Aleks
Member
Few days ago, I got 2 battery chargers to see if I can fix them. I'm currently working on one of them. They are both of the same type, Switch-Mode supplies. The power FETs (IRC840) are OK and so are the coils. As far as I can see, the FETs aren't getting activated and I can not measure any voltage after them. Their gates are connected via two ICs - "A T530 0721" which I believe to be opt-couplers to the output of a UC3525AN PWM IC.
Behind the PWM IC there are a whole bunch other components, like opamps (LM258), transistors, caps, resistors, and a relay at the output of the device.
I think that something is interfering with the pulse generation. Maybe its the PWM IC that is the cause or maybe something else, I really don't know and I don't know how can I test the PWM IC.
Can anyone give me any tips on how to debug the device even further and get to the source of the problem ?
Thanks in advance,
Aleks
Behind the PWM IC there are a whole bunch other components, like opamps (LM258), transistors, caps, resistors, and a relay at the output of the device.
I think that something is interfering with the pulse generation. Maybe its the PWM IC that is the cause or maybe something else, I really don't know and I don't know how can I test the PWM IC.
Can anyone give me any tips on how to debug the device even further and get to the source of the problem ?
Thanks in advance,
Aleks