Patent ID: 8180526

Claim:
Equipment for vehicle comprising: a vehicle-mounted unit which runs with respect to a vehicle body ground to which a negative electrode of a battery power source is connected, for transmitting and receiving a communication signal in a digital form; an impedance component having an end which is connected to said vehicle body ground, and another end which is connected to a circuit ground; a circuit to be controlled which runs with respect to said circuit ground; a control unit which runs with respect to said circuit ground, for controlling said circuit to be controlled, and for outputting a communication signal in a digital form which is to be transmitted to said vehicle-mounted unit; a communication interface circuit which runs with respect to both said vehicle body ground and said circuit ground, for cancelling a potential difference which occurs between said vehicle body ground and said circuit ground due to a flow of a current which flows through said circuit to be controlled into said impedance component, and for carrying out bidirectional communications of said communication signal between said vehicle-mounted unit and said control unit.