Firing of two thyristor

[Amod]

Kindly help me,iam not able to fire two thyristor using pwm.I searched for firing circuit on google but it is not working.I need to vary output voltage from 0 to full.

[Giuseppe MPO]

You can't use PWM to drive thyristors, the pulse to be sent must be in phase with the mains voltage.

[Amod]

Then how can i fire thyristor to regulate voltage from 0 to full.

[Giuseppe MPO]

You have to put a circuit that detects the crossing through zero and then have the PIC calculate the delay of the impulse to be given to the thyristor to send it into conduction.
Alternatively you can use a PIC that has a CIP peripheral with ZCD, like I did some time ago.

https://protoncompiler.com/index.php?msg=2045