PFC for peak-rectified C-input power amp PSUs

[Quince]

How can power factor be improved in a non-switching power supply? I know a choke-input filter has better power factor than capacitor-input, but that's not an option for me as I simply don't have inductors of appropriate ratings. Any other methods, stuff on the primary side or something?

 

[Boswell]

Oddly enough, one way to improve the PF is to lower the value of the reservoir capacitor so that there is more ripple at that point. This spreads the charging current over more of the input cycle. You have to have enough volts in hand so you don't starve the regulators, and also you need to make sure your reservoir capacitors can take the extra current (a.c.).

 

[Svart]

ICs are available.. cheap but require more work.