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Smoke detector

  • US 3,917,956 A
  • Filed: 03/08/1974
  • Issued: 11/04/1975
  • Est. Priority Date: 03/08/1974
  • Status: Expired due to Term
First Claim
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1. In a smoke detector of the type utilizing photo-electric detection of light reflected from smoke particles (in which) having a light source which is energized intermittently, first means including a photo-responsive device (is provided) and an amplifier to produce energy pulses in response to light pulses refected from smoke particles, and second means utilizing said energy pulses to control a signalling device, the improvement comprising a voltage supply for said first means, a capacitor connected across the voltage supply, and third means between the capacitor and the voltage supply for isolating the (amplifier) first means and the capacitor from voltage pulses occurring at the power supply at least during the time that the light source is emitting light.

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