A driver circuit for light-emitting diode (LED) headlight system includes a buck-boost converter connected in series to a first plurality of branches of LEDs. Each of the plurality of branches of LEDs includes a bypass switch configured to bypass the corresponding branch of LEDs. The buck-boost converter provides a constant current with an adjustable voltage to a selectable portion of the plurality of branches of LEDs, while bypassing each of the other branches of LEDs via the corresponding bypass switches. In some examples, the circuit delivers the current to the selectable portion of the first plurality of branches of LEDs during a first portion of a duty cycle, while delivering a digitally modulated current to a second plurality of branches during a second portion of the duty cycle.
Light-emitting diode headlight driver
2017-11-14
Patent
Elektronische Ressource
Englisch
IPC: | H05B ELECTRIC HEATING , Elektrische Heizung / B60Q ARRANGEMENT OF SIGNALLING OR LIGHTING DEVICES, THE MOUNTING OR SUPPORTING THEREOF OR CIRCUITS THEREFOR, FOR VEHICLES IN GENERAL , Anordnung von Signal- oder Beleuchtungsvorrichtungen, deren Einbau oder Halterung oder deren Schaltkreise bei Fahrzeugen allgemein |
Evaluation of After-Market Light Emitting Diode Headlight Bulbs
SAE Technical Papers | 2019
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