how to convert this circuit

[khatib]

how to convert this circuit (DC-AC CONVERTER),

I use PIC that out put PWM , so i need your help to convert this circuit to deal with pulse width modulation



thanks

 

[blueroomelectronics]

That circuit expects a 50% square wave. Why do you want PWM?

 

[khatib]

I USE PIC to do PWM not this osc

so .. how to connect 4 mosfet's with PIC

 

[blueroomelectronics]

Which PIC?

 

[khatib]

Pic 16f877

 

[blueroomelectronics]

A PIC with "Enhanced PWM Mode" will drive a 4 FET bridge. The 16F877 doesn't have one but other PICs do such as the 18F1320.

 

[khatib]

PIC 16f877 is not appropriate to do that ?

 

[blueroomelectronics]

Are you driving a motor (H-Bridge) or a transformer for a UPS?

 

[khatib]

transformer for UPS

 

[blueroomelectronics]

What's wrong with the circuit you posted? You don't need PWM.

 

[khatib]

It Is Not My Circuit , I Found It By Google
I Want Use It In My Project .. You Know ??


I USE PIC TO OUT MODULATED SINE WAVE ...OK?

 

[blueroomelectronics]

So use it, why do you think it needs PWM?

 

[khatib]

in UPS i use the PIC to control pulse width modulation for this circuit , i want UPS out put (modulated sine wave) so .. this circuit output square .. you know ?? i want it to out sine using pic .

thanks for you

 

[blueroomelectronics]

You could try PWM on IC1 pin 1.

 

[khatib]

thanks for you

 

[be80be]

He doesn't need PWM back in the day thay would use a relay make it vibrate at 60hz use that to feed a step up transformer 12v to 100 use that to power the radio in a car. Then
came the big metal transistors you make a bridge and a oscillator to switch at 60hz you have the same thing but you can't hear it while your radio is playing a song.

You could try PWM on IC1 pin 1.
__________________

That the start of the switching part of the circuit looks like to me it would work better if you oscillated a pin at 60hz

 

[shingadaddy]

Hm. Circuit reminds me of an Alternator-battery charge tester / FET destroyer / Random RF generator / FUSE pop tester. No bleed offs on the gates. Brute force TTL or CMOS timing. I believe you have to get those specific FET's at the IDEAL FET store.

 

[blueroomelectronics]

Hm. Circuit reminds me of an Alternator-battery charge tester / FET destroyer / Random RF generator / FUSE pop tester. No bleed offs on the gates. Brute force TTL or CMOS timing. I believe you have to get those specific FET's at the IDEAL FET store.

I'm sure it will demonstrate those functions just fine.

I don't have the link handy but the schematic appears to be from a Japanese site that featured really overly complex circuits. Like the LED sign with a small PIC and a pair of FPGAs!!

 

[shingadaddy]

That sign might be a candidate for the Rube Goldberg award

 

[be80be]

Wouldn't the transformer have a lot of emf