| 摘要 |
A smoke fire detector relates to devices for smoke indication and embodied for use in fire alarm systems for detecting fire break with smoke.The inventive task is to develop smoke signaling device providing higher performance properties such as power consumption, sensitivity, stability, reliability, interference immunity and life time.The smoke fire detector comprises a set point integrating unit, a controlled pulsed oscillator, a smoke sensor, an amplifier, a controlled integrating device, a low-pass filter, a reset circuit, an alarm signal-conditioning box. An electric pulse generator is powered via a first-level comparator from the set point integrating unit connected to the power network via a stabilized current generator and the integrating device. A radiator and an optical radiation receiver and a light-diffusing space formed by their angular diagrams are positioned meeting the requirements of the axial symmetry or symmetry relative two planes crossing on the radiator-receiver axis. A detector smoke chamber is provided with a light-forming plate and sinusoidal peripheral guides for leading out straight-passing light beams and easing smoke approach. The sensor output via the amplifier, as well as the controlled pulse generator output are connected to the controlled integrating device. The latter is connected to the set point integrating unit input via the low-pass filter and the reset circuit. The set point integrating unit is connected to the input of the alarm signal-conditioning box via the integrator and the second level comparator. The performance ability of the detector is tested using an optical radiator calibrator (by pressing a knob on the housing), while the sensibility is checked by using a light-diffusing simulator.Fig.1 shows a complete circuit diagram, fig 2 gives timing sheets reflecting the optical smoke density in the detector chamber and pulses at stages corresponding to the standby state, procedure of smoke formation dynamics analysis and fire alarm procedure, fig 3 provides design features of the smoke fire detector manufactured according to the invention. |
