| 摘要 |
<p>This invention relates to a smoke detector of the type utilizing photo-electric detection of light reflected from smoke particles. The smoke detector includes a light source which is energized intermittently, and a photo-voltaic cell in the path of light of the light source which provides energy pulses in response to the light pulses reflected from smoke particles. A level detector detects the energy pulses and turns on an alarm actuator which actuates an alarm when smoke is detected. In accordance with the invention, the detector includes a voltage supply for driving the photo-voltaic cell, a capacitor connected across the voltage supply, and an isolating circuit between the capacitor and the voltage supply for isolating voltage pulses occurring at the power supply at least during the time that the light source is emitting light.</p> |
