Full digital dimming ballast for a fluorescent lamp
First Claim
1. A lamp-control circuit, comprising:
- a power factor corrector;
a digitally controlled ballast, comprising power devices and coupled to the power factor corrector, the ballast operable to power a lamp;
a current feedback loop, coupled between at least one of the power devices and the digitally controlled ballast, configured to provide a current feedback signal; and
a voltage feedback loop, coupled between the lamp and the digitally controlled ballast, configured to provide a voltage feedback signal, whereinthe digitally controlled ballast is configured;
to generate a counter signal in accordance with increasing counter values; and
to generate a control voltage, therebygenerating a pulse frequency modulated control signal in response to at least one of the current feedback signal and the voltage feedback signal.
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Accused Products
Abstract
A lamp control circuit is described, containing a power factor corrector, coupled to it a digitally controlled ballast, having power devices. The digitally controlled ballast is capable of powering a lamp. The ballast is controlled by a current feedback loop, coupled between the power devices and the digitally controlled ballast, and a voltage feedback loop, coupled between the lamp and the digitally controlled ballast. Further, a method of operating a lamp-control circuit is presented, the circuit containing a digital controller, an output stage, a current feedback loop, and a voltage feedback loop. In operation the digital controller receives a current feedback signal or a voltage feedback signal from the output stage and the lamp. In response to the received signal the digital controller generates a digital control signal and powers a lamp through the output stage according to the generated digital control signal.
55 Citations
26 Claims
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1. A lamp-control circuit, comprising:
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a power factor corrector; a digitally controlled ballast, comprising power devices and coupled to the power factor corrector, the ballast operable to power a lamp; a current feedback loop, coupled between at least one of the power devices and the digitally controlled ballast, configured to provide a current feedback signal; and a voltage feedback loop, coupled between the lamp and the digitally controlled ballast, configured to provide a voltage feedback signal, wherein the digitally controlled ballast is configured; to generate a counter signal in accordance with increasing counter values; and to generate a control voltage, thereby generating a pulse frequency modulated control signal in response to at least one of the current feedback signal and the voltage feedback signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method of operating a lamp-control circuit, the circuit comprising a digital controller, an output stage, a current feedback loop, and a voltage feedback loop, the method comprising:
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receiving one of a current feedback signal and a voltage feedback signal by the digital controller; generating a digital control signal in response to the received signal by the digital controller, comprising; generating a counter signal in accordance with increasing counter values; and generating a control voltage, thereby generating a pulse frequency modulated control signal by the digital controller; and powering a lamp by the output stage according to the generated digital control signal. - View Dependent Claims (16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
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Specification