D-C Power supply circuit with high power factor
AssigneeLutron Electronics Co., Inc.
InventorDennis Capewell
Life of this patent
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Abstract
A d-c power supply is described which is energized from a relatively low frequency power source and produces a d-c output voltage with low ripple and high power factor. An inductance-capacitance circuit is connected in series with the a-c source and the a-c side of the rectifying element. A filter capacitor is connected to the d-c side of the rectifying element. The inductance-capacitance circuit resonates at a frequency of about three to six times the frequency of the input power supply. A plurality of circuits for carrying out the invention are disclosed.
Claims23
A high power factor power supply circuit comprising, in combination:
- an a-c supply circuit having a relatively low a-c frequency;
- a tuned circuit comprising an inductor and capacitor having respective values which are tuned to resonate at a frequency which is higher by less than about one order of magnitude than said relatively low a-c frequency;
- coupling means for connecting said a-c supply circuit to said tuned circuit;
- a rectifier means having a-c input means connected to said tuned circuit and having a d-c output circuit means;
- said inductor being connected in series with said rectifier means;
- said capacitor being connected in shunt with said rectifier means and having one terminal connected to the junction between said inductor and said rectifier means;
- and an output capacitor connected to said d-c output circuit means.
A power supply circuit having a high power factor;
- said circuit comprising, in combination:
- input a-c power terminal means for connection to an a-c source having a given frequency;
- a rectifier means having a-c and d-c terminals;
- an output capacitor connected across said rectifier means d-c terminals;
- an inductor connected between one of said a-c power terminals and one of said a-c terminals of said rectifier means;
- a second capacitor connected across said rectifier means a-c terminals;
- said inductor and said second capacitor being resonant at a frequency which is a multiple of about three to six times said given frequency;
- said output capacitor being substantially larger than said second capacitor.
A high power factor supply circuit comprising:
- a-c supply circuit means having any particular frequency;
- tuned circuit means including a capacitor means and inductor means resonant with one another at a frequency of from about three to six times said particular frequency;
- rectifier means having a-c input means connected to said tuned circuit means and having d-c output means;
- second capacitor means connected to said d-c output means;
- and output circuit means connected across said second capacitor means.
Dependencies are inferred from the claim text.