Relay welding detecting device

摘要

A relay welding detecting device detects welding of a relay (3) interposed between a motor driving circuit (6c) for driving an in-vehicle motor (4) and a battery (1). The relay welding detecting device includes a control determination unit that outputs a motor control signal to the motor driving circuit (6c) in a state where the relay (3) is controlled to be in an OFF state, and determines whether or not the welding of the relay (3) occurs based on a rotating position signal indicating a rotating position of the in-vehicle motor (4).