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change amplitude of Sinewave from pwm

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ismu

ismu

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Hai..friends

from given picture 5v(20ms period) pwm wave converted to sinwave and which trigger mosfet to get 12v sinwave from 12v dc ,which is given to primary of transformer and o/p is 220v ac sinwave (20ms period).

But
how can i change amplitude of o/p by changing Pwm (what change required),without changing transfmr tapping.
................................................................................................................................. .
please draw the wave form to visualize how pwm change amplitude of o/p.:cry:
 

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I think you diagram is simplyfied too much, you definitely have a energy storage on your 5V side to make the square PWM a bit "rounder". then by changing the duty-cycle of the PWM you can change the waveform that drives the gate of your MOS-FET. (At 100% dutycyle you will have DC and your transformer won't work anymore)
But you will never have a true sine-wave anywhere, at best something that look similar.
I don't think a discrete setup with a transformer is not the way to go. Look up some other "Power Electronic" Circuits. seach google for "boost-converter"

Best regards
Thomas
 
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    ismu

    ismu

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You may want to try some circuit simulation tool and find out the stuff your self. This may be useful for you as circuit details are not very complete. You can download free tools like pspice etc from web.

Looking at this circuit, it does not look like that controlling PWM would directly control the output voltage. One need to see L & C used in this circuit.
 
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    ismu

    ismu

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sir.
you are current.
but dutycycle depend to get shap of sine wave. but i want to know how will o/p of transformer can vary (wat the diiference b/w the triger pwm if o/p is 220v and 110v--both are sine wave at diffrent amplitue) i heared pwm can change o/p wave form shape, frequnecy, amplitue,charging current. but how can change amplitude?
 

If you read this careful , you should find the idea....................

Class D Audio Amplifiers - Theory and Design
**broken link removed**
 
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