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PFC and PWM Controller Operation on Phase Cut Line Input

Other Parts Discussed in Thread: UCC28521

Hello.  I have an application where I would like to use one of the PFC/PWM chips like the UCC28521 to develop a rail for a downstream process.  However, the product requires that the rail be available down to low phase angle (i.e. phase cut) AC input.  Has anyone any experience running such controllers on a phase cut line voltage or can anyone offer any suggestions on issues I should try and address to evaluate possible successful operation?  Thanks.

  • Hi David,

    Can the rail be supplied from the ac supply before the phase angle control is applied? I think that supplying the rail from the phase angle controlled waveform will be challenging.

    Can you tell how much power, volts/amps the rail needs to supply, does it require isolation?

    Thanks

    Peter
  • Hi Peter - thanks for the reply.  Unfortunately I have no access to the rail before the phase angle control is supplied, and the output does not require isolation.  Ideally the rail is about 50V at .8A, though if I had to deal with the usual 390V rail I could do so.

    Thanks again.