topswitch clamp overheating
Hi,
I've designed a 24V 3.5A power supply using PI Expert. After assembling the prototype I found the clamp is overheating. After about 20-30sec the TVS diode fails at full power. I measured the primary leakage inductance and it's around 8uH with all other windings shorted. The result from PI Expert was 5uH. The other thing I noticed is that the bias output voltage at full power is around 37V. This seems pretty high. I tried increasing the snubber capacitor on the primary as well as adding another 24k resistor in parallel but the TVS diode is still overheating. The schematic is attached.
Regards,
Comments
Hi,
Can I email you the design files?
Regards
Double click in my user logo and choose private message to send me an email
I am trying to do the same. To send you a private email but somehow I can not do it. I need to check with administration to fix this issue. In the main time tell me if you can send it to me.
Thank you PI-Worf
Could you please post your PI exper file? I wan to take a look to your IDRAIN Peak. Also I like to see your transformer design.
Are you following the PCB layout recomended by PI expert?
Is the over heating happening at Low line(minimum input voltage)
Can you do something to test the power supply?
Turn it on at Low line. load it 10% and 20% of full load. meaure POUT and PIN and calculate the Efficency . let me know what are the results
PI-Worf