Patent ID: 9609718
Date: 2017-03-28
CPC Classifications: B60R,G01R,H02H,H02J,H02M,H05B,Y02B

Claim:
1. In-vehicle equipment comprising: an electronic device that operates using an in-vehicle battery as a power supply; a first power supply that has a step-down DC/DC converter to reduce a voltage of the battery; a controller that operates using the first power supply as a power supply to control the electronic device; a power supply reverse connection protector that has a FET connected between the battery and the electronic device, wherein the FET is connected such that a forward direction of a parasitic diode of the FET matches a direction in which a current flows at a time of normal connection at which the battery and the electronic device are connected with a positive polarity, and that at a time of reverse connection at which the battery and the electronic device are connected with a reverse polarity, the FET is turned off and the parasitic diode prevents a current flowing in a direction opposite to that at the time of the normal connection; and a second power supply that generates a drive voltage to turn on the FET of the power supply reverse connection protector at the time of the normal connection by using a voltage generated in the step-down DC/DC converter of the first power supply.