HiperTFS power supply doesn't always start
Posted by: MarcoC
on
In a power supply 380Vdc input/ 24Vdc 8A output the TFS7702 doesn't start-up correctly. I don't use the standby flyback section, onley the main (forward) converter. Same time converter starts and run, other time converter start for some 100ms the turn off; There are no magnetics saturation, main tansformer or output inductance. Even if I force BP pin low (0V) then the behavioure is the same (can run or stop after about 100..200ms).
BP pin is supplied by an external 12V power supply that also powers the PFC controller (HiperPFS).
Does anyone have any ideas?
回應
Thank you for your reply. Here the schematic you asked for
| Attachment | 大小 |
|---|---|
| TFS7702 schematic (107.13 KB) | 107.13 KB |
Isn't one side of the transforrmer HV primary winding supposed to go to the HVDC in? the turn off snubber seems wrong ...
Hello MarcoC,
Thank you for interested in Power Integrations product.
Is it possible for you to paste the schematic and we can have a better understanding of your design. Then we can dig in more to find the root casue.
Best Regards