DIRECT-CURRENT/VOLTAGE SWITCHING CIRCUIT FOR INSULATION RESISTANCE METER

摘要

PURPOSE:To output two kinds of double voltages as DC voltage outputs by providing a smoothing capacitor, a diode bridge circuit, and a switching relay contact. CONSTITUTION:When the switching relay contact 6 is on a side V1, the diode bridge circuit 5 and smoothing capacitor 4 operate as a full-wave rectifying circuit and an AC current ia from a point (a) flows to a point (b) through D1, C1, C2, D2, and V1 in order. Further, an AC current ib from the point (b) reaches the point (a) through V1, D3, C1, C2, and D4 and a DC voltage V0 is outputted to smoothing capacitors C1 and C2. When the contact 6 is connected to a side V2, the circuit 5 and capacitor 4 operate as a double voltage rectifying circuit, the AC current ia from the point (a) flows to the point (b) through D1, C1, and V2, and the AC current ib from the point (b) reaches the point (a) through V2, C2, and D4, so that the sum of C1 and C2 is outputted as a double voltage to V0.