FIRE HEAT DETECTOR Russian patent published in 2009 - IPC G08B17/00 

FIELD: physics; alarms.

SUBSTANCE: present invention pertains to fire alarms and can be used in fire alarm systems for detecting increase of ambient temperature above a set threshold value. The technical outcome is high noise immunity of the detector as a whole. This outcome is achieved by that, the fire heat detector has a heat sensor, LED indicator, two transistors and two diodes, three capacitors, seven resistors and two input terminals. The detector also has a current pulse generator on two transistors, a capacitor and four resistors. Due to use of an insignificant number of elements with the given connections, all requirements for specification documents of fire heat detectors are met. The detector also retains its state after effect of reverse voltage pulses, which are generated by control and indicating devices with alternating supply of the fire alarm loop circuit. In the stand-by mode of operation, the LED indicator generates short light pulses with time duration between these flashes. This allows for determining operating capacity of the fire heat detector and presence of supply voltage on the connected fire alarm loop circuit.

EFFECT: high noise immunity of the detector.

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