To limit a reduction in measurement accuracy of a capacitance value of a flowing capacitance connected in parallel to an insulation resistance in an electric leak detection circuit for detecting a drop in a resistance value of an insulation resistance between a ground line of a direct current power source installed on a vehicle and a vehicle body earth.SOLUTION: An electric leak detection circuit 1 comprises a floating capacitance measurement circuit 4 for acquiring without decay a voltage applied to a detection resistance Rd when a floating capacitance measurement oscillation signal Sc is output from an oscillation circuit 2, and a detection part 6 for measuring a capacitance value of a floating capacitance connected in parallel to an insulation resistance Rd based on a wave height value of the voltage V2 acquired by the floating capacitance measurement circuit 4 when the floating capacitance measurement oscillation signal Sc is output from the oscillation circuit 2.SELECTED DRAWING: Figure 1
【課題】車両に搭載される直流電源のグランドラインと車両のボディアースとの間の絶縁抵抗の抵抗値の低下を検知する漏電検知回路において、絶縁抵抗に並列接続される浮遊容量の容量値の測定精度の低下を抑える。【解決手段】発振回路2から浮遊容量測定用発振信号Scが出力されているときに検出抵抗Rdにかかる電圧を減衰せずに取得する浮遊容量測定回路4と、発振回路2から浮遊容量測定用発振信号Scが出力されているときに浮遊容量測定用回路4により取得される電圧V2の波高値により絶縁抵抗Rdに並列接続される浮遊容量の容量値を測定する検知部6とを備えて漏電検知回路1を構成する。【選択図】図1
ELECTRIC LEAK DETECTION CIRCUIT
漏電検知回路
2020-07-09
Patent
Electronic Resource
Japanese
IPC: | G01R Messen elektrischer Größen , MEASURING ELECTRIC VARIABLES / B60L PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES , Antrieb von elektrisch angetriebenen Fahrzeugen / H02J CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER , Schaltungsanordnungen oder Systeme für die Abgabe oder Verteilung elektrischer Leistung |
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