Fire detector

Abstract

To provide a fire detector, even with a communication function, that can be installed in a pulse-flow type fire receiver, which is made not to be determined as a communication error failure.SOLUTION: A smoke or heat detector with a communication function that is connected to a district circuit line 2 from which a fire receiver 1 extends includes a pulse flow detection circuit 36 that detects a pulse flow and a communication circuit 35 that communicates with the fire receiver to exchange information, and deactivates the communication function of the communication circuit when the pulse flow detection circuit detects that a pulse flow is being applied to the district circuit line.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a fire alarm system, as well as a fire receiver and a sensor used in the fire alarm system.

Background Art

[0002] Fire receivers of fire alarms are of two types: pulsating current type and direct current type. The fire receiver extends an area circuit line for connecting sensors outside, and connects one or more sensors to the area circuit line. For a pulsating current type fire receiver, a pulsating current is applied to the area circuit line, and for a direct current type fire receiver, a direct current is applied to the area circuit line. In the direct current type, the fire receiver and the sensor have a communication function, and each transmits and receives various information, which may be used as information necessary for fire processing. There was a time in the past when the pulsating current type was mainstream, but recently the direct current type has become mainstream. In the case of the direct current type, there are models in which the fire receiver and the sensor communicate with each other to exchange information, and more accurate fire alarms are made possible by the exchange of information, which has been popularized in recent years. However, there are still pulsating current type fire receivers that exist and continue to operate. Therefore, suppliers need to provide sensors compatible with pulsating current as required for maintenance. For this reason, suppliers need to prepare both sensors for pulsating current and sensors for direct current, and the types of sensors have increased.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As shown in Patent Document 1, there is a detector with a communication function that can communicate with a fire alarm receiver. In this case, the fire alarm receiver applies DC to the district circuit line. When a detector with a communication function is connected to a pulsating current type fire alarm receiver, the communication function may be disrupted by the voltage fluctuations (full-wave or half-wave waveform) of the pulsating current, which can lead to an increase in the detector's current consumption or cause the detector to detect a communication error and be unable to operate normally.

[0005] Therefore, the present invention has been made in view of these points, and aims to enable the installation of a communication-enabled detector in a pulsating-current type fire alarm receiver by preventing the installation of a communication-enabled detector in the pulsating-current type fire alarm receiver from being judged as a communication error or malfunction. [Means for solving the problem]

[0006] To achieve the above objective, the fire detector according to claim 1 of the present invention is a fire receiver from Fire detectors with communication functions connected to the extending district circuit lines And hand, pulse It has a pulsating current detection circuit that detects flow, and further has a communication circuit that can exchange information with the fire alarm receiver, and the pulsating current detection circuit detects when a pulsating current is applied to the district circuit line. thing When this is detected, the communication function of the communication circuit is stopped. vinegar It is characterized by the following.

[0007] According to the fire detector having the above configuration, a pulsating current detection circuit is provided, and when a pulsating current applied to the district circuit line is detected, the communication function can be stopped. This reduces unnecessary operation and thus has the effect of reducing the power consumption of the fire detector.

[0008] Claim 2 before The communication circuit is characterized by stopping the detection of communication abnormalities when the communication function is disabled.

[0009] With a sensor having the configuration described above, even when connected to a pulsating current type receiver, it will not detect communication abnormalities and will have the effect of not outputting unnecessary alarms.

[0010] Before claim 3 Pulse Record The current detection circuit is The voltage applied to the district circuit line is The system is characterized by determining that pulsating current is being applied to a local circuit line when it detects that the current falls below a predetermined threshold at regular time intervals.

[0011] With the configuration described above, pulsating current can be detected in a simple manner, resulting in the advantage of being able to form a pulsating current detection circuit at a low cost.

[0012] Before claim 4 Pulse Record The current detection circuit is characterized by determining that pulsating current is being applied to the local circuit line when it detects a communication anomaly a predetermined number of times consecutively.

[0013] With the configuration described above, pulsating current can be detected in a simple manner, resulting in the advantage of being able to form a pulsating current detection circuit at a low cost. [Effects of the Invention]

[0014] According to the present invention, it becomes possible to use a sensor with a communication function in a pulsating current type receiver, and since sensors can be shared, the number of types of sensors can be reduced, thereby lowering the cost of sensors. Furthermore, the number of types of sensors to be selected is reduced during equipment design and installation, thus reducing the effort required for sensor selection. Furthermore, it can prevent false detections and false alarms of communication anomalies caused by pulsating current, and reduce the power consumption of the sensor. [Brief explanation of the drawing]

[0015] [Figure 1] This figure shows an example configuration of the fire alarm system S. [Figure 2] This figure shows the pulsating current waveform and DC waveform applied to the district circuit line. [Figure 3] This is a block diagram showing the configuration of a pulsating-type fire alarm receiver and detector. [Figure 4] This is a block diagram showing the configuration of a DC type fire alarm receiver and a detector with communication function. [Figure 5]It is a block diagram showing the configuration of a pulsating type fire receiver and a sensor with a communication function.

Embodiments for Carrying out the Invention

[0016] FIG. 1 is a diagram showing a configuration example of a fire alarm system S. The fire alarm system S includes a fire receiver 1 and a plurality of sensors 3. The fire receiver 1 is connected to a plurality of zone circuit lines 2, and is connected to the plurality of sensors 3 via the zone circuit lines 2. The zone circuit lines 2 are external wirings responsible for communication signals and power supply between the fire receiver 1 and the sensors 3. The number of sensors 3 that can be connected to a pair of zone circuit lines 2 is determined by the system, and a plurality of zone circuit lines 2 may be used as necessary. FIG. 1 shows a case where a plurality of zone circuit lines 2-1, 2-2, 2-n are used. The sensor 3 detects smoke and heat generated by a fire as environmental information and generates environmental data.

[0017] The zone circuit line 2 connecting the fire receiver 1 and the sensor 3 serves both as the power supply and communication for the sensor. The fire receiver 1 does not have a smoothing circuit to simplify the power supply circuit, and a pulsating current may be applied to the zone circuit line 2. Here, this is called the pulsating type. At this time, since the connected sensor 3 requires a smoothing circuit for converting the pulsating current to direct current at the input part of the zone circuit line 2, an increase in cost is inevitable. Using a pulsating current on the zone circuit line 2 makes communication difficult, so it is hardly used in recent systems that require communication. However, there are still many pulsating type systems operating in the world. [Explanation of FIG. 2(a)]

[0018] This diagram schematically represents the pulsating waveform of full-wave rectification. From left to right in Figure 2(a), the waveforms represent the fire monitoring period, detector activation (fire detection), recovery pulse, and fire monitoring period (restart). When fire monitoring is performed using pulsating current, detector 3 detects a fire and activates, causing the impedance inside the detector to decrease to an L level. At this time, the L level is approximately 1 to 6V, depending on the characteristics of the switching element inside the detector. When the area circuit line 2 becomes L due to the activation of the detector (fire detection), receiver 1 detects this and issues a fire indicator or alarm. The detector maintains the L level indicating the fire condition.

[0019] After the presence or absence of a fire is confirmed, the operator's recovery operation causes the fire alarm receiver 1 to send a recovery pulse (which stops the power supply to the area circuit line for a predetermined period of time, bringing it to 0V), releasing the self-holding of detector 3, and detector 3 returns to the monitoring state. When detector 3 is self-holding, it releases the self-holding if it detects a recovery pulse. [Explanation of Figure 2(b)]

[0020] This system uses a fire alarm receiver 1 to apply direct current to the district circuit line 2.

[0021] This diagram schematically represents the waveform of the rated voltage of 24V DC. From left to right in Figure 2(b), the waveforms represent the fire monitoring period, the detector activation / communication period, the recovery pulse, and the fire monitoring period (restart).

[0022] When a detector is activated, the impedance inside the detector decreases to an L level. At this time, the L level is approximately 1V to 6V, depending on the characteristics of the switching element inside the detector. When the activation of detector 3 (fire detection) causes the district circuit line 2 to become L, the fire receiver 1 detects this and issues a fire indicator or alarm. After the presence or absence of a fire is confirmed, the operator can perform a recovery operation to send a recovery pulse (which cuts the power supply to the district circuit line for a predetermined time and sets it to 0V), releasing the self-hold of detector 3, and detector 3 returns to the monitoring state.

[0023] The difference here from Figure 2(a) is that, in addition to the difference between pulsating current and direct current, communication takes place during the communication period when the detector is activated. (Only when a detector with communication function and a receiver with communication function are used) During this period, the fire receiver 1 exchanges fire information and individual information of detector 3 with detector 3. In this example, the communication is shown using pulse waveforms. When detector 3 is self-holding, if the district circuit line 2 becomes 0V due to a reset operation of the fire receiver 1, the detector releases its fire self-hold.

[0024] When using a sensor with communication capabilities and a receiver with communication capabilities, the sensor may receive a recovery notification via communication, and at this time, it may release its self-holding mechanism. [Explanation of Figure 3]

[0025] This is a block diagram of a pulsating-current type fire alarm receiver 1 and a pulsating-current type detector 3 using full-wave rectification. The power supply circuit 12 of the fire alarm receiver 1 consists only of a full-wave rectification circuit and does not have a smoothing circuit. Therefore, the voltage waveform generated in the connected district circuit line 2 is a pulsating current with a series of peak-shaped waveforms as shown in Figure 2(a). The pulsating-current type detector 3 is also connected to the district circuit line 2. [Block diagram of fire alarm receiver (Figure 3, left side)]

[0026] The control circuit 13 is a central circuit that receives and exchanges information from the various circuits described later, makes decisions, and issues operation instructions. The fire signal determination circuit 14 is as follows: When the detector 3 detects a fire and turns on the switching circuit 26, the impedance of the zone circuit line 2 drops significantly. A current limiting circuit 11 is provided to protect against damage to the zone circuit line 2 of the fire receiver 1, the switching element of the detector 3, and the power supply circuit 12 of the fire receiver 1, which may occur due to the large current flow caused by the impedance drop. The current limiting value varies depending on the model of the fire receiver 1, but it is generally limited to around 50mA to 100mA.

[0027] The fire signal determination circuit 14 monitors the impedance of the district circuit line 2 and determines that the detector 3 is sending a fire signal when it reaches a predetermined value. Although not shown in the diagram, a terminator is connected to the final end of the district circuit line 2 to monitor for open circuits in the district circuit line 2. The fire signal determination circuit 14 also monitors the current passing through the terminator and determines if there is an open circuit in the district circuit line 3.

[0028] When the fire signal determination circuit 14 determines that there is a fire, the control circuit 13 instructs the alarm circuit 16 and the operation / display circuit 17 to perform actions such as alarm, display, interlocking (not shown), and transmission. The alarm circuit 16 performs alarm actions corresponding to the fire, such as sounding the main sound or district bell, according to instructions from the control circuit 13. The operation / display circuit 17, in accordance with the instructions of the control circuit 13, displays the corresponding information on the panel of the fire alarm receiver 1 and also transmits the operation details of the fire alarm receiver 1's control unit to the control circuit 13. When the operation / display circuit 17 receives a reset operation from the operation unit of the fire alarm receiver 1, the control circuit 13 activates the reset pulse generation circuit 15 and sends a reset pulse to the zone circuit line 2, setting the zone circuit line 2 to 0V for a predetermined time. When the zone circuit line 2 is controlled to 0V, the self-holding of the switching self-holding circuit 26 of the detector 3 is released. [Block diagram of the detector (Figure 3, right side)]

[0029] To obtain power from district circuit line 2, the pulsating current is smoothed by the smoothing circuit 22, and then converted to the required voltage inside the sensor by the constant voltage circuit 23 and supplied. In this example, a reverse current prevention circuit 21 is provided to ensure that the smoothing circuit 22 operates efficiently and to prevent its influence from being transmitted to the district circuit line, thus separating the smoothing circuit 22 from the district circuit line 2.

[0030] The fire detection circuit 25 detects the presence and amount of fire phenomena such as smoke, heat, and flames, and sends fire information to the control circuit 24 if it exceeds a predetermined value.

[0031] When the control circuit 24 detects fire information, it activates the switching circuit 26, which reduces the impedance of the district circuit line 2 and causes it to self-hold. Due to the impedance reduction, the district circuit line 2 becomes low (L), and sends a fire signal to the fire receiver 1. [Explanation of Figure 4]

[0032] Figure 4 is a block diagram of a DC-type fire alarm receiver 1 and a DC-type detector 3 (with communication function). The power supply circuit 12 of the fire alarm receiver 1 is equipped with a DC power supply circuit that can stably supply DC. Therefore, the voltage waveform generated in the connected area circuit line 2 is the DC waveform shown in Figure 2(b). The DC-type detector 3 (with communication function) is also connected to the area circuit line 2. The fact that the fire alarm receiver 1 and detector 3 have a communication circuit is a major difference from the pulsating current type. [Block diagram of the receiver (Figure 4, left side)]

[0033] I will only explain the points that differ significantly from the pulsating flow type. The power supply circuit 12 is a circuit that can output a stable DC current, and this stable DC current is applied to the district circuit line 2. A communication circuit 18 is also installed to receive signals from the district circuit line 2, allowing for detailed fire information to be obtained when the detector 3 is sending out a fire signal. The functions of the other circuits are the same as those of the pulsating current type. [Block diagram of the detector (Figure 4, right side)]

[0034] Similar to the fire alarm receiver 1 described above, only the points that differ significantly from the pulsating current type will be explained. Since DC is applied to the district circuit line 2, a smoothing circuit is not required in the detector's power supply circuit, and it only has a constant voltage circuit 31 that supplies the necessary voltage. Furthermore, it has a communication circuit 35 to communicate with the fire alarm receiver 1 to transmit and receive fire information. The communication circuit 35 starts communication when it detects a communication pulse. Through communication, it transmits fire information, including the unique information of the detector 3, to the fire alarm receiver 1. Also, if it detects an abnormality in the communication waveform or if the communication procedure is not followed, it stores the abnormality information internally as a communication abnormality and sends the stored abnormality information to the fire alarm receiver 1 when communication is resumed.

[0035] Furthermore, in the case of a sensor with a self-diagnostic function, the self-diagnostic results can be transmitted to the receiver 1 via the communication function. The communication protocol will not be discussed here. The functions of the other circuits are the same as those of the pulsating current type.

[0036] [Examples] [Explanation of Figure 5] Figure 5 is a block diagram representing an embodiment of the present invention. [Block diagram of the receiver (Figure 5, left side)] Fire alarm receiver 1 is the same as the pulsating current type shown in Figure 3. The difference here lies in the internal configuration of the connected detector. [Block diagram of the sensor (right side of Figure 5)]

[0037] In addition to the configuration of the detector 3 in the DC type shown in Figure 4, a pulsating current detection circuit 36 ​​is added. As shown in Figure 2(a), in Japan, with pulsating current, points where the voltage becomes 0V appear periodically, approximately every 10ms for a 50Hz AC input and approximately every 8.3ms for a 60Hz AC input. The pulsating current detection circuit 36 ​​constantly monitors the district circuit line 2, and when it detects the above rule, it determines that it is a pulsating current and sends that information to the control circuit 32. When the control circuit 32 receives information that it has detected the pulsating current, the control circuit 32 recognizes that it is connected to the pulsating current type fire alarm receiver 1. From this point onward, the communication circuit 35 is turned OFF, and the communication circuit 35 enters communication OFF mode. While operating in communication OFF mode, it does not perform normal district circuit line communication monitoring or fire information communication, and since unnecessary communication circuits are not activated, current consumption is reduced.

[0038] Furthermore, in the case of a detector with a self-diagnosis function, the self-diagnosis results can be transmitted to the fire alarm receiver 1 via the communication function. However, when the detector recognizes that it is connected to a pulsating-type fire alarm receiver 1, it will also stop transmitting the self-diagnosis results.

[0039] As mentioned above, a method for detecting pulsating current involves detecting points where the voltage becomes 0V at regular intervals; however, a positive voltage pulsating sinusoidal waveform may also be detected.

[0040] Furthermore, if a communication anomaly is detected a predetermined number of times, it may be determined to be a communication anomaly due to pulsating current, and this can be treated as pulsating current detection.

[0041] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes are possible within the scope of its gist. For example, all or part of the apparatus can be configured by functionally or physically distributing and integrating in any unit. Furthermore, new embodiments resulting from any combination of multiple embodiments are also included in the embodiments of the present invention. The effects of the new embodiments resulting from the combinations are combined with the effects of the original embodiments. [Explanation of Symbols]

[0042] S Fire Alarm System 1. Fire alarm receiver 2,2-1, 2-2, 2-n district circuit line 3. Detectors (smoke or heat) 11 Current limiting circuit 12 Power circuit 13 Control circuits 14 Fire signal judgment circuit 15 Recovery pulse generation circuit 16 Alarm circuit 17 Operation / display circuit 18 Communication Circuit 21 Backflow prevention circuit 22 Smoothing circuit 23 Constant Voltage Circuit 24 Control circuits 25 Fire detection circuit 26 Switching Self-Holding Circuit 31 Constant Voltage Circuit 32 Control circuits 33 Fire detection circuit 34 Switching self-holding circuit 35 Communication Circuit 36 Pulsating current detection circuit L Low Level

Claims

1. A fire detector with a communication function connected to a district circuit line extending from a fire alarm receiver, comprising a pulsating current detection circuit for detecting pulsating current, and further comprising a communication circuit capable of exchanging information with the fire alarm receiver, wherein the communication function of the communication circuit is stopped when the pulsating current detection circuit detects that pulsating current is being applied to the district circuit line.

2. The fire detector according to Claim 1, characterized in that the communication circuit stops detecting communication abnormalities when the communication function is stopped.

3. The fire detector according to claim 1 or 2, characterized in that the pulsating current detection circuit determines that a pulsating current is being applied to the district circuit line when it detects that the voltage applied to the district circuit line falls below a predetermined threshold at predetermined time intervals.

4. The fire detector according to claim 1 or 2, characterized in that the pulsating current detection circuit determines that a pulsating current is being applied to the district circuit line when it detects a communication abnormality a predetermined number of times consecutively.

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