SMOKE DETECTOR Russian patent published in 2007 - IPC G08B17/107 

FIELD: fire-alarm system.

SUBSTANCE: smoke detector can be used for revealing increase in optical air density on base of intensity of dissipation of light IR-radiation. Smoke detector has one-sided conducting element. Input of the element is connected with first terminal which connects it with fire-alarm signaling system and output - with first output of smoke registration signal former electric supply and with input of current-limiting element. Output of current-limiting element is connected with first output of capacitor, which second output connected with common bus, with second terminal for connecting with alarm signaling system stub and with second output of electric power of smoke registration electric power former. Output of the latter is connected with indicator and output is connected with output of binary counter, with C-input of the counter and with first input of clock-pulse oscillator. First output of the latter is connected to V-input of binary counter and with first input of comparison circuit. Output of comparison circuit is connected with R-input of binary counter. Second input of comparison circuit is connected with output of amplifier and third input is connected with output of power voltage rejection circuit. Inputs of amplifier are connected with photodiode. Photodiode optically communicates with IR irradiator through chamber having light-absorbing walls. IR radiator is connected with output of current switch. First power output of switch is connected with first output of capacitor and with input of integrator which has output connected with first power output of amplifier. Second power output of amplifier is connected with second power output of current switch and with common bus. Smoke detector has additional high frequency filter which output has connected with input of current switch and input - with second output of clock-pulse oscillator. Second input of clock-pulse oscillator is connected with output of power voltage rejection circuit. Power outputs of the circuit are connected with corresponding power outputs of amplifier, clock-pulse oscillator, binary counter and comparison circuit. Due to introduction of circuit for controlling clock-pulse oscillator by power voltage rejection circuit, galvanic separation of input circuit of current switch by high-frequency filter and separation of power circuits of current switch from other elements of circuit by integrator it is possible to exclude effect of blocking of voltage drop at logic elements at value being less than minimal value of working voltage of these logic elements, and to provide stable starting of integrator as well as improvement of its operation.

EFFECT: improved efficiency; higher reliability of operation.

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