thank for all help
now i am understand
Ok, i will change my program and now i will make the PWM switch the power in arbitary phase and automaticaly turn off when the power line in zero crosing. i have try some circuits. i have check my PWM and my Zero crosing detector. i check the ZCD and get 100hz frequently. but when i run my controler to check the heater driver, thats cant work. i change the heater with a 5watt lamp, but still not work. i try to set the pwm with some different duty cycle, 0%, 20%, 50%, 80%, 100%(full on peak), but the lamp stil not light.
for the information, i use PLC TWIDO TWDLMDA20DRT as my main controler. use PID as the algorithm.
at how frequenz of PWM i must use?
or maybe someone have tested firing phase circuit that can work good?
please i need help
best regards
jatayu