Multifunction aircraft windscreen wiper control system

摘要

A wiper control system which includes dual wiper control circuits operating from a single rotary control switch, which is mounted in a cockpit of an aircraft remote from the rest of the wipers and system components which are mounted near an aircraft windscreen in a housing from which a motor converter drive shaft protrudes generally normal to a portion of the airframe surface. The drive shaft is connected to one end of a wiper arm and the second end of the wiper arm is rotatably attached to the wiper blade. The dual wiper control circuits are electrically isolated from each other. The rotary switch includes dual voltage dividers and a single axial rotating member to create an analog voltage output signal representative of the control switch position which is interpreted by a controller circuit. The rotary switch speed selections include a HIGH speed, a LOW speed, an INTERMITTENT delay selection, and also a selection for PARK and OFF. The control circuit provides a digital signal input to a logic circuit which determines the rotary switch position and produces a digital output signal to an amplifier circuit that drives the windscreen wiper motor, which in turn drives the wiper arm at the selected speed. A function decoder and commutation logic device prevents motor overheating and power amplifier overheating.