Automotive digital light control circuit with light bus monitor and windshield wiper light control circuit

Abstract

An apparatus for automatically turning out the headlights, and preferably also the tail/park lights, of a vehicle when the ignition switch is turned off, includes an auxiliary switch connected in electrical series between a vehicle light control switch and the vehicle headlights and tail/park lights so that both the light control switch and auxiliary switch must be closed to operate the headlights and tail/park light, and a bypass switch connected in electrical parallel with the auxiliary switch so that the bypass switch can be operated to bypass the auxiliary switch if the auxiliary switch is not working properly. The bypass switch is preferably also in electrical parallel with the vehicle light control switch so that the bypass switch can be used to bypass both the vehicle light control switch and auxiliary switch to operate the headlights and tail/park lights, for example, when the windshield wiper switch is on. Control circuitry linked to the vehicle ignition switch is provided to close the auxiliary switch when the ignition switch is on and the light control switch is closed to operate the headlights and tail/park lights but to open the auxiliary switch when the ignition switch is off. Bypass circuitry linked to the ignition switch is provided to monitor operation of the auxiliary switch and operate the bypass switch if the auxiliary switch does not function properly and/or also linked to the windshield wiper switch to close the bypass switch to operate the headlights and tail/park lights when the windshield wiper switch is closed. Both the control circuitry and the bypass circuitry turn off the headlights and tail/park lights when the ignition switch is turned off.

Dependencies are inferred from the claim text.