PM   #134
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Default hi ..ir2110 fullbridge

hi everybody..i bought many ir2110 ,1n4148 ,1n4007 ,bc546 and uf4007(ultra fast diode)..and i found a good and cheap toroid transformer but i didnt buy it is 60usa dollars ..made in italy and 33.6volts 16 amperes makes 47 volt dc..can i make a 250 watts of amplifier with that transformer?i think i can use 2 ohms load..and i want to buy lm311 or lm319 ..i do not know which one i prefer?i want to use lt1016 but i couldnt find lt1016 for comparating opamp..thanks
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Old 22nd May 2007, 03:51 PM   #135
luka is offline luka  Slovenia
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Hi SSassen

I see that you have some kind of power calculator for LTSpice, could you send me one?
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Old 19th May 2016, 07:51 PM   #136
kees52 is offline kees52  Netherlands
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Originally Posted by SSassen View Post
Alright, some more cool scope photos. This time around I followed a different line of reasoning, as when you're trying to limit overshoot at the output, who says that overshoot wasn't present on the input to begin with? So in this case you'd better try to fight the cause rather than the effect. Please refer to the below URL of the schematic these comments are in reference to:

SODFA class-D amplifier, revision 007

Overshoot comparator output
Click the image to open in full size.

The above image shows what signal the IR2011 MOSFET driver is fed with on pins 5 and 6. It is clear that there's a fair amount of, undesired, overshoot here which we need to get rid off, or at least minimize.

Overshoot integrator output
Click the image to open in full size.

The above image clearly shows that the integrator itself, 1/2 of the OPA2134, outputs quite some overshoot at pin 7. So what we're looking at here is overshoot that's introduced at an early stage in the amplifier and simply propagates throughout it. This could be crosstalk from the output section of course. For now I'm a bit puzzled on how to reduce or remove the overshoot at the comparator output or whether it is crosstalk or something generated in the amp itself.

Any helpful suggestions are most welcome!

Best regards,

Sander Sassen
Hardware Analysis - Computer hardware news, reviews and forums that provide help and assistance with problems.
Looks nice, I mean as a transmitter, class D are nice transmitters when do not pay attention about the demodulator coil.

Last edited by kees52; 19th May 2016 at 07:56 PM.
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Old 19th May 2016, 08:24 PM   #137
SSassen is offline SSassen  Netherlands
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C'mon, are you kidding me? This was a design I did almost 10 years ago (!) with a prototype on perforated board, on a proper double sided PCB this design shows much better behavior. The perforated board prototype was just a proof of concept.
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