Fire detector
First Claim
Patent Images
1. A fire detector which comprises:
- a fire detecting means adapted to be actuated upon receiving a call by polling from a central signal station and to produce an output signifying a change in physical phenomena caused by fire, in the form of an analog voltage;
a voltage-pulse width converting means connected to the fire detecting means for converting the analog output voltage therefrom into a pulse of a width corresponding thereto;
means for generating clock pulses of high frequencies;
a pulse counter connected to the clock pulse and to the pulse width converting means for counting the clock pulses occurring during the duration of the pulse produced by said voltage-pulse width converting means;
means connected to the clock pulse generator for transmitting the count produced thereby to the central station in digital form
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Abstract
A fire detector which outputs a change in physical phenomena caused by fire, such as a change in smoke density, in the form of analog voltage signal, by, for example, a photoelectric type sensor, an ionization type sensor, a thermal sensor, a gas sensor or the like, converts the output voltage into a pulse width corresponding to the voltage level by a voltage-pulse width converting circuit, counts quick clock pulses over the pulse width by a pulse counter, and transmits the count output from the pulse counter, in the form of digital signal, to a central signal station.
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4 Claims
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1. A fire detector which comprises:
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a fire detecting means adapted to be actuated upon receiving a call by polling from a central signal station and to produce an output signifying a change in physical phenomena caused by fire, in the form of an analog voltage; a voltage-pulse width converting means connected to the fire detecting means for converting the analog output voltage therefrom into a pulse of a width corresponding thereto; means for generating clock pulses of high frequencies; a pulse counter connected to the clock pulse and to the pulse width converting means for counting the clock pulses occurring during the duration of the pulse produced by said voltage-pulse width converting means; means connected to the clock pulse generator for transmitting the count produced thereby to the central station in digital form - View Dependent Claims (2, 3, 4)
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Specification