CONNECTION DETECTING CIRCUIT

A circuit 10 includes a vehicle-side circuit 10A, a charger-side circuit 10B and a connecting part 10C. The vehicle-side circuit includes a power source 102, a first resistor 104 provided between the power source 102 and the connecting part 10C, a second resistor 106 which is connected to the first resistor 104 in series, a switch 108 which turns on or off current supply from the power source 102, a voltage detector 110 which detects a voltage at a connection point of the first resistor 104 and the second resistor 106, a determining part 112 which determines a state of connection between a vehicle-side connector 26 and a charger-side connector 36 and occurrence4 of a failure in the vehicle-side circuit 10A based at least in part on the voltage detected by the voltage detector 110 and an on/off state of the switch 108.