[Moved]: Sg3525 pwm changeover problem with ups

[fazalahad]

helo tahmed Salam
l have the same problem ( Sg3525 pwm problem and changeover problem)i have made a ups it warks fine but when electricity fails from grade it not starts quickly and so computer reboots.
i have remove the capacitor from softstart pin 8/ decrease the value of resistor which conect from pin 5to7. but no improvement.
please help me.

 

[ashad]

i have remove the capacitor from softstart pin 8/ decrease the value of resistor which conect from pin 5to7. but no improvement.
please help me.

Donot remove softstarting cap, you may use minimum value of capacitor to reduce the soft starting time. Check your switching circuit on transformer side, I am asking tab changing relay. I think u have some problem on switching side.

 

[fazalahad]

Thanks alot.
but ihave changed relay twice and i m sure tht is not the fault of relay .

 

[ashad]

Thanks alot.
but ihave changed relay twice and i m sure tht is not the fault of relay .

Sorry for late reply, I did not asked to replace the Relay, you may check the Relay switching circuit and probably sensing circuit which sense and switches the Relay.