26 Apr
2011
26 Apr
'11
6:41 p.m.
On Tue, 26 Apr 2011 20:05:21 -0400, Dave McGuire wrote:
I'd like to see the math on that. I have a
pretty good grasp of
switching regulators; I've done a lot with them in various designs.
Admittedly only very small ones for portable equipment though, in the
sub-1A range, but the concepts are the same. PWM a transistor between
saturation and cutoff, smooth it out with a capacitor, sample the output
into an error amplifier to control the PWM duty cycle. No load there,
unless you're talking about leakage across the PCB and such.
Ohm's law comes unglued when R goes to infinity.
Capacitive reactance comes into play, maybe thats enough load?
But an RC circuit with infinate R will always seek the peek voltage of the pulse,
no matter the freq untill there is some load to regulate around.
The other Bob