PROBLEM TO BE SOLVED: To provide a ground fault detection circuit with which it is possible to detect a ground fault where a short-circuiting switch is not included in a ground fault path separately from a ground fault where the short-circuiting switch is included in the ground fault path.SOLUTION: A light-emitting device includes a serial connection member consisting of N light-emitting devices D1-D8, a light-emitting element drive circuit 1 having output terminal connected to the anode of the serial connection member, N short-circuiting switches Q1-Q8 each provided in parallel to each light-emitting element, and a switching control unit 3 for turning each of the short-circuiting switches on and off. A ground fault detection circuit, designed to detect a ground fault of the light-emitting device, includes a reference voltage source 7 for generating a reference voltage, and a comparator 6 for comparing the anode voltage of the serial connection member with the reference voltage. The reference voltage is smaller than the product of the ON resistance of one of the short-circuiting switches Q1-Q8 and the output current of the light-emitting element drive circuit 1.SELECTED DRAWING: Figure 1
【課題】短絡用スイッチを地絡経路に含む地絡と区別して短絡用スイッチを地絡経路に含まない地絡を検出することができる地絡検出回路を提供する。【解決手段】発光装置は、N個の発光素子D1〜D8から成る直列接続体と、前記直列接続体のアノードに出力端が接続される発光素子駆動回路1と、各々が各発光素子に並列に設けられるN個の短絡用スイッチQ1〜Q8と、各前記短絡用スイッチをオン/オフ制御するスイッチ制御部3と、を有する。地絡検出回路は、前記発光装置の地絡を検出する地絡検出回路であって、基準電圧を生成する基準電圧源7と、前記直列接続体のアノード電圧と前記基準電圧とを比較するコンパレータ6と、を有する。前記基準電圧は、短絡用スイッチQ1〜Q8のうち1個のオン抵抗と発光素子駆動回路1の出力電流との積より小さい。【選択図】図1
GROUND FAULT DETECTION CIRCUIT, ABNORMALITY DETECTION CIRCUIT, LIGHT-EMITTING DEVICE AND VEHICLE
地絡検出回路、異常検出回路、発光装置、車両
2017-11-16
Patent
Electronic Resource
Japanese
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 / G01R Messen elektrischer Größen , MEASURING ELECTRIC VARIABLES / H05B ELECTRIC HEATING , Elektrische Heizung |
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