Fire alarm system and booster

Patent metadata

Field	Value
Publication number	US-11501631-B2
Application number	US-202117330708-A
Country	US
Kind code	B2
Filing date	May 26, 2021
Priority date	Jan 21, 2019
Publication date	Nov 15, 2022
Grant date	Nov 15, 2022

Abstract

A fire detector is connected to a loop transmission line connected to a receiver. When the loop transmission line is normal, a transmission unit is connected to the fire detector. When a disconnection failure occurs, a disconnection monitoring unit turns on switching circuits to connect the end of the loop transmission line to the transmission unit, and the receiver connects to the fire detector from both ends of the loop transmission line. An input/output switching booster is inserted and connected in the middle of the loop transmission line, and when the start side transmission line is disconnected and the switching circuits are turned on, the input/output is switched. Accordingly, the input/output switching booster amplifies the down signal input from the terminal side transmission line and outputs it to the start side transmission line and at the same time amplifies the up signal input from the start side transmission line.

First claim

The invention claimed is:

1. A booster inserted in the middle of a loop transmission line connected in a loop, comprising:
a down signal boost circuit that amplifies an input down signal in one direction and outputs;
an up signal boost circuit that amplifies an input up signal in one direction and outputs;
a switching circuit having a first switching position and a second switching position,
upon the first switching position, a start side transmission line is connected to the input of the down signal boost circuit, and at the same time, the output of the down signal boost circuit is connected to a terminal side transmission line, and the input of the up signal boost circuit is connected to the terminal side transmission line, and at the same time, the output of the up signal boost circuit is connected to the start side transmission line,
upon the second switching position, the input of the down signal boost circuit is connected to the terminal side transmission line, and at the same time, the output of the down signal boost circuit is connected to the start side transmission line, and the input of the up signal boost circuit is connected to the start side transmission line, and at the same time, the output of the up signal boost circuit is connected to the terminal side transmission line;
a first voltage detector that detects the line voltage of the start side transmission line;
a second voltage detector that detects the line voltage of the terminal side transmission line; and
a booster control unit for controlling the input/output switching circuit,
upon a predetermined line voltage being detected by the first voltage detector and the second voltage detector, the input/output switching circuit is switched to the first switching position, and
upon the predetermined line voltage is not detected by the first voltage detector and at the same time, the predetermined line voltage is detected by the second voltage detector, the input/output switching circuit is switched to the second switching position.

2. The booster according to claim 1 ,
wherein the loop transmission line is connected in a loop to a receiver or a repeater connected to a receiver of a fire alarm system, and connects a fire detector.

3. The booster according to claim 1 ,
wherein the down signal is a voltage signal that changes the line voltage, and the up signal is a current signal that changes the line current.

4. The booster according to claim 1 ,
wherein the booster has a unique address.

5. The booster according to claim 1 ,
wherein the booster includes an indicator light indicating a signal amplification direction.

6. The booster according to claim 1 ,
wherein a plurality of the boosters are inserted and connected to the loop transmission line.

7. A booster inserted in the middle of a loop transmission line connected in a loop, comprising:
a first down signal boost circuit that amplifies an input down signal in one direction and outputs;
a second down signal boost circuit that amplifies an input down signal in the opposite direction and outputs;
a first up signal boost circuit that amplifies the input ups signal in one direction and outputs;
a second up signal boost circuit that amplifies the input up signal in the opposite direction and outputs;
an input/output switching circuit having a first switching position and a second switching position,
upon the first switching position, the input of the down signal boost circuit is connected to a start side transmission line, and at the same time, the output of the first down signal boost circuit is connected to a terminal side transmission line, and
the input of the first up signal boost circuit is connected to the terminal side transmission line, and at the same time, the output of the first up signal boost circuit is connected to the start side transmission line,
upon the second switching position, the input of the second down signal boost circuit is connected to the terminal side transmission line, and at the same time, the output of the second down signal boost circuit is connected to the start side transmission line, and the input of the second up signal boost circuit is connected to the start side transmission line, and at the same time, the output of the second up signal boost circuit is switched to the second switching position for connecting to the terminal side transmission line;
a first voltage detector that detects the line voltage of the start side transmission line;
a second voltage detector that detects the line voltage of the terminal side transmission line; and
a booster control unit for controlling the input/output switching circuit,
upon a predetermined line voltage is detected by the first voltage detector and the second voltage detector, the input/output switching circuit is switched to the first switching position, and
upon the predetermined line voltage is not detected by the first voltage detector, and at the same time, the predetermined voltage is detected by the second voltage detector, the input/output switching circuit is switched to the second switching position and held.

8. The booster according to claim 7 ,
wherein the loop transmission line is connected in a loop to a receiver or a repeater connected to a receiver of a fire alarm system, and connects a fire detector.

9. The booster according to claim 7 ,
wherein the down signal is a voltage signal that changes the line voltage, and the up signal is a current signal that changes the line current.

10. The booster according to claim 7 ,
wherein the booster has a unique address.

11. The booster according to claim 7 ,
wherein the booster includes an indicator light indicating a signal amplification direction.

12. The booster according to claim 7 ,
wherein a plurality of the boosters are inserted and connected to the loop transmission line.

Assignees

• Hochki Corp
• Hochiki Co

Inventors

• Matsuda Yoshihiro
• Kaneko Shigeru
• Ono Takehiro
• Ishida Akira

Classifications

• G08B25/14

  Central alarm receiver or annunciator arrangements · CPC title

• G08B25/003

  Address allocation methods and details · CPC title

• H04B1/44

  Transmit/receive switching · CPC title

• G08B29/06

  Monitoring of the line circuits, e.g. signalling of line faults · CPC title

• G08B25/045

  with sensing devices and central station in a closed loop, e.g. McCullough loop · CPC title