Surge control for electrical trailer brakes

摘要

The electrical brake coils of a trailer are energized when the stoplight switch of the towing vehicle is closed and the trailer surges forwardly with respect to the towing vehicle to cause the wiper of a rheostat to move relatively along the resistor of the rheostat. A hazard switch for causing the stoplights of the towing vehicle to flash is connected in parallel with the stoplight switch in the stoplight circuit of the towing vehicle. The resistor of the rheostat is formed with a normally non-conductive portion which prevents the brake coils from being repetitively pulsed with current when the hazard switch is actuated. Once surge braking has been initiated, however, the non-conductive portion of the resistor is rendered conductive so that current will be supplied continuously to the brake coils over the full range of movement which the trailer undertakes during surge braking.