Patent ID: 6911796

Claim:
An aircraft wiping system for an aircraft comprising: an aircraft windscreen; an aircraft main DC power supply; a DC windscreen wiper motor which is actuated to move a windscreen wiper across the aircraft windscreen, the wiper motor being connected to the aircraft power supply so that a high voltage side and a low voltage side of the wiper motor are present; and a power control device which is connected at the low voltage side of the wiper motor, for controlling the electrical power available to the wiper motor from the main power supply, the power control device including a) a pulse width modulating device connected to the low voltage side of the wiper motor, the pulse width modulating device operating by power derived from the main cower supply, and b) a current switch located at the low voltage side of the wiper motor for switching current on and off to the wiper motor under the control of the pulse width modulating device, the current switch thus controlling the power to the wiper motor.