A lighting circuit drives a light source including plural light emitting elements and includes a bypass switch circuit which includes plural bypass switches connected in parallel with the plural light emitting elements, a boost converter which boosts a power supply voltage to generate a direct current voltage stabilized at a variable target voltage, a buck converter which receives the direct current voltage to supply a driving current stabilized at a target current to the light source and which includes a hysteresis controller configured to stabilize the driving current between a peak value and a bottom value and to change a difference between the peak value and the bottom value such a switching frequency of the buck converter approaches a constant value, and a voltage adjusting circuit which is configured to dynamically change the target voltage of the boost converter according to an output voltage of the buck converter.


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    Title :

    LIGHTING CIRCUIT AND VEHICLE LAMP


    Contributors:

    Publication date :

    2018-03-01


    Type of media :

    Patent


    Type of material :

    Electronic Resource


    Language :

    English


    Classification :

    IPC:    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 / H05B ELECTRIC HEATING , Elektrische Heizung





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