To suppress an unnecessary reduction in brightness of a semiconductor light source.SOLUTION: A semiconductor light source 502 includes a plurality of light emitting elements 504_1-504_3 connected in series. A drive circuit 610 receives an input voltage Vand supplies a drive current Ito the semiconductor light source 502. A bypass circuit 620 is connected to at least one light emitting element (504_3) of the plurality of light emitting elements 504_1-504_3, and is brought into an enable state based on the relationship between the input voltage Vand a threshold Vhaving a negative correlation with the temperature of the semiconductor light source 502 thereby to bypass the drive current I.SELECTED DRAWING: Figure 2
【課題】半導体光源の輝度の不要な低下を抑制できる。【解決手段】半導体光源502は、直列に接続される複数の発光素子504_1〜504_3を含む。駆動回路610は、入力電圧VINを受け、半導体光源502に駆動電流ILEDを供給する。バイパス回路620は、複数の発光素子504_1〜504_3の少なくともひとつ(504_3)と接続され、半導体光源502の温度と負の相関を有するしきい値VTHと入力電圧VINとの関係にもとづいてイネーブル状態となり、駆動電流ILEDを迂回させる。【選択図】図2
LIGHTING CIRCUIT AND VEHICLE LIGHTING FIXTURE
点灯回路および車両用灯具
23.01.2020
Patent
Elektronische Ressource
Japanisch
IPC: | F21S Ortsfeste Leuchten , NON-PORTABLE LIGHTING DEVICES / 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 |