FIRE SIGNALLING DEVICE Russian patent published in 1994 - IPC

FIELD: electric fire signalling. SUBSTANCE: sensor 1 are connected in parallel through matching unit 2 and are connected with central panel through three-wire line and optocoupler 4. When sensor 1 operates, each matching unit puts out current pulse of definite length which defines No. of sensor 1. If several sensor operate simultaneously, information is put out to line successively, which ensures against loss and distortion of information. Central panel is resistance-isolated from sensors 1, matching unit 2 and line. Moreover, identification of No. of operate sensor 1 on central panel is done by means of pulse selector 12 which enhances interference immunity of device, as short noises do not formation of signals at pulse selector output. Useful information, i.e. No. of sensor 1, is read by counter 15 in binary form and is recorded by register 16. On light indicator 20 Nos of operated sensor 1 are given in decimal form. Simultaneously with operation of light signalling, sound alarm is cut it. EFFECT: enhanced efficiency of operation, simplified design of fire signalling system. 4 dwg