GB929667A - Improvements in and relating to anti-dazzle or light-subduing devices for vehicles - Google Patents

Abstract

929,667. Photo-electric control of anti-dazzle screens. G. L. BEBBINGTON. Nov. 22, 1961 Sept. 8, 1960], No. 30919/60. Class 40 (3). [Also in Group XXXII] An anti-dazzle or light-subduing screen in a vehicle is moved from an inoperative position to an operative position or vice versa, by an electric motor controlled by a circuit which includes a light-sensitive cell responsive to direct light rays such as from a light beam of an oncoming vehicle or sun rays. In the embodiment of the circuit shown, the output of a lightsensitive selenium cell S is fed to amplifier comprising six transistors TR1 ... TR6. Connected in the collector circuit of the transistor TR5 is a high-speed relay RL1 which is energized by the circuit when the cell S detects a light beam. A single contact S1 of the relay RL1 closes when the relay is energized and connects a further relay RL2 to a D.C. supply, the change-over contacts CT1, CT2 of which connect the supply to the armature of the motor M secured to the shaft of the anti-dazzle screen (Fig. 1, not shown). When the relay BL1 is deenergized the contacts S 1 , CT1 and CT2 are in the position shown and when it is energized the contacts move to the other position connecting the armature to the supply thus actuating the anti-dazzle screen until a limit switch LQ operated by a cam or the like is opened. When the relay RL1 is then de-energized the procedure is reversed and the motor rotates in the opposite direction until a further limit switch UQ is opened by a similar cam.