I am designing a 30V 5A power supply and after simulations working fine I decided to make it on actual hardware. But during the first run, something shorted and the power supply didn't even turn on.
These are before and after photos of PCB:
Photos (facing some issue on forum, so shared google drive link)
The black area on PCB is around the bridge rectifier. The bridge rectifier is shorted and some tracks have been removed due to high current(maybe). Other area on PCB is completely fine.
This is the whole schematic of power supply if required: link
The diodes used for bridge rectifier is RL207 (Datasheet) which has 2A 1000V rating and 70A surge current rating.
The max surge current according to the simulation is supposed to be around 20A which the RL207 should be able to handle even after derating.
Can anyone help me to find the actual problem?
The reasons that I could think of but not sure:
The residue flux after soldering shorted some tracks when 230VAC was connected. I had already verified all the connections using a multimeter before powering the circuit and orientation of diodes are also correct.
The inrush current was too high for diodes to handle during charging of 470uF capacitor due to which rectifier shorted and therefore AC mains got shorted.
Some extra information if required:
- Clearance for copper pour on PCB is 1mm.
- RL207 diodes were taken from an old computer power supply in working condition.
- NTC 10D-9 thermistor was also taken from the same old computer power supply.
- The yellow and black wire taped together was used in place of fuse as I didn't had any at that time.