Automatic circuit to switch on vehicle lights at dusk - uses photocell to release relay contacts connecting lights to battery

摘要

The automatic circuit switches on the side lights, headlights etc. of a motor vehicle when the background illumination drops below a given level e.g. dusk, tunnel etc. A photocell (1) monitors background illumination and when it drops below a given intensity the photocell voltage is no longer enough to hold a relay open. The contacts (3) of the latter close and connect the lights (5, 6) to the batery. An indicator lamp (4) is included on the dashboard. The circuit can be switched on and off by a second switch (7) once the ignition switch (8) is closed.