Automatic control for dipping headlights - having time delay circuit operating with light intensity monitoring photocell

摘要

A photocell is positioned at the front of the vehicle to monitor the light intensity of approaching vehicles. When that intensity exceeds a set level then the headlamps are dipped. A time delay circuit, comprising RC elements delays the dripping operation for two to six seconds so that once the lights are dipped they cannot be restored to full beam immediately, which could happen if the approaching vehicle dips its lights and reduces the intensity on the photocell suddenly. The output of the time delay circuit is fed to an amplifier to operate the switching relay.