| 摘要 |
Smoke fire signaling device relates to area of fire signalization and can be used in systems of fire signalization for reveal of increase of optical density of air by intensity of dispersion of infrared radiation. Smoke fire signaling device that has blocks for processing and control, former of signal of smoke registration, optical indicator, element of one-side conductivity, two input terminals for connection of circuit of fire signalization, current key, current and voltage restrictor, two capacitors, emitter, photo-receiver, optical chamber with light-absorbing walls, additionally includes voltage divider between output of block for processing and control and input of current key that is arranged on bipolar transistors connected by Darlington circuit, and division coefficient of of voltage divider in installed in such way that at thermo-stable amplitude of pulses at output of block for processing and control ratio of total temperature instability of voltage base-emitter of transistors of current key to voltage drop on emitter resistor of current key is equal by module to temperature coefficient of power of emitter. In the device proposed due to use between block for processing and control and inputs of current key of voltage divider with fixed division coefficient at which increase of current through emitter at increase of temperature due to increase of voltage drop on emitter resistor of current key at fixed value of voltage at input of current key decrease of power of emitter due to increase of temperature is compensated. |
