The Hong Kong Polytechnic University

Dao Hong Wang

Bangalore Prabhakar Divakar

Ka Wai Eric Cheng

Chow Norbert Cheung

Eric Ka Wai Cheng

The present invention relates to temperature compensation of HID lamps in automobiles. The invention concerns the manner in which the temperature of the HID lamp is accounted for in order to drive the lamp is at appropriate power from hot to cold conditions. In the present invention, the voltage across a capacitor in the temperature compensation circuit is sensed and used as a command signal to anticipate lamp temperature, and accordingly the reference power to the HID lamp is modulated depending on the temperature of the lamp. In the present invention, the lamp is driven with a higher power setting when the lamp is cold and with lower power setting when hot. This adaptive generation of reference power setting depending on the temperature of the lamp is implemented using the voltage across a capacitor in the temperature compensation circuit.

HID ballast with integrated voltage multiplier and lamp temperature compensation

A system for automatically controlling power supply to a lamp () of a vehicle, the system comprising: a detection module () to detect whether the vehicle is stationary or non-stationary; a controller () to receive a signal () having a first value transmitted by the detection module () when the vehicle is detected as stationary, and the controller () to receive a signal () having a second value transmitted by the detection module () when the vehicle is detected as non-stationary, wherein if the signal () having the first value is received by the controller (), the controller () reduces the power supply to the lamp () from a first power level to a lower second power level in order to reduce energy consumption of the lamp (), and if the signal () having the second value is received by the controller (), the controller () restores the power supply to the lamp () from the lower second power level to the first power level.

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Hong Kong, China

Dao Hong Wang