GROUND FAULT DETECTION APPARATUS
FIG2 is a diagram illustrating another example of an arrangement place of a positive-electrode-side C contact switch
In the aforementioned embodiments, the common contact c of the positive-electrode-side C contact switch 111 is connected to the detection capacitor C1 via the parallel circuit of the path of the diode D1 and the resistor R1 and the path of the resistor R2 and the diode D2, but, as illustrated in FIG2, the common contact c of the positive-electrode-side C contact switch 111 may be directly connected to the detection capacitor C1. In this case, it is sufficient that the contact a is connected to the resistor Ra via the diode D1 and the resistor R1, the contact b is connected to the switching element Sa via the diode D2 and the resistor R2, and the path of the diode D2 and the path of the diode D11 whose direction is opposite to that of the diode D2 and the resistor R11 are connected in parallel to each other.
diagram
300
high-voltage battery
100
ground fault detection apparatus
302
negative-electrode-side power supply line
120
control device
['1. A ground fault detection apparatus that is connected to a non-grounded high-voltage battery (300) and detects a ground fault of a system provided with the high-voltage battery, the ground fault detection apparatus comprising: a control unit (120); a detection capacitor (C1) that operates as a flying capacitor; a positive-electrode-side first resistor (Ra) connected to a positive-electrode side of the high-voltage battery; a negative-electrode-side first resistor (Rb) connected to a negative-electrode side of the high-voltage battery; a positive-electrode-side second resistor (R3) having a first end grounded and a second end, a voltage of the second end being measured by the control unit; a negative-electrode-side second resistor (R4) having a first end grounded; a positive-electrode-side C contact switch (111) that is formed as a twin relay having relays (111a, 111b) operating in conjunction with each other and connected in parallel, and that is configured to alternatively switch a connection destination of a first end of the detection capacitor between a path including the positive-electrode-side first resistor and a path including the positive-electrode-side second resistor based on an instruction from the control unit; a negative-electrode-side C contact switch (112) that is formed  as a twin relay having relays (112a, 112b) operating in conjunction with each  other and connected in parallel, and that is configured to alternatively switch a connection destination of a second end of the detection capacitor between a path including the negative-electrode-side first resistor and a path including the negative-electrode-side second resistor based on an instruction from the control unit; and a path switching C contact switch (113) formed as a twin relay having relays configured to operate in conjunction with each other, one (113a) of the relays of the path switching C contact switch being configured to switch one of the relays of the positive-electrode-side C contact switch to the connection destination of the first end of the detection capacitor, and another one (113b) of the relays of the path switching C contact switch being configured to switch one of the relays of the negative-electrode-side C contact switch to a connection destination of the second end of the detection capacitor.']