Control Unit for a Lamp Driver Providing Smooth Transition Between Operation Modes
First Claim
1. A control unit for a lamp driver being adapted to control the operation of a lamp during at least an ignition mode, a run-up mode and a normal operation mode, the control unit comprising:
- means for providing, initially in an ignition mode, a predetermined start value of current to the lamp,means for, subsequently in the ignition mode, increasing the provided current to a predetermined maximum value.
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Accused Products
Abstract
A control unit for a lamp driver for controlling a lamp during various operation modes. Current through the lamp is increased, preferably linearly, during ignition mode from a first start value to a maximum value. The lamp starts up smoothly and warms up already in ignition mode. Leads to higher lamp voltage and improved switching behavior. May be further improved by changing the duty cycle of a down-converter in order to obtain commutation. May be even further improved by maintaining an alternator running at high frequency (>I 00 kHz) during run-up mode.
29 Citations
12 Claims
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1. A control unit for a lamp driver being adapted to control the operation of a lamp during at least an ignition mode, a run-up mode and a normal operation mode, the control unit comprising:
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means for providing, initially in an ignition mode, a predetermined start value of current to the lamp, means for, subsequently in the ignition mode, increasing the provided current to a predetermined maximum value. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method for controlling a lamp driver during at least an ignition mode, a run-up mode and a normal operation mode, the method comprising the steps of:
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providing, initially in an ignition mode, a predetermined start value of current to the lamp, subsequently in the ignition mode increasing the provided current to a predetermined maximum value.
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Specification