Patent ID: 7052093

Claim:
An electric parking brake system for applying braking force to a wheel of a vehicle, comprising: a motor; a parking brake that is driven by the motor to apply braking force to the wheel; a drive circuit that supplies electricity to the motor via an electricity supplying path to drive the motor; a current detection portion for detecting a current value supplied to the motor; a controller for controlling the drive circuit, wherein the controller causes the drive circuit to supply electricity to the motor such that a predetermined constant voltage is supplied to the motor, wherein, when the detected current value is equal to or greater than a predetermined permissible value, the controller causes the drive circuit to stop supplying electricity to the motor; at least two terminals located in the electricity supplying path and connected to the motor; a rotation detection portion that detects a rotation state of the motor; and a switching portion that is switched among a short-circuit state for short-circuiting the terminals, a closed circuit state for closing the electricity supplying path, and an open circuit state to open the electricity supplying path, wherein the switching portion is switched from the closed circuit state to the open circuit state when the supply of electricity to the motor is stopped, and the switching portion is switched from the open circuit state to the short-circuit state when the rotation detection portion detects that rotation of the motor is stopped after the supply of electricity to the motor is stopped.