JPS6134693A - Fire alarm - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION "Field of Industrial Application" The present invention relates to a fire alarm system, and more particularly to a fire alarm system that can identify the type of fire detector activated in a fire receiver.

``Prior Art'' Conventionally, a fire alarm system generally consists of a fire receiver, a pair of lines extending from the receiver to a warning area, and a plurality of fire detectors connected in parallel between the pair of lines. ing. In order to identify which fire detector has activated at the receiver, each detector is equipped with an oscillator with its own frequency, and when activated, this oscillator is interlocked and this signal is superimposed on the line. Distinguish the frequency of this signal,
There is a method to identify activated sensors. (For example, Japanese Utility Model Publication No. 54-41669) Also, by connecting a constant voltage element in series to a highly sensitive fire detector, and directly connecting a low-sensitivity fire detector, it is possible to There is a method on the receiver side to identify the type of sensor that was activated based on the difference in voltage between the lines.

(For example, Japanese Utility Model Application No. 57-175288) When linking a fire alarm system with a smoke prevention system or a fire extinguishing system, it is generally done based on the operation of a low-sensitivity fire detector due to reliability issues. . Therefore, when high-sensitivity and low-sensitivity detectors are connected to the same line, it is necessary to identify whether the low-sensitivity fire detector is activated.

``Problems to be Solved by the Invention'' In conventional fire alarm systems, in which each fire detector is provided with an oscillator for identification, the circuit configurations on both the detector and receiver sides become complicated. The method of identifying fire detectors based on the difference in line voltage when they are activated is affected by line resistance when the line is long, making identification difficult, especially when there are many types of fire detectors to be identified. Reliability becomes an issue.

This invention provides a switch circuit for recovering with recovery signals having different time widths depending on the type (sensitivity, type) of the fire detector, and the receiver includes a recovery signal generating means; By providing a recovery confirmation means, it is possible to identify the type of fire detector that has activated.

1. Even if there are relatively many types of fire detectors, fire detectors that operate reliably can be identified without being affected by line resistance.

Embodiment An embodiment of the fire alarm device of the present invention will be described with reference to the block circuit diagram shown in FIG. 1 and the timing chart shown in FIG. 2.

In FIG. 1, the fire alarm system of the present invention is comprised of the following. The fire receiver R/C includes a power source E, a wire-wound resistor R4 such as a relay that detects the operation of the fire detector DE,
A recovery pulse generator 3 that can generate pulses with sequentially different pulse widths, and a pair of lines based on the recovery pulses.
Transistor Q3 short-circuiting between C and a pair of lines, C
Fire detector DB activated from the voltage between and the restoration signal
and a recovery confirmation unit 4 that identifies the recovery and type of recovery. The fire detector DE is composed of a sensor section 1 that detects phenomena such as heat, smoke, flame, etc. when a fire occurs, and a switch circuit 2 that enters a conductive state in response to a detection signal from the sensor section 1. The switch circuit 2 includes resistors R7 to R3, a capacitor C0,2, a PNP type transistor Q, and an NP
It is composed of an N-type transistor Q2.

There is a fire detector like this between the train, a pair of tracks, and C.
Multiple E's are connected.

The operation of the fire alarm system of the present invention configured as described above will be explained based on the timing chart of FIG.
A pair of tracks during normal monitoring.

The voltage VCL across C is maintained at a predetermined value (generally 24V). When the sensor section 1 of the fire detector DE detects a fire phenomenon, a trigger signal is applied to the base of the transistor Q2 of the switch circuit 2. Transistor Q2 becomes conductive and transistor Q also becomes conductive and maintains this state. Therefore, time T. A pair of railroad tracks, C
During this time, a certain level of voltage remains and a larger current flows than during monitoring. The fire receiver detects this current using a relay or the like and indicates the occurrence of a fire on an alarm display (not shown).

The switch circuit 2 remains on for a period of time determined from the time constants of the resistor R1, capacitor C1, resistor R2, and capacitor C2, and then the continuity state is released and restored by reducing the voltage of C to a predetermined value or lower (lower than the holding current). do. Differences in the sensitivity of sensor part 1 (classified into types 1 to 3 according to the Fire Service Act). Further, the recovery time of the switch circuit 2 is made different depending on the sensor (ion sensor or photoelectric smoke sensor, temperature sensor using a bimetal, thermistor, etc.).

The recovery confirmation section 4 of the fire receiver outputs a signal to the recovery pulse generation section 3 after confirming the operating state of the fire detector DE.

The recovery pulse generator 3 has a pulse width TA (for example, 7.5 m).
A pulse of 5eC) is generated to turn on transistor Q. A pair of tracks, the difficulty between C ■cL is time 'r,
, it becomes almost zero during T2. Then, at time T3, which is several milliseconds after time T2, the restoration confirmation unit 4 determines the state of the fire detector DE from the voltage VCL.

If it has been restored, the type of fire detector DE that was operating is identified, and this identification signal is output to a signal processing circuit (not shown). If the recovery has not been completed, the recovery pulse generator 3
Outputs a signal to. The recovery pulse generator 3 generates a pulse with the next longest pulse width TB (for example, 17.5 m5eC). The voltage ■cL is almost zero during the time T4+T5. Then, at time T6 again, the recovery confirmation unit 4 judges the state of the fire detector DE, and if it has recovered, it outputs an identification signal for the type of fire detector DE, and if it has not recovered, it sends a signal to the recovery pulse generator 3. Output. The recovery pulse generator 3 generates the next longest pulse width Tc (for example, 27.5 m sec
) outputs a recovery signal. Then, the recovery confirmation unit 4 performs the same operation.

In this way, the recovery signals with short pulse widths are sequentially output, and the type of fire detector DE is identified from the recovery state. Even if a plurality of devices DE are operating, they can be identified at the same time.

Generally, even if the fire detector DB is restored, it will operate again when the sensor unit 1 detects a fire phenomenon.

It usually takes some time for the computer to restart after recovery. Therefore, it is only necessary to check whether or not the system has been restored between the end of the restoration signal and the re-operation.

For example, the fire detector DE that is restored with a pulse width TA is set as a high-sensitivity smoke detector, the fire detector DE that is restored with a pulse width TB is set as a low-sensitivity smoke detector, and the pulse width T. If the fire detector DB that is restored is set to a low-sensitivity heat detector, the alarm device will be activated if a high-sensitivity smoke detector is activated, and the alarm device will be activated if a low-sensitivity smoke detector is activated. The operation is linked with the smoke prevention device. Furthermore, a low-sensitivity heat sensor can be used to configure a disaster prevention system that links the operation of an alarm system and a fire extinguishing system.

``Effects of the Invention'' As explained above, the fire alarm system of the present invention does not require a complicated circuit especially in the fire detector DE, and there is no influence of the resistance of the line C, and the fire alarm system is capable of detecting a fire. Since it is possible to identify the type of fire detector DE activated by a fire alarm, it is possible to provide a highly reliable fire alarm system suitable for interlocking with smoke prevention equipment and fire extinguishing equipment.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram showing an embodiment of the fire alarm system of the present invention, and FIG. 2 is a timing chart for explaining the operation of FIG. 1...Sensor part, 2...Switch circuit, 3...
Restoration pulse generation section, 4... Restoration confirmation section, DE... Fire detector, RC, , Fire receiver, E... Power supply, R4
~4...Resistance, CI + 2...Condenser v, Q,
~3...Transistor, L. C...railway.

Claims (1)

[Claims] A fire receiver, a pair of lines extending from the fire receiver to a warning area, and a device connected between the pair of lines, maintaining continuity between the pair of lines at low impedance when a fire is detected, and reducing the current in the lines. In a fire alarm system consisting of a plurality of fire detectors that recover by a recovery signal that lowers the current to below the holding current, the fire detector includes a sensor section that detects a fire phenomenon, and a sensor section that maintains continuity by the output signal of the sensor section. and a switch circuit that recovers with a recovery signal at different times depending on the type of the sensor section, and the receiver includes a recovery signal generating means that can sequentially generate the recovery signal at different times. A fire alarm device comprising: recovery confirmation means for confirming the recovery state after outputting the recovery signal and before reactivating the fire detector, and identifying the type of the activated fire detector. .