Photoelectric light switching appts. for burglary prevention - has back up circuit operated when main circuit fails, each circuit contg. respective photocell

摘要

The switching device turns on interior or exterior lights for a house when the occupants are absent. It uses two photocells respectively connected in a main switched circuit and a back-up circuit brought into operation upon failure of the main circuit, eg. due to a defective light bulb. The back-up circuit may control a discharge lamp. Pref. the two electronic circuits (3), the two photo cells (6,7), the discharge lamp (4), the supply pin (8) and the lamp socket (5) are all formed as an integral module, which fits into a normal lamp socket, its outer casing (1) being transparent or translucent for passage of the light provided by the discharge lamp (4).