Striking and open lamp regulation for CCFL controller
First Claim
1. A method of igniting an unlit lamp comprising:
- generating a control voltage, wherein the control voltage has a first range of values for controlling duty cycle of driving signals that control power to the unlit lamp and a second range of values for controlling frequency of the driving signals; and
ramping the control voltage from a first level to a second level at a predefined rate to sequentially control a duty cycle sweep and a frequency sweep of the driving signals to provide an increasing output voltage to the unlit lamp while the output voltage across the unlit lamp is less than a predetermined level.
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Accused Products
Abstract
An apparatus and method for igniting a lamp during a strike mode of an inverter comprising: sequentially controlling a duty cycle sweep and a frequency sweep of driving signals in the inverter to provide an increasing output voltage to the lamp. One embodiment advantageously includes a closed feedback loop to implement the duty cycle sweep and the frequency sweep such that an open lamp voltage is reliably regulated during the strike mode. For example, the closed feedback loop stops the duty cycle sweep or the frequency sweep when the output voltage to the lamp reaches a predetermined threshold and makes adjustments to the duty cycle or frequency the driving signals as needed to keep the output voltage at approximately the predetermined threshold if the lamp has not ignited.
427 Citations
7 Claims
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1. A method of igniting an unlit lamp comprising:
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generating a control voltage, wherein the control voltage has a first range of values for controlling duty cycle of driving signals that control power to the unlit lamp and a second range of values for controlling frequency of the driving signals; and ramping the control voltage from a first level to a second level at a predefined rate to sequentially control a duty cycle sweep and a frequency sweep of the driving signals to provide an increasing output voltage to the unlit lamp while the output voltage across the unlit lamp is less than a predetermined level. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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Specification