SMOKE FIRE ALARM Russian patent published in 2007 - IPC G08B17/107 G08B17/12 

FIELD: fire signaling, possible use in fire signaling systems to detect increase of optical density of air based on intensiveness of infrared radiation dissipation.

SUBSTANCE: in accordance to the invention, smoke fire alarm, which contains microcontroller 1, two transistor keys 2,11, one-sided conductivity element 3, two input clamps 4,6 for connecting fire alarm loop, light diode indicator 5, current and voltage limiter 7, resistor 8 and two capacitors 9,10, emitter 12, optical chamber 13 with light-absorbing walls, photo-receiver 14, additionally contains a serial RC-circuit 16,17, which connects circuits of emitters of first 2 and second 11 transistor keys. In suggested device due to usage of serial RC-circuit with its connection to other elements, creation of short light flashes is ensured in standby operation mode by light diode indicator 5, with extensive intervals between these flashes.

EFFECT: increased trustworthiness of alarm serviceability without increased current consumption of device as a whole.

1 dwg