# Please need help for sine wave inverter.

Discussion in 'The Projects Forum' started by Muzamil Farid, Nov 24, 2015.

1. ### Muzamil Farid Thread Starter New Member

Nov 24, 2015
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I am working on sine wave inverter and i really need serious help,It will be heavily appreciated, I am controlling H-bridge(High side P channel,Low side N-channel) via SPWM signals and 50HZ Square Pulses.The first leg controlled by SPWM and other leg controlled by 50HZ square waves, I am confused about the functioning of P-channel Mosfets, How are they conducting?.What is the criteria of conduction? The source of high side p mosfets is 12V dc to be converted to 220V,50Hz sine wave,My confusion is that output distorted Sine wave will have a peak of 12V?. After implementing on proteus I am getting 0v between two outputs of H-bridge.

2. ### Dodgydave Distinguished Member

Jun 22, 2012
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So am i confused, your using square waves making a sine wave, lets have a circuit diagram please....

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3. ### Muzamil Farid Thread Starter New Member

Nov 24, 2015
4
2
Thanks for the reply, Actually i surveyed on the internet and found the designs using 50HZ Sqaure waves on the right leg of bridge, I am obtaining Sine waves from SPWM control signals,The only explanation i could find of using 50HZ Sqaure wave was that it controls polarity and PWM signal controls amplitude of output wave,I

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4. ### alfacliff Well-Known Member

Dec 13, 2013
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yes the output will be 12 volt square aves. a transformer is used to step up the voltage to the out put you want.

5. ### Dodgydave Distinguished Member

Jun 22, 2012
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Is L1 a transformer?, if so the secondary winding is not drawn, that will step up the voltage to 220V ac, or whatever its designed to give out, dont see the point of C1 .

6. ### Muzamil Farid Thread Starter New Member

Nov 24, 2015
4
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L1 is the inductor used with C1 as low pass filter to remove unwabted harmonics from output

7. ### Dodgydave Distinguished Member

Jun 22, 2012
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L1 is in the wrong place, it should be in series with the positive supply.

8. ### Muzamil Farid Thread Starter New Member

Nov 24, 2015
4
2
I dont understand where in series, from positive supply to capacitor and then measure output at node of capacitor?

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