JPH0459675B2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to storage type fire alarm equipment.

[Prior Art] In a fire alarm system in which one receiver and multiple fire detectors are connected by a pair of power and signal lines,
If a so-called accumulation function (a function that generates a fire signal when it is determined that a fire phenomenon exceeding the fire detection level continues to be detected by a fire detector for a predetermined period of time) is provided, temporary fire phenomena can be prevented. It is possible to prevent false alarms from occurring due to (fire-like phenomena). At this time, there are cases in which the fire detector side is provided with an accumulation function, and cases in which the receiver side is provided with an accumulation function.

When a fire detector is equipped with an accumulation function, if induced noise occurs in the power/signal line, the receiver may judge this induced noise as a fire signal, and in this case, a false alarm may occur. be. In this regard, it is advantageous to have a storage function on the receiver side, because if the receiver side has a storage function, it will not be determined that there is a fire due to one-off or short-term induced noise.

However, if the receiver side has a storage function,
Fire detectors are usually not equipped with an accumulation function, and even if a fire detector has an operation indicator light, the operation indicator light turns off when the fire phenomenon drops below the fire identification level. Therefore, when the fire phenomenon falls below the fire detection level after the accumulation operation has been completed for a predetermined period of time, the operation indicator light will automatically turn off, so there is a problem that it is not possible to visually confirm which fire detector has detected the fire. be.

[Object of the Invention] The present invention solves the problems of the prior art described above, and includes a receiver having an accumulation function that determines that there is a fire when a fire signal from a fire detector is continuously received for a predetermined period of time. In a storage type fire alarm system in which a fire detector is connected to the receiver and transmits a fire signal without self-holding while the fire detection unit detects a fire phenomenon exceeding the fire discrimination level, Even if the fire detector that sent out the fire signal no longer detects a fire phenomenon after the receiver's storage function determines that there is a fire, we will provide storage-type fire alarm equipment that allows you to visually check which fire detector detected the fire. The purpose is to provide

[Summary of the Invention] According to the present invention, when a fire sensor continuously detects a fire phenomenon, the fire signal side lowers the line-to-line voltage between a pair of power supply and signal lines to a voltage lower than that of the fire signal, This generates a control signal, and when the fire detector side detects a fire phenomenon and simultaneously detects a control signal from the fire receiver side, the self-holding circuit self-holds, and the self-holding circuit is connected in series to this self-holding circuit. This is to keep the operation indicator light connected to the light on.

[Embodiment of the Invention] FIG. 1 is a circuit diagram showing an embodiment of the present invention.

This embodiment includes a storage receiver RE, a fire detector DE, and power and signal lines l ₀ and l ₁ that connect the storage receiver RE and the fire detector DE.

The storage type receiver RE is a receiver that generates an alarm when a fire signal is continuously received from the fire detector DE for a predetermined period of time, and includes a fire signal detection circuit 10, a storage circuit 20, and an alarm circuit 30. , a control signal sending circuit 40, a power supply B that generates a voltage of about 24V, and a recovery switch SW.

The fire signal detection circuit 10 is a circuit that detects a fire signal from the fire detector DE.
Resistor 11 connected in series with DE and this resistor 1
1 and a transistor 12 that is turned on when a fire signal flows through the transistor 12.

The storage circuit 20 operates and produces an output when the fire signal detection circuit 10 continuously detects a fire signal for a predetermined period of time, and the storage circuit 20 operates to generate an output when the fire signal detection circuit 10 continuously detects a fire signal for a predetermined period of time.
This is a circuit that stops and restores operation when it no longer detects a fire signal, and is composed of an integrating circuit or a timer.

The alarm circuit 30 is a circuit that operates when the storage circuit 20 operates, and includes a transistor 31, a district relay 32 that operates a fire light, a district indicator light, an alarm bell, etc. (not shown), and a make contact of this district relay 32. It consists of 33.

The control signal sending circuit 40 is a circuit that sends out a control signal by lowering the voltage applied between the power supply and signal lines _l0 and _l1 when the alarm circuit 30 is activated, It has a make contact 41 of the district relay 32 and a Zener diode 42 of about 8V. The above control signals are connected to a pair of power and signal lines.
This is a signal that controls the fire detector DE via l ₀ and l ₁ . In other words, when the storage circuit 20 outputs, the control signal sending circuit 40 connects the pair of power supply/signal lines l ₀ ,
This is an example of a control signal sending circuit that generates a control signal by lowering the inter-line voltage of _l1 to a voltage lower than the fire signal, and sends this control signal to the fire detector DE.

On the other hand, the fire detector DE includes a fire detection section 50,
It has a constant voltage circuit 51, a fire signal sending circuit 60, an operation indicator LED, a voltage detection circuit 70 as a control signal receiving circuit, and a self-holding circuit 80.

The fire detection unit 50 detects fire phenomena, and includes sensor units (one or more) of thermal type, smoke type (ion, scattering, dimming, etc.), radiation type, gas type, etc.
and a detection section that determines whether the output of this sensor section has reached a predetermined level. That is, the fire detection unit 50 generates a detection output when it detects a fire phenomenon such as heat, smoke, flame light, or gas that exceeds a fire discrimination level.

The operation indicator LED lights up when the fire detection unit 50 is operating, and also lights up when the fire detection unit 50 is operating.
The RE storage circuit 20 lights up continuously after detecting a fire signal for a predetermined period of time.

The fire signal sending circuit 60 is a circuit that sends a fire signal to the storage type receiver RE when the fire detection section ₅₀ is operating. This circuit sends a fire signal to the fire receiver DE by changing the voltage across the fire detector to a first predetermined voltage (for example, 18V) that does not affect the normal operation of the fire detection section. In other words, the fire signal sending circuit 60
When operating, the power and signal lines l ₀ and l ₁ are connected to
A current is passed through the signal detection resistor 11 in the fire signal detection circuit 10 as a fire signal. That is, while the fire detection section 50 is generating a detection output, the fire signal transmission section 60 sends a pair of voltage signals as a fire signal within a voltage range in which the fire detection section 50 can normally perform a fire phenomenon detection operation. Power supply and signal line l ₀ ,
This is an example of a fire signal sending section that sends out a signal to _l1 . Also,
The fire signal sending circuit 60 includes a transistor 61;
Zener diodes 62 and 63 are included.

The voltage detection circuit 70 is a circuit that detects a voltage drop as a control signal by the control signal sending circuit 40 of the storage type receiver RE, and includes a transistor 71,
Zener diode 72 and resistors 73, 74, 75
a bridge circuit consisting of a comparator 76,
Transistors 78, 79 and voltage dividing resistors R1, R2
and has.

The self-holding circuit 80 is a circuit that self-maintains the operation of the fire detector when the above accumulation time has elapsed (that is, the voltage detection circuit 70 is activated) and a fire signal is generated. It is composed of thyristors 81 such as. This self-holding circuit 80
As a result of this operation, the operation indicator LED is kept lit.

Next, the operation of the above embodiment will be explained.

First, assume that the voltage of power supply B is 24V. If no fire phenomenon occurs, the fire detector
Only the small amount of current necessary for fire monitoring flows through the DE. Therefore, through the power and signal lines l ₀ and l ₁ ,
Between the input/output terminals _T0 and T1 of the fire detector DE,
Approximately 24V is applied.

Here, when the fire detection unit 50 detects a fire phenomenon exceeding the fire detection level, the transistor 61 is turned on, so the operation indicator LED lights up to indicate that the fire detection unit 50 is in the operating state, and the Zener Since the entire fire signal sending circuit 60 including the diodes 62 and 63 is conductive, current flows through the resistor 11 in the fire signal detection circuit 10. In this case, the fire detection unit 50 applies sufficient voltage (first predetermined voltage, for example 18V) to the input/output terminals T ₀ and T1 for fire monitoring (2V of the 18V is applied to the constant voltage circuit 51). , 16V is applied to the fire detection unit 50).

Then, as described above, when current flows through the resistor 11 of the storage receiver RE (that is, when a fire signal occurs), the transistor 12 turns on and the storage circuit 20 starts storing. When a fire signal is generated for a predetermined period of time, the storage circuit 20 is activated and the transistor 31 is turned on. As a result, the district relay 32 is operated, so that a fire light, a district indicator light, and an alarm bell (not shown) are operated. At the same time, the make contact 41 of the district relay 32 of the control signal sending circuit 40
is turned on, the voltage is increased to the voltage determined by the Zener diode 42 (second predetermined voltage, for example, 8V).
The voltage at the input and output terminals decreases, thereby sending out a control signal.

By the way, the fire detector DE is a fire detector 50.
If it is operating, the transistor 71 is on, so the Zener diode 72 and the resistor 73~
The bridge circuit consisting of 75 is energized, but
In the case of the first predetermined voltage, the comparator 7
6 does not output a High signal. However, in the above case, when the voltage between the input and output terminals T ₀ and T1 drops to the second predetermined voltage, which is the control signal, the voltage at the non-inverting input terminal of the comparator 77 is higher than the voltage at the inverting input terminal. Therefore, comparator 76
outputs a High signal. For this reason, the transistors 78 and 79 are turned on, and the gate voltage of the thyristor 81 is increased, so that the thyristor 81 is turned on and self-maintained, and the operation indicator LED maintains its lighting operation.

Therefore, the operation indicator LED is displayed when the fire detection section 50 is operating, and is also displayed after the storage type receiver has finished storage, so multiple fire detection signals can be connected to the same power supply and signal line. Even if the fire detector is connected, it is possible to reliably confirm which fire detector activated the fire detector. Furthermore, the operation indicator LED will not malfunction due to a temporary fire phenomenon. In other words, in the event of a temporary fire phenomenon, the storage type receiver will not operate and the input/output terminals will not operate.
Since the voltage between T ₀ and T1 does not reach the second predetermined voltage, the thyristor 81 does not turn on, so the operation indicator LED does not continue its display operation.

To reset the fire detector DE, it is sufficient to turn off the recovery switch SW. In this case, the current flowing through the thyristor 81 becomes less than the holding current, so the thyristor 81 is turned off.

In the above embodiment, the self-holding circuit 80 was explained as being a separate member from the voltage detection circuit 70, but the self-holding means is broadly considered, and the self-holding means includes the voltage detection circuit 70 and the self-holding circuit 81. It may be considered that it has.

In addition, when the receiver RE generates the second predetermined voltage, which is a control signal, a third signal line and a terminal for it are separately installed in order to send the second predetermined voltage to the fire detector DE. and fire detector DE
is provided with an AND means for detecting that a second predetermined voltage is generated in the third signal line and that the fire detection section is generating an output, and when this AND means is operated, the thyristor 81 is turned on. You may also do so.

FIG. 2 is a circuit diagram showing one embodiment of the storage circuit.

The storage circuit 20 includes a transistor 21 that turns on when a fire signal is detected, and a resistor 22 at this time.
It is constituted by an integrating circuit that accumulates charge according to the voltage across the terminal, and a Zener diode 26. The above integration circuit includes resistors 23a and 23
b, a capacitor 25, and a changeover switch 24, and by switching the changeover switch 24, different lengths of accumulation time can be obtained.

In other words, when a fire signal occurs, the transistor 21 is turned on and a predetermined voltage is generated across the resistor 22.
This voltage gradually charges the capacitor 25. This charging voltage is the Zener diode 26
When it becomes higher than , the alarm circuit 30 is activated. Further, the storage time of the storage circuit 20 is determined by the resistance value of the resistor 23a (or 23b) and the capacitance of the capacitor 25. Further, the diode 26a rapidly discharges the charge stored in the capacitor 25 when the fire signal is no longer received while the capacitor 25 is storing charge.

Instead of the storage circuit 20, a timer may be used which produces an output when the fire signal is continuously input for a predetermined period of time and is cleared when the input signal disappears within the predetermined period of time.

FIG. 3 is a diagram showing another embodiment of the storage circuit.

The storage circuit 20A is one that outputs a pulse signal as a fire signal when the fire detector DE detects a fire phenomenon of a predetermined level or higher (such a device may be a pulse-emitting type smoke detector, etc.) ) is used in the case of

The counter 27 counts each time it receives a fire signal from the fire signal detection circuit 10, and outputs an output when it counts 15, for example. The retrigger monostable multivibrator 28 is
It is operated by a fire signal, and its output time is longer than one period of the fire signal pulse and shorter than two periods thereof. For this reason, the monostable multivibrator 28 outputs while the fire signal pulse continues to be inputted from the fire detector DE without being interrupted.

The monostable multivibrator 29 is composed of a Schmitt trigger circuit or the like, and outputs an output at the down edge of the retrigger monostable multivibrator 28 to clear the coefficient operation of the counter 27.

Further, the control signal sending circuit 40 may send out a pulse signal or an FM/AM signal having a characteristic frequency as a control signal. In this case, the fire detector DE may be provided with a pulse signal or frequency signal detection circuit instead of the voltage detection circuit 70.

[Effects of the Invention] According to the present invention, while the fire detection unit detects a fire phenomenon that exceeds the fire discrimination level, the fire detector that transmits a fire signal without self-holding is connected to the fire receiver. , operates while receiving a fire signal from the fire detector, and when the operation continues for a predetermined period of time, it determines that there is a fire and outputs an output, and operates when no fire signal is received within the predetermined period of time. In storage type fire alarm equipment, the fire receiver has a storage circuit that stops and restores the fire.
A control signal sending circuit is provided that sends a control signal to the fire detector when the storage circuit operates for a predetermined period and produces an output, and the fire sensor includes a voltage detection circuit that detects the control signal and a voltage detection circuit. The fire receiver is equipped with a self-holding circuit that holds itself while the fire detector is generating a detection output at the same time as it detects the control signal, and an operation indicator connected in series with this self-holding circuit. , when the storage circuit continuously receives a fire signal for a predetermined period of time and determines that there is a fire, it sends out a control signal, and the fire detector that sends out the fire signal is controlled by the control signal, and its operation indicator light is displayed. is kept lit, and as a result, even if the fire phenomenon subsequently drops below the fire detection level, the operation indicator light of that fire detector continues to be lit. This has the effect of visually confirming which fire detector has detected a fire phenomenon that is determined to be a fire.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing one embodiment of the present invention. FIG. 2 is a circuit diagram showing one embodiment of the storage circuit. FIG. 3 is a block diagram showing another embodiment of the storage circuit. DE...Fire detector, RE...Storage type receiver, 1
0...Fire signal detection circuit, 20, 20A...Storage circuit, 30...Alarm circuit, 40...Control signal sending circuit, 50...Fire detection section, 60...Fire signal sending circuit, 70...Voltage detection Circuit, 80...Self-holding circuit.

Claims (1)

[Claims] 1. A fire detector and a fire receiver are connected by a pair of power and signal lines, and the fire detector detects heat, smoke, light of flame, gas, etc. exceeding a fire discrimination level. A fire detection section that generates a detection output when a fire phenomenon is detected, and a voltage within the voltage range in which the fire detection section can normally perform fire detection operation while this fire detection section is generating the above detection output. and a fire signal sending unit that sends a voltage signal as a fire signal to the pair of power/signal lines, and the fire receiver detects the fire signal sent to the pair of power/signal lines. a detection circuit, and when the fire signal detection circuit continuously detects the fire signal for a predetermined period of time, it operates and produces an output, and the fire signal detection circuit no longer detects the fire signal within the predetermined period of time; In a storage type fire alarm device having a storage circuit that sometimes stops and restores operation, and an alarm circuit that is activated by the output of this storage circuit, the fire receiver is configured to: The line-to-line voltage of the above pair of power and signal lines is
It has a control signal sending circuit that generates a control signal by lowering the voltage to a lower voltage than the fire signal and sends this control signal to the fire detector, and the fire sensor is connected to the pair of power sources and a voltage detection circuit that detects the control signal sent to the signal line; a self-holding circuit that holds itself when the fire detection section generates a detection output at the same time as the voltage detection circuit detects the control signal; An operation indicator light is connected in series to the self-holding circuit, and the series circuit of the self-holding circuit and the operation indicator light is connected between the pair of power and signal lines. Features storage type fire alarm equipment. 2. The storage type fire alarm equipment according to claim 1, wherein the storage circuit is capable of switching the predetermined time to a plurality of different times.