Constant power switching power supply
First Claim
1. Apparatus for delivering DC electrical power at a constant rate to continuously operating load means comprising:
- a. means for generating a series of spaced, generally sawtooth shaped waves;
b. means for initiating said waves at a predetermined unvarying frequency;
c. means in response to the peak current reached by said waves to terminate said pulses at times so as to maintain a preselected peak current; and
d. means for delivering the electrical energy in said sawtooth waves to said load means during the periods of time between said sawtooth waves, said power being delivered to said load means being thereby maintained at a constant, predetermined level irrespective of variations in line voltage and impedance of said load means.
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Accused Products
Abstract
A power supply for a gaseous discharge lamp in which power adjustments are made automatically to insure that rated lamp power is delivered regardless of changes in lamp impedance or line voltage which may occur. A high D.C. voltage is delivered to a step down low hysteresis transformer and electronic switching is provided to obtain a high frequency pulsed flow to the primary of the transformer. Sawtooth waves are generated and peak current is utilized to regulate closely power input to the transformer. A feature is the use of a programming resistor to select the desired power level for the particular gas discharge lamp.
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Citations
10 Claims
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1. Apparatus for delivering DC electrical power at a constant rate to continuously operating load means comprising:
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a. means for generating a series of spaced, generally sawtooth shaped waves; b. means for initiating said waves at a predetermined unvarying frequency; c. means in response to the peak current reached by said waves to terminate said pulses at times so as to maintain a preselected peak current; and d. means for delivering the electrical energy in said sawtooth waves to said load means during the periods of time between said sawtooth waves, said power being delivered to said load means being thereby maintained at a constant, predetermined level irrespective of variations in line voltage and impedance of said load means. - View Dependent Claims (2, 3, 4)
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5. A circuit for delivering DC electrical power at a constant rate to continuously operating load means comprising:
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a. a source of DC; b. transformer means whose primary receives said DC; c. electronic switching means for interrupting said DC to produce generally sawtooth shaped spared waves passing through said primary; d. current sensing means for measuring current growth of said sawtooth waves in said primary; e. means for producing at a constant frequency pulses whose width is a function of peak current reached by said sawtooth waves, each of said pulses being initiated at an unvarying repetition rate; f. driver means for closing said electronic switch means at the initiation of each said pulses at a constant frequency and opening said electronic switch means in response to said pulse width so as effectively to maintain a constant current peak current reached by said sawtooth waves; g. said transformer means having a secondary in which current flows when the magnetic field in said transformer means collapses as a result of the opening of said electronic switch means; and h. means for delivering the output of said secondary to said load means, said power thereby being held at a constant, predetermined level irrespective of changes in line voltage and impedance of said load means. - View Dependent Claims (6, 7, 8, 9, 10)
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Specification