Ballast with temperature compensation
AssigneeGeneral Electric Company
InventorsHongbin Wei, Gang Yao, David Zhang
Life of this patent
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Abstract
A ballast for driving a gas discharge lamp includes an inverter configured to generate a lamp supply voltage signal, and a voltage regulator coupled to the inverter and configured to generate a regulation signal. The regulation signal is used by the inverter to maintain the lamp voltage signal at a substantially constant voltage. A thermistor circuit is coupled between the lamp supply voltage signal and the voltage regulator and configured to detect a temperature of the ballast. The lamp supply voltage signal is varied by the regulation signal in accordance with the detected temperature of the ballast.
Claims20
A ballast for driving a gas discharge lamp, the ballast comprising:
- an inverter configured to generate a lamp supply voltage signal;
- a voltage regulator coupled to the inverter and configured to generate a regulation signal, the regulation signal being used by the inverter to adjust the lamp voltage signal;
- and
- a thermistor circuit coupled between the lamp supply voltage signal and the voltage regulator and configured to detect a temperature by the thermistor circuit and vary the regulation signal, the lamp supply voltage signal being varied by the regulation signal in accordance with the detected temperature by the thermistor circuit.
An electric lighting apparatus, the apparatus comprising:
- an inverter configured to produce a lamp supply voltage;
- a lamp load coupled to the lamp supply voltage, the lamp load comprising one or more gas discharge lamps;
- and
- a feedback regulator coupled to the inverter, the feedback regulator being configured to generate a regulation signal that is used by the inverter to maintain the lamp supply voltage at a substantially constant voltage,
- wherein the feedback regulator comprises:
- a first feedback circuit coupled to the a return side of the lamp load and configured to generate a first feedback voltage signal;
- an error amplifier coupled to the first feedback voltage signal and configured to generate the regulation signal;
- and
- a first thermistor circuit coupled between the return side of the lamp load and the first feedback circuit,
- wherein the first thermistor circuit is configured to adjust the first feedback voltage signal to vary the lamp supply voltage according to a temperature detected by the thermistor circuit.
A method for providing temperature compensation in a lighting apparatus wherein the lighting apparatus comprises an inverter to provide a lamp supply voltage, a lamp load driven by the lamp supply voltage, and a feedback circuit to regulate the lamp supply voltage, the method comprising:
- detecting a supply side signal from the lamp load, the supply side signal comprising information on the lamp supply voltage;
- adjusting a first feedback gain in the feedback circuit using a first thermistor, the first feedback gain being dependent upon a temperature detected by the first thermistor;
- applying the first feedback gain to the supply side signal to create a first feedback signal;
- generating an error signal in the feedback circuit based at least in part on the first feedback signal;
- and
- regulating the lamp supply voltage generated by the inverter according to the error signal.
A method for providing temperature compensation in a lighting apparatus wherein the lighting apparatus comprises an inverter to provide a lamp supply voltage, a lamp load driven by the lamp supply voltage, and a feedback circuit to regulate the lamp supply voltage, the method comprising:
- detecting a return side signal from the lamp load, the return side signal comprising information on a return side of the lamp load;
- adjusting a first feedback gain in the feedback circuit using a first thermistor, the first feedback gain being dependent upon a temperature detected by the first thermistor;
- applying the first feedback gain to the supply side signal to create a first feedback signal;
- generating an error signal in the feedback circuit based at least in part on the first feedback signal;
- and
- regulating the lamp supply voltage generated by the inverter according to the error signal.
Dependencies are inferred from the claim text.