Re: continuous mode,current mode control, boost circuit

On Tue, 19 Feb 2008 09:03:47 -0800 (PST), reggie
<veggiedom@xxxxxxxxxxxxxx> wrote:


I in effect want to understand how the ripple is produced, not just to
assume it's the shape of the waveform in the application note.

I don't understand:

a) the phase relationship between the mains sine wave and the boost
ripple voltage

The pfc is designed to draw sinusoidal currents from the line. The LF
ripple voltage on the LF bulk caps can be assumed to be 120Hz lagging.

b) the amplitude of the ripple due to the boost circuit (however know
the ESR of the capacitor has an in pact on this)

HF ripple current is created by both the boost source and any HF
switched load. The resulting voltage depends on extent of HF
decoupling and degree of synchronization attempted.

c) how to derive/understand the equation Igain=(Iac*veao)/Vrms^2

I'd have to know where the formula is pulled from before attempting to
figure out what the author intended to convey. Igain, by itself, has
no inherent meaning or sense.


RL
.