Hochiki Corporation

C. Hochiki Corporation

Hiroyuki Kitta

Yukio Yamauchi

Hiroshi Sawa

Shinichi Aizawa

A fire detector comprising a socket and a detector head with an electric circuit therein. The socket is provided with couplings for voluntarily defining the structure of an engaging portion thereof to designate a detector head to be coupled and each engaging portion of the detector heads have a specific structure to engage with the engaging portion defined by the couplings. Hence, no detector head other than the designated detector head can be coupled to the socket plate.

Detector coupling mechanism

In response to oscillator output pulses, a sample pulse generator supplies sample pulses to a fire sensor. In response to the sample pulses, the fire sensor produces a fire sensor signal. A judging circuit receives the fire sensor signals and, if they exceed a predetermined level, produces a judging pulse having a longer pulse duration than the oscillator pulses. This judging pulse is used to trigger an alarm signal. A monitor circuit consists of an AND gate and an OR gate. The AND gate receives as inputs the oscillator pulses and the judging pulses. The OR gate receives as inputs the output of the AND gate and the sample pulses. The output of the OR gate constitutes a monitor pulse that allows the simultaneous monitoring of three conditions, as follows:

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Yamato, Japan

Hiroyuki Kitta