FIRE-ALARM SYSTEM Russian patent published in 1995 - IPC

FIELD: fire-alarm systems. SUBSTANCE: system has relay 1, detectors 2 which has like outputs to be connected together and with one output of winding of relay 1. Any other like output of detectors 2 is connected with output of adjusting resistor 3 through checking resistor 4. Voltage divider resistor 5 is connected through resistor 3 to control switch 7 at positive bus and with additional terminal of switch 7 at negative circuit through the second voltage divider resistor 6. EFFECT: improved reliability. 3 cl, 1 dwg