Silvio
Well-known member
Dear Silvio,
I have built the SMPS, but the current limit circuit seems to be working incorrectly in my case. I have placed R10=4.7K and still it does not resist to a short circuit. Transistors get burned. Also, at about 2A load current, a few volts of peak-to-peak ripple appear on the output rail.
Are there any considerations about C10 capacitor? Maximum voltage, type?
Thank you and best regards,
Mihai
Hi Naminator200. The current limit is a current limit not a short circuit protection. This way if it is set correctly with the amplifier load it will also save the amplifier by limiting the voltage to its input. I also tried to short out the output in this smps and it did the same for me. If you want a short circuit protection then another method has to be used.
The voltage ripple is always present on high load. This also depend on the input capacitance ( the higher the better ) usually we use 1uF per watt across the 320v supply. This means if you have 2 capacitors rated at 200v X 470uF to form the half bridge. The capacitance value will be half because the capacitors are hooked in series. In this case 470 /2=235uf. The ripple voltage usually varies between 5 to 10%.