SMOKE FIRE ALARM Russian patent published in 2009 - IPC G08B17/10 

FIELD: physics, alarm.

SUBSTANCE: invention is related to the field of fire alarm and may be used in systems of fire alarm for detection of increase of air optic density by intensity of infrared radiation scattering. Device comprises microcontroller (1), shaper (3) of smoke registration signal, current and voltage limiter (4), converter (2) voltage-current, the first (5) element of single-sided conductivity, condensers (7,8) and two input terminals (6,12), radiator (9), photo diode (11) and optic chamber (10) with light-absorbing walls, amplifier (13), high frequency filter (14), current mirror (15), commutator (16) and resistor (17). Due to application of amplifier (13), high frequency filter (14), current mirror (15), commutator (16) and resistor (17) with their links with other elements of circuit, matching of photo-EMF signals is achieved with analog input of microcontroller, both by level of signal and impedance of this chain.

EFFECT: simplification of manufacture, and lower consumption of power.

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