JPS6356590B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sound control circuit for a fire alarm system.

Conventional fire alarm systems consist of alarm wires wired to multiple warning areas, and multiple district relays that are activated by fire detection signals sent to the alarm wires.
and a fire relay that operates when any of the district relays is activated, and is configured to ring an alarm bell through the contacts of the fire relay. In such equipment, when performing functional tests of fire detectors and fire alarm systems, a switch for stopping the bell is connected in series with the bell circuit to avoid unnecessary confusion caused by ringing of the alarm bell. In some cases, the switch may be inserted to open the switch for maintenance and inspection. In this case, if you forget to close the switch again after maintenance and inspection, there is a serious drawback that the bell will not ring in the event of a fire. In order to eliminate this drawback, a bell stop relay that operates when the bell stop button is pressed is provided, and the normally closed contact of the relay is connected in series to the bell circuit, and a timer that operates after a certain period of time after the bell stop button is pressed is provided. A bell control circuit is known in which a make contact is connected in parallel to a normally closed contact of the bell stop relay. Even in this case, ringing of the bell is not guaranteed if a fire occurs within a certain period of time.

Furthermore, a flip-flop is provided which is set by pressing a bell stop button (non-lock), and the output of the flip-flop operates a bell stop relay, and subsequent operation of any district relay causes the relay to be activated. A control circuit is also known in which a reset signal is sent to a reset terminal of the flip-flop through a contact and a capacitor, thereby resetting the flip-flop and restoring the bell stop relay, thereby causing a bell to ring. However, in this case, it is not possible to stop the bell ringing in advance due to the test of the sensor, etc., and once the bell has rung, it can only be stopped by pressing the bell stop button. This may cause unnecessary confusion. Further, even if one sensor malfunctions, the bell immediately rings, which similarly causes unnecessary confusion.

The purpose of the present invention is to solve the above-mentioned conventional drawbacks and
It is possible to arbitrarily stop the sound of an alarm bell, etc. after the sound circuit rings, or to prevent the sound of an alarm bell, etc. from being generated in advance if necessary, and even when the sound is stopped, it is possible to prevent a serious fire from occurring. An object of the present invention is to provide a sound control circuit for a fire alarm system that can generate sound depending on the occurrence of fire alarm.

The sound control device of the present invention includes an alarm wire wired to each of a plurality of warning districts, a district circuit operated by a fire detection signal sent to the alarm wire, and a fire detection circuit operated by the output of any of the district circuits. a sound circuit that rings an alarm bell or the like in response to the output signal of the fire alarm circuit; and a sound stop circuit that connects a normally closed contact in series to the sound circuit and operates when a sound stop button is pressed. The fire alarm system is characterized by comprising means for restoring the sound stop circuit when two or more of the district circuits are activated.

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a circuit diagram showing a first embodiment of the present invention. That is, district relays RL ₁ to RL _o are connected between the alarm wires L ₁ to L _o wired in each warning area and the positive power supply +E, and fire detection signals are sent from the detectors connected to the alarm wires. (by grounding the alarm line or looping it with the common line C, etc.), the corresponding district relay will operate. Make contacts for each district relay
RL ₁ ~ RL _O are connected in parallel with the fire relay RF and connected in series between the positive and negative power supplies. In this embodiment, one district circuit is composed of a district relay RL ₁ , a contact rl ₁ and a normally closed contact rl' ₁ to be described later.
Therefore, when any district relay operates, the fire relay RF operates and closes its contacts RF.
Contact RF and the normally closed contact of the bell stop relay RB (described later)
A series connection circuit with rb sends power to the bell wire terminal B _p , causing the alarm bell to ring. The contact RF of the above fire relay RF constitutes a fire alarm circuit.

On the other hand, when the bell stop button is pressed, its contact
Set terminal S of flip-flop FF via rs
When a positive voltage is applied to FF, flip-flop FF is set, output terminal Q becomes high level, and bell stop relay RB operates. When the normally closed contact rb opens due to the operation of the bell stop relay RB, the bell circuit is cut off and the bell stops ringing. It is also possible to press the bell stop button in advance to open the contact point rd. The bell stop button is generally an acoustic stop button, and a bell stop relay RB and a normally closed contact rb constitute an acoustic stop circuit. The bell circuit may be an audio circuit such as a buzzer or a tape recorder.

Additionally, the normally closed contacts rl′ ₁ of the district relays RL ₁ to _{RL o}
.about.rl' _o and a resistor R are connected in series between the positive and negative power supplies, and Zener diodes Z ₁ to Z _o are connected in parallel to the contacts rl' ₁ to rl' _o , respectively. The connection point between the resistor R and the Zener diode _Z1 is connected to the + input of the comparator CA.
A constant reference voltage V _R is applied to one input of CA. The reference voltage can be easily obtained by dividing the power supply voltage using resistors R ₁ and R ₂ . The output of comparator CA is connected to the reset terminal R of flip-flop FF via capacitor _C1 . The Zener voltages of the Zener diodes Z ₁ and Z ₂ are smaller than the reference voltage _VR , and the sum of both Zener voltages is larger than the reference voltage _VR . However, for example, the Zener voltage of the Zener diode Z _o is greater than the reference voltage _VR . Now, assuming that the important fire detection signal is input to the alarm line L _o , when the district relay RL _o is activated by the fire detection signal input from the alarm line L _o , the zener is activated by the release of the contact rl′ _o . The Zener voltage of diode Z _o is applied to the + input of comparator CA, and the
CA is reversed. The inversion of the output signal of comparator CA is connected to the flip-flop via capacitor _C1 .
The signal is transmitted to the reset input R of the FF, and the flip-flop FF is reset. As a result, the bell stop relay RB is restored and the contact rb closes, causing the bell to ring. However, for example, when district relay RL ₁ operates and contact rl′ ₁ opens, the Zener diode
A Zener voltage is generated at _Z1 , but since the Zener voltage is lower than the reference voltage _VR , the comparator CA is not inverted. The same applies when district relay RL ₂ operates. Therefore, if you press the bell stop button in advance to set the flip-flop FF and then test the fire detectors connected to the alarm wires _L1 , _L2 , etc., the lamps not shown may turn on, etc. Therefore, although it is possible to confirm the operation, there is no need to cause confusion by ringing the bell. On the other hand, if a fire detection signal is sent from both alarm wires L ₁ and L ₂ due to the occurrence of a fire, both contacts rl′ ₁ and rl′ ₂ will open, so the Zener diode Z ₁
comparator by the sum of the Zener voltages of and _Z2
The alarm bell rings because CA flips and resets the flip-flop FF. Therefore, for example, if the alarm lines _L1 and _L2 are routed along the same route and the fire detectors are placed adjacent to each other, an alarm bell will ring when a fire occurs. In such a case, for example, even if one sensor detects cigarette smoke and generates a false fire signal, the alarm bell will not ring, but if both sensors detect an actual fire, the alarm bell will not ring. also has the effect of ringing an alarm bell. In other words, this has the effect of preventing false alarms from occurring. It would be more effective if different types of sensors were installed together instead of using the same type of sensors. Zener diode Z ₁ ~
Since the Zener voltage of Z _o can be set arbitrarily, it is possible to use different Zener voltages and weight each alarm line. For example, in important areas such as warehouses where there is little risk of false alarms, an alarm bell will ring immediately when one sensor is activated, and in other areas, when a detection signal is sent to two alarm wires. This can be said to cause a bell to ring. If the bell stop button is not pressed, the bell will of course ring immediately when a sensing signal from any alarm line is sent.

In this embodiment, by pressing the bell stop button, it is possible to stop the ringing bell or prevent the bell from ringing in advance.
In addition, even if the bell is stopped, the bell can be rung in the event of an important fire or detection signals from two or more alarm wires, so ringing the bell during tests, etc. will not cause unnecessary confusion. This also has the effect of preventing the alarm bell ringing for an actual fire from being lost due to forgetting to stop the bell. Furthermore, by considering the arrangement of sensors, etc., it is possible to prevent false alarms from occurring.

FIG. 2 is a block diagram showing a second embodiment of the invention. In other words, the sensing signal of each alarm line is
input to the computer CPU,
The CPU adds 1 to the fire count value stored in the built-in memory each time a sensing signal is input, and outputs a fire display signal to display the necessary fire, and
The device is configured to output a resounding pulse to reset the flip-flop FF when the fire count exceeds a certain number. Flip-flop FF closes contact rs by pressing the bell stop button.
When the bell is closed, the bell stop relay RB operates to open the contact rb to stop the ringing of the bell, and the bell rings again in response to a predetermined number of sensing signals, as described above. If you set the initialization routine program of the computer CPU to perform an initialization operation such as setting the fire count value stored in memory to "0" when the bell stop button is pressed, you can determine how many times the bell stop button is pressed. Even if you move,
Subsequent re-ringing of the bell can be done in the same manner. In addition, when weighting each alarm line, depending on the sensing signal input from the weighted alarm line, a weighting coefficient α may be added to the fire count value in the memory.
All you have to do is add . The count value for generating the resounding pulse and the weighting coefficients mentioned above can be arbitrarily set by the program, and can be easily changed, so it is highly flexible, and the hardware part can be simplified. . In this case, the "control means for generating a resounding pulse when the number of input signals reaches a predetermined number" is constituted by the computer CPU. The above control means can also be constructed, for example, by inputting and counting the sensing signal from the alarm line to a conventional counter, and applying an output pulse to the reset input of the flip-flop FF after a certain number of counts. Further, it is easy to reset and initialize the counter by pressing the bell stop button.

As described above, in the present invention, the sound stop circuit is operated by the output of the flip-flop, which is set by pressing the sound stop button and is reset when a certain number or more of the district circuits are activated.
Since the normally closed contact of the acoustic stop circuit is inserted in series with the acoustic circuit, the ringing of the acoustic circuit such as a fire alarm bell can be stopped in advance or at any time after ringing by pressing the acoustic stop button. It is possible to play the sound again under certain conditions even after the sound has stopped. Therefore, it is possible to prevent unnecessary noise from causing confusion during tests, etc., and
This has the effect of preventing bell ringing due to false detection or the like. In addition, even after pressing the sound stop button, the sound can be played again under certain conditions, so
Fire alarms will not be lost due to forgetting to stop and restore the system. Furthermore, it is possible to assign weights to each warning line, allowing for rational and appropriate fire supervision.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing a first embodiment of the present invention,
FIG. 2 is a block diagram showing a second embodiment of the invention. In the figure, L ₁ to L _o ... Alarm line, C... Common line, B _p ... Bell wire terminal, RL ₁ to RL _o ... District relay, RF... Fire relay, RB... Bell stop relay, FF...Flip-flop, CA...Comparator, R, _R1 , _R2 ...Resistor, rl ₁ ~ rl _o , rl' ₁ ~ rl' _o
... Contacts of district relay, Z ₁ ~ _{Z o} ... Zener diode, rf ... Contacts of fire relay, rb ... Normally closed contact of bell stop relay, rs ... Contact of bell stop button, C ₁ ... Capacitor , CPU...computer.

Claims (1)

[Scope of Claims] 1. Alarm wires wired to each of a plurality of warning areas, a district circuit activated by fire detection signals sent to the warning lines, and a fire alarm activated by the output of any of the district circuits. a sound circuit that rings an alarm bell or the like based on the output signal of the fire alarm circuit; and a sound stop circuit that connects a normally closed contact in series to the sound circuit and operates when a sound stop button is pressed. A bell control circuit for a fire alarm device, characterized in that the fire alarm device includes means for restoring the sound stop circuit when two or more of the district circuits are activated. 2. In the acoustic control circuit for a fire alarm device according to claim 1, a Zener diode is connected in parallel to the normally closed contact of each district circuit, and the normally closed contact of the district circuit and the Zener diode are connected in parallel. A comparator that applies a voltage to a series connection circuit in which a plurality of connection circuits are connected in series through a resistor and compares the voltage across the series connection circuit with a reference voltage; The device is characterized in that it comprises a flip-flop that is reset by an output signal from a comparator, and the acoustic stop circuit is operated by the output of the flip-flop. 3. The sound control circuit for a fire alarm device according to claim 1, comprising a control means for generating a resounding pulse when the number of input signals reaches a predetermined number,
The sound stop circuit is characterized in that the sound stop circuit is restored by a resound pulse outputted by the control means. 4. The sound control circuit for a fire alarm device according to claim 3, wherein the control means is constituted by a counter. 5. The sound control circuit for a fire alarm device according to claim 3 or 4, wherein the control means is initialized by pressing the sound stop button.