General Electric Company

Chenghua Zhu

Gang Yao

Xuefei Xie

Bo Zhang

The present disclosure thus provides a technique for providing multi-level operation of ballast circuitry for discharge lamps. In one version, an auxiliary capacitance is switched in and out of circuit by a user controlled switch for lower the frequency of the voltage from the inverter to the transformer resulting in lower power output to the lamps. In another version, the auxiliary capacitance may be switched in and out of circuit by a user operated switch wherein the capacitance is connected to the secondary or output winding of the transformer for selectively reducing power to the lamps for reduced illumination. In other versions, auxiliary inductances are selectively switched in and out of circuit to alter the frequency of the primary voltage to the transformer. In another version, an auxiliary winding is selectively switched in and out of the secondary of the transformer for providing normal and reduced level power to the lamps. In another version, a variable direct current power supply is provided to the coupled inductors of the ballast circuitry for user control of the power supply to the ballast circuitry.

Changing power input to a gas discharge lamp

An electronic ballast circuit having at least two distinct switching cycles also includes an anti-striation feature. More particularly the electronic ballast includes an input section configured to receive an input from a power source. A resonant section receives the signals from the input section in order to generate a resonant signal. An anti-striation component is connected within the electronic ballast circuit to affect operation of the resonant section, which results in an affected resonant signal. A switching arrangement is configured to receive the affected resonant signal from the resonant section and anti-striation component, and is further configured to generate an asymmetric output signal due to the affects of the anti-resonant component, wherein the anti-striation component causes parameters of the resonant section of the electronic ballast circuit to be different for different switching cycles of the electronic ballast circuit. An output section is provided to output the asymmetric output signal to a lamp system.

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Shanghai, China

Chenghua Zhu