Hello everyone i m trying to set the duty cycle of a SG3525 with a optocoupler but on this design there is no pwm! the circuit without the sg 3525 are ok!
just trying to understand where the problem come through!
thanks for comments!

 

It works:

 

Hello danko your view attachment cant be found!
thank you

 

Hello everyone i m trying to set the duty cycle of a SG3525 with a optocoupler but on this design there is no pwm! the circuit without the sg 3525 are ok!
just trying to understand where the problem come through!
thanks for comments!

The pull-down resistor on pin 2 is missing.

 

OK good thank you

 

Hello everybody ive tested dankos schematic and the duty cycle works from 49% to 39% i really dont know where the problem is located! the input of the 4N35 is 0vdc to 30 vdc
regards!

 

the input of the 4N35 is 0vdc to 30 vdc

I hope you had a series current-limiting resistor? If not, the 4N35 is probably toast.

 

yes i have a 570ohms resistor!

 

Hello everybody ive tested dankos schematic and the duty cycle works from 49% to 39% i really dont know where the problem is located! the input of the 4N35 is 0vdc to 30 vdc
regards!

PWM range on pin 11 and pin 14 is 0-50%, and can not be more!

yes i have a 570ohms resistor!