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US 6,798,153 B2Granted
Method of regulating power in a high-intensity-discharge lamp
AssigneeKoninklijke Philips Electronics N.V.
InventorsCharles B. Mattas, Oscar J. Deurloo, Vincent J. Delia
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Abstract
A system and method of controlling power to a high-intensity-discharge lamp is provided. A voltage sensor determines voltage across the lamp. A current sensor determines current through the lamp. A control circuit approximates lamp power based on input from the sensors, compares the lamp power against a desired level, and regulates lamp power based on the comparison.
Claims20
A system of controlling power to a high-intensity-discharge lamp, said system comprising:
- a voltage sensor operable to generate a first sensing voltage indicative of a voltage across the lamp;
- a current sensor operable to generate a second sensing voltage indicative of a current through the lamp;
- and
- a control circuit operable to approximate a lamp power as a function of the first sensing voltage and the second sensing voltage, to compare the approximated lamp power and a reference voltage, and to regulate the power to the lamp based on the comparison of the approximated lamp power and the reference voltage,
- wherein said control circuit includes a summing circuit operable to generate a summation voltage as a function of a summation of the first sensing voltage and the second sensing voltage, the summation voltage being indicative of the approximated lamp power;
- wherein said voltage sensor is in electrical communication with said control circuit to apply the first sensing voltage to said control circuit, and
- wherein said current sensor is in electrical communication with said control circuit to apply the second sensing voltage to said control circuit.
4 more elements
A system controlling power to a high-intensity-discharge lamp, said system comprising:
- a voltage sensor operable to generate a first sensing voltage indicative of a voltage across the lamp;
- a current sensor operable to generate a second sensing voltage indicative of a current through the lamp;
- and
- a control circuit operable to approximate a lamp power as a function of the first sensing voltage and the second sensing voltage, to compare the approximated lamp power and a reference voltage, and to regulate the power to the lamp based on the comparison of the approximated lamp power and the reference voltage,
- wherein said voltage sensor is in electrical communication with said control circuit to apply the first sensing voltage to said control circuit, and
- wherein said current sensor is in electrical communication with said control circuit to apply the second sensing voltage to said control circuit,
- wherein said control circuit includes:
- a summing circuit operable to generate a summation voltage as a function of a summation of the first sensing voltage and the second sensing voltage, the summation voltage being indicative of the approximated lamp power;
- a reference generator operable to generate the reference voltage;
- and
- a comparator in electric communication with said summing circuit whereby the summation voltage is applied to said comparator and in electric communication with said reference generator whereby the reference voltage is applied to said comparator, said comparator operable to compare the summation voltage and the reference voltage to thereby generate a control voltage for regulating the power to the lamp.
8 more elements
A system of controlling power to a high-intensity-discharge lamp, said system comprising:
- a voltage sensor operable to generate a first sensing voltage indicative of a voltage across the lamp;
- a current sensor operable to generate a second sensing voltage indicative of a current through the lamp;
- and
- a control circuit operable to approximate a lamp power as a function of the first sensing voltage and the second sensing voltage, to compare the approximated lamp power and a reference voltage, and to regulate the power to the lamp based on the comparison of the approximated lamp power and the reference voltage,
- wherein said voltage sensor is in electrical communication with said control circuit to apply the first sensing voltage to said control circuit, and
- wherein said current sensor is in electrical communication with said control circuit to apply the second sensing voltage to said control circuit, wherein said control circuit includes:
- a signal conditioner operable to amplify the second sensing voltage;
- a summing circuit in electric communication with said signal conditioner whereby the amplified second sensing voltage is applied to said summing circuit, said summing circuit operable to generate a summation voltage as a function of a summation of the first sensing voltage and the amplified second sensing voltage, the summation voltage being indicative of the approximated lamp power;
- a reference generator operable to generate the reference voltage;
- and
- a comparator in electric communication with said summing circuit whereby the summation voltage is applied to said comparator and in electric communication with said reference generator whereby the reference voltage is applied to said comparator, said comparator operable to compare the summation voltage and the reference voltage to thereby generate a control voltage for regulating the power to the lamp.
8 more elements
A system of controlling power to a high-intensity-discharge lamp, said system comprising;
- a voltage sensor operable to generate a first sensing voltage indicative of a voltage across the lamp;
- a current sensor operable to generate a second sensing voltage indicative of a current through the lamp;
- and
- a control circuit including
- means for amplifying the second sensing signal,
- means for adding a first absolute value of the first sensing signal and a second absolute value of the amplified second sensing signal to thereby generate a summation voltage indicative of an approximated lamp power, and
- means for comparing the summation voltage to a reference voltage to thereby generate a control voltage for regulating the power of the lamp.
4 more elements
A system of controlling power to a high-intensity-discharge lamp, said system comprising:
- a voltage sensor operable to generate a first sensing voltage indicative of a voltage across the lamp;
- a current sensor operable to generate a second sensing voltage indicative of a current through the lamp;
- and
- a control circuit including
- means for amplifying the second sensing signal,
- means for adding a first average of the first sensing signal and a second average of the amplified second sensing signal to thereby generate a summation voltage indicative of an approximated lamp power;
- means for comparing the summation voltage to a reference voltage to thereby generate a comparison voltage for regulating the power of the lamp.
4 more elements
Dependencies are inferred from the claim text.