I am having a trouble with a mains rectifier. Simplified schematic:
Only problem I have is that R1 sometime explodes during circuit power-up. It happens when C1 is discharged, and there is a 310v peak in input.
Due to resistive nature of capacitor charge, same amount of energy as stored in capacitor (~50mJ) should be dissipated somwhere else
The simple solution is to whack a giant 2W resistor, capable of withstanding high energy pulses, but I am having a limited space. Also, if I remove a resistor, then fuse will blow up
I would like to use a few 0805 in a row, but they explode sometimes.
I assume that this is due to the fact that metal film is extremely thin and not capable of holding a significant amount of energy. Carbon film should be better.
How this problem is solved in modern PSU? Is there some special resistors available?