SwitcherMaze90
Newbie
Hello everybody. I am new member i am a berber from morocco with a diploma in industrial electronics repair and really happy to discover this board.
Ok back to the problem . I have an electronic welder with a pcb containing two switching circuits .
The main one is a 4 igbt half bridge configuration driven by an oscillator.
The second one is an auxiliary power supply that gives power to the main chopper , cooling fan and startup relay. It is based on a uc 3842 oscillator (empty circuit in the picture).
Now as far as i can see the problem is in the auxiliary circuit :
1) There is no stable Vcc voltage only fluctuating from 12v to 14 v.
2) There is no output signal from the oscillator.
Here is a picture of the auxiliary circuit with uc3842 , transformer and mosfet removed :
Ok back to the problem . I have an electronic welder with a pcb containing two switching circuits .
The main one is a 4 igbt half bridge configuration driven by an oscillator.
The second one is an auxiliary power supply that gives power to the main chopper , cooling fan and startup relay. It is based on a uc 3842 oscillator (empty circuit in the picture).
Now as far as i can see the problem is in the auxiliary circuit :
1) There is no stable Vcc voltage only fluctuating from 12v to 14 v.
2) There is no output signal from the oscillator.
Here is a picture of the auxiliary circuit with uc3842 , transformer and mosfet removed :