In Reply to: RE: Tell me, Deathtube posted by op48no1 on March 18, 2012 at 19:55:50:
I have demonstrated by analysis, simulation, and direct measurement that the first stage of a "flywheel" filter has a special property that significantly improves the DC regulation of the supply while avoiding many of the problems of both traditional cap- and choke-input filters.So much for the narrow-minded EEs who keep saying the damned thing can't possibly work.
-Henry
And I took it a bit farther and discovered that the exact same results can be had by either the "flywheel" small choke in series with the filter input OR the popular small capacitor in parallel with the filter input.
i.e. either small value series L input or small value parallel C input will, if proper values are chosen, accomplish the EXACT SAME RESULT of higher output voltage vs a critical-L input filter and lower filter impedance compared with a more conventional C input filter.
The principle is very simple. The filter input stage is tuned to a resonant frequency of either 2X or 3X the ripple frequency (for 60 Hz mains that works out to 240 Hz or 360 Hz. When this is done properly, the input stage of the filter stores energy during the period the rectifier is supplying current (conduction phase) and releases it during the time between rectifier current pulses. The result is GREATER RECTIFIER CONDUCTION ANGLE and lower impedance vs. a C-input filter.
it's really that simple. And it works. And it's a perfectly fine way of building a power supply filter.
Edits: 03/24/12
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Follow Ups
- RE: Tell me, Deathtube - Michael Koster 07:16:42 03/24/12 (0)