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April 10, 2025
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Questions about to Auxiliary power supply with VIPER06

  • April 10, 2025
  • 1 reply
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Hi

I have a question about the conection of VIPER06 module as auxiliary power supply.  I Have a power stage PFC with L6562  and two capacitor in series as outuput capacitor. Then, i need a 15V aux power supply. Can i connect the VIPER06 Flyback stage, from the middle point of output capacitors of the PFC?

Looks like this...

mcolin_0-1744305849952.png

 

Best answer by Peter BENSCH

Welcome @mcolin, to the community!

You have probably connected the two capacitors in series to divide the voltage between them so that each sees (approximately) the same voltage, right?
The halving only works with halfway identical capacitors, which is usually guaranteed with the same batch, but should actually be balanced by equalising resistors connected in parallel.

By connecting external circuits such as this flyback converter with VIPER06, however, you would completely confuse this voltage halving and considerably increase the voltage at the upper partial capacitor.

In my opinion, you must connect the flyback to the full voltage. If this voltage is too high, you could select a VIPER with a higher voltage rating or set up a cascode circuit.

Hope that helps?

Regards
/Peter

1 reply

Peter BENSCH
Peter BENSCHBest answer
Technical Moderator
April 10, 2025

Welcome @mcolin, to the community!

You have probably connected the two capacitors in series to divide the voltage between them so that each sees (approximately) the same voltage, right?
The halving only works with halfway identical capacitors, which is usually guaranteed with the same batch, but should actually be balanced by equalising resistors connected in parallel.

By connecting external circuits such as this flyback converter with VIPER06, however, you would completely confuse this voltage halving and considerably increase the voltage at the upper partial capacitor.

In my opinion, you must connect the flyback to the full voltage. If this voltage is too high, you could select a VIPER with a higher voltage rating or set up a cascode circuit.

Hope that helps?

Regards
/Peter