Patent ID: 8981265
Filing Date: 2015-03-17
Classification: B64C,B64D,H02H,H05B

Abstract:
1. An aircraft comprising a windshield having a heatable member for removing snow, fog and/or ice from an outer surface of the windshield, the heatable member comprising a pair of spaced bus bars and an electrically conductive member between and in electrical contact with the spaced bus bars, the bus bars connected to an electrical power source to flow current through one of the bus bars, through the electrically conductive member and through the other bus bar to heat the electrically conductive member to heat the outer surface of the windshield, and an electrical system to monitor and/or control performance of the heatable member, the electrical system comprising: a temperature sensor for sensing the temperature of the heatable member; a first switch electrically connecting the power source to one of the bus bars of the heatable member, wherein the first switch in a closed position provides a continuous electrical path from the power source through the first switch to the heatable member, and the first switch in an open position electrically separates the power source from the heatable member to deactivate the heatable member; an arc monitoring and detection system for monitoring voltage of the electrical system at a position between the power source and the heatable member; a heat controller electrically connected to the temperature sensor and acting on the first switch to open the first switch when the temperature of the temperature sensor exceeds a predetermined temperature; a second switch electrically connecting the temperature sensor to the heat controller, wherein the second switch in a closed position electrically interconnects the temperature sensor and the heat controller, and in an open position disconnects the heat controller and the temperature sensor, wherein the second switch is moved from the closed position to the open position by a signal from the arc monitoring and detection system indicating that the voltage and/or current measured by the arc monitoring and detection system exceeds a predetermined level; wherein with the first switch and the second switch in the closed position a first electric path is provided from the power supply through the first switch, through the heatable member to the power source, and a second electrically conductive path is provided from the temperature sensor, through the second switch, to the heat controller, wherein the heat controller opens the first switch when the temperature of the heatable member measured by the temperature sensor equals and/or exceeds a predetermined temperature, and wherein the arc sensor sends a signal to open the second switch when the voltage and/or current measured by the arc sensor exceeds a predetermined level and the heat controller responsive to the opening of the second switch opens the first switch.