Nohmi Bosai Ltd.

Nohmi Bosai Kabushiki Kaisha

Nohmi Bosai Co., Ltd.

Akio Tsumuji

Kaoru Takahashi

Ryuji Shutoku

Takashi Kobayashi

Akira Igarashi

Kouichi Hishino

A fire receiver enables a fire alarm system to be reliably set up while the work for installing the fire alarm system is simplified, even if an IC card storing necessary data cannot be prepared or even at a time when the operation of connecting all terminal devices to the fire receiver is not completed. When a connection of the IC card to a card reader is detected when power supply to the fire receiver is turned on, data stored in the IC card is fetched and the terminal devices are operated on the basis of the fetched data. When no connection of the IC card to the card reader is detected when the power supply is turned on, predetermined data is fetched from the terminal devices by polling the terminal devices, and the terminal devices are operated by the data fetched by polling.

Fire receiver in fire alarm system

Fire alarm system

A power supply control device is provided in a fire alarm system having terminals such as fire detectors and/or repeaters with comparators to detect abnormalities such as fire or an operating status of controlled apparatus, and is equipped with a reference voltage supply a source to supply reference voltage to the comparators, and a power supply control to allow the reference voltage to be supplied to the comparators only during the detecting time.

Power supply control device in fire alarm system

A line interruption supervisory device for a fire alarm system is capable of reliably carrying out the line supervision even if the line length is long and/or there is a large number of connected fire detectors. To this end, a terminating capacitor is connected across the terminal of a pair of power/signal lines to which fire detectors are connected. A memory first stores the voltage available on the power/signal lines when the line supervision is requested, immediately followed by the interruption by a cut-off circuit of the power supply to a pair of power/signal lines, and further followed by a comparison of the voltage available on the power/signal lines before the power supply interruption with a line voltage available after a lapse of a predetermined time from the power supply interruption by a line interruption discriminating circuit to determine, according to any difference between these voltages, whether there is an open power/signal line.

Line interruption supervisory device for a fire alarm system

A fire alarm system includes a receiver unit such as a fire control panel or a repeater having zone lines connected thereto, with various types of fire detectors being connected to the zone line. Supervising power is normally supplied to the zone lines. When the receiver unit receives a fire signal via a zone line from a fire detector, the receiver unit decides from what type of detector the fire signal was transmitted. Types of fire detectors include, for example, a type having as switching means only a mechanical contact for causing said zone line to be in a short-circuited condition, a type having as switching means a switching circuit with a self-holding function, or a type having a response lamp. In response to the receipt of the fire signal, either no power, or suitably reduced power or reduced constant current for the zone line to which the operated detector transmitting the fire signal is connected is supplied, depending on the type of detector that has operated, to thereby allow a reduction in power consumption.

Growing community of inventors

Tokyo, Japan

Akio Tsumuji