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Posted: April 29, 2012 08:10 pm
Member No.: 36,713
Joined: April 29, 2012
I never succed with PIC programing, so I've assembled a schematic of a simple version pwm sine inverter.
I allready have few SG3524, so I did my schematic for this IC.
The oscillation frequency of the SG3524 in my schematic are 2.36 khz
I can even use one of my big standard EI silicon steel transformer for the output.
Anyones can look at my schematic and tell me if it would work ok ?
Here is the link to my schematic image:
This post has been edited by gaetan8888 on April 29, 2012 08:17 pm
Posted: April 29, 2012 11:59 pm
Forum Addict ++
Member No.: 73
Joined: July 24, 2002
Not even no.
Please read the SG3524 data sheet. In particular, observe how PWM is generated: the two outputs have equal pulse widths, so it is very difficult to use this chip to implement a class D amplifier. (It's not impossible to do so, but suffice it to say, there is no non-abusive method of using this chip.)
The "filtering" between switch and output transformer will result in avalanche failure of the transistors. Two fixes suggest themselves: 1. use full bridge instead of push-pull; 2. couple the filter inductors, so the opposing transistor's body diode acts as "catch" diode. The latter method has the shortcoming that leakage inductance will still result in overshoot and excessive ringing.
Finally, the feedback method shown would attempt to regulate DC output, based on the waveform peaks, but this would only work in a switching power supply. In an amplifier, all the feedback does as shown is introduce a DC bias, which is canceled by the push-pull output stage. In short, it does nothing.
Answering questions is a tricky subject to practice. Not due to the difficulty of formulating or locating answers, but due to the human inability of asking the right questions; a skill that, were one to possess, would put them in the "answering" category.
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