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Active PFC help needed

Hello,

I'm currently having some issues with the Power Factor of an Electronic design (please see attached image) and I was hoping you could aid me in
optimizing it.

Measuring the Power Facter (PF henceforth) on a power meter reveals a PF of only 0.17.
I have tried adding inductance in series with the circuit, but to no avail. PF has decreased if anything.

I tried measuring voltage and current from the wall socket to the device using an oscilloscope, to see an indication of the actual PF.
Images attached - please be advised: Current measurement is not to scale. Power meter estimated a current of 0.4A!
Voltage and phase is definitly out of phase, although a PF of 0.17 seems a bit low.

At this point I wanted to try adding active PFC to the circuit, namely a small circuit in the input of the two SMPSes. Unfortunately I have little to no idea of what kind of circuitry/IC is best used?
Or for that matter whether it will actually do any good in optimizing PF of the system?

Do you have some recommendations on designing a small circuit that will improve the Power Factor? Or any advise on generally improving PF?

Sincerely yours,
David Larsen

Combined.pdf
  • Hi David,
    Even if some solution is suggested for PFC for the SMPS's you already have, to make PFC and SMPS work together, you need to redesign the SCH and most importantly the PCB, so it would be better to select the new design in which you can use PFC based Flyback SMPS which directly provides the isolated Ouput with primary side regulation.
    TI has those solutions...

    regards,
    Narendra