JP3711466B2 - Fire detector - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fire detector.
[0002]
[Prior art]
Conventional fire detectors commonly used in automatic fire alarm equipment output a fire signal when a fire is detected. The fire signal may be due to voltage drop between the signal lines or constant current discharge. Mostly due to impedance changes.
[0003]
When an external control signal is applied to this general fire detector, a pulse signal is put on the power supply voltage. At this time, the normal fire detector has a circuit configuration as shown in FIG. 5, and the terminals C and L are terminals to which the power supply / signal line is connected and are made nonpolar by the diode bridge 44. . A fire monitoring control circuit 42 as an internal circuit is arranged from these terminals C and L through a diode bridge 44 and a constant voltage circuit 45. Although not shown in detail, the fire monitoring and control circuit 42 mainly includes a fire detection means and a discrimination means, and may further be provided with a test means and the like. In the fire monitoring control circuit 42, a discrimination output (not shown) having a fire discrimination level using a detection value by a fire detection means (not shown) generates a fire output by comparing the detection value with the discrimination level, and the switching circuit 43 is operated. Let
[0004]
At this time, if the output voltage of the constant voltage IC 49 is 3 V in order to make the fire monitoring control circuit 42 operate stably, an output of about 5 V is required from the constant voltage circuit 45 in order to stably output the constant voltage IC 49. It is. In order to stably output the constant voltage circuit 45, about 6.5V must be supplied, and a minimum of about 7.5V is required between the two terminals C and L before the diode bridge 44.
[0005]
[Problems to be solved by the invention]
Thus, when the voltage of each part inside the sensor is seen, it can be seen that the difference between the voltage through the diode bridge 44 and the voltage required for the constant voltage circuit 45 is small. At this time, the minimum voltage supplied from the receiving unit to the two terminals C and L is set to about 9.5 V, and when the pulse signal from the receiving unit is output as a low pulse, it is difficult to detect inside the diode bridge 44. .
[0006]
In addition, when signal transmission is performed using a pulse signal, a transmission circuit for transmitting and receiving a normal pulse signal is provided. However, if a large amount of information is not transmitted and received, it is wasteful to use a highly integrated IC chip. .
[0007]
The present invention is configured so that a fire detector can easily detect a voltage pulse as a signal.
[0008]
[Means for Solving the Problems]
In view of the above points, the first invention provides a fire detection means and a discrimination means based on two terminals to which a signal line to which power is supplied from a receiving unit such as a fire receiver is connected, and the power from the signal line. A fire detector having an internal circuit for performing a fire output based on the output and a switching circuit for outputting a fire signal due to an impedance change between the two terminals to the receiving unit based on the fire output, output from the receiving unit side It has a signal receiving circuit that detects the pulse signal due to the voltage change of the signal line that is output and outputs the signal to the internal circuit, outputs the fire output from the internal circuit to pulse the switching circuit, and outputs the pulse signal to the receiver It is characterized by doing.
[0009]
Therefore, it is not necessary to provide a transmission line in addition to a signal line that also serves as a power source, a pulse signal can be transmitted and received with a simple circuit configuration, and no separate transmission circuit is required.
[0010]
Further, the second invention includes two terminals to which a signal line to which power is supplied from a receiving unit such as a fire receiver is connected, a diode bridge that makes the polarity of the two terminals nonpolar, and a signal line A fire detector having an internal circuit that outputs a fire based on a fire detection means and a discrimination means with a power source, and a switching circuit that outputs a fire signal due to an impedance change between two terminals to the receiver based on the fire output A signal receiving circuit for detecting a pulse signal due to a voltage change of a signal line output from the receiving unit side and outputting the signal to an internal circuit, and the signal receiving circuit is disposed between the diode bridge and the internal circuit. And detecting a high pulse above the power supply voltage.
[0011]
In this way, by receiving a signal based on a high pulse, it is possible to transmit a pulse with a sufficiently different potential without considering the potential inside the sensor.
[0012]
Furthermore, the third invention includes two terminals to which a signal line to which power is supplied from a receiving unit such as a fire receiver is connected, a diode bridge that makes the polarity of the two terminals nonpolar, and a signal line A fire having an internal circuit that performs a fire output based on a fire detection means and a discrimination means by a power source of the power supply, and a switching circuit that outputs a fire signal due to an impedance change between the two terminals to the receiver based on the fire output A sensor comprising a signal receiving circuit for detecting a pulse signal due to a voltage change of a signal line output from the receiving unit side and outputting the signal to an internal circuit, the signal receiving circuit comprising two terminals and a diode bridge; It is arranged between them and detects a pulse signal.
[0013]
Therefore, even if the pulse is not a high pulse, it is possible to transmit a pulse with a sufficiently different potential without considering the potential inside the sensor.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described. FIG. 1 is a circuit diagram showing a first embodiment of a fire detector using the present invention.
[0015]
As shown in FIG. 4, the fire detector according to the first embodiment includes a common line 2 and a line line 3 drawn from a fire receiver 1 provided in a living room in each dwelling of an apartment house such as an apartment. A plurality of fire detectors 4 provided in each room or the like are connected in parallel by a feed wiring to a power / signal line made up of, and a termination resistor 5 is connected to the rear ends of the signal lines 2 and 3.
[0016]
Further, between the fire receiver 1 of the signal lines 2 and 3 and each fire detector 4, a line switching device 6 that always switches and connects the common line 2 and the line line 3 to the fire receiver 1 is arranged. Has been.
[0017]
Normally, each fire detector 4 performs a fire monitoring operation with the power supplied from the fire receiver 1 through the signal lines 2 and 3, and performs a switching operation when a fire is detected to provide a low impedance between the signal lines 2 and 3. It is assumed that the short circuit state of The fire receiver 1 detects a substantially short-circuit state based on the switching operation and performs a fire notification operation. At this time, for example, the fire receiver 1 displays a fire on an outdoor display 10 provided and connected to the entrance, or is not a dwelling unit complete type, and a dwelling unit receiver (not shown) is provided as monitoring control of the entire building. When necessary, it outputs the necessary fire signal to the dwelling receiver.
[0018]
At the time of inspection, the inspection device 12 is connected to the connector 11 drawn out from the line switching device 6 to the outdoor display 10 side, for example. Based on the inspection operation from the inspection device 12, the line switch 6 outputs an inspection start output to the fire receiver 1 via the inspection output line 9, and displays that the inspection is being performed by the fire receiver 1, and each fire detection The signal lines 2 and 3 to the device 4 are disconnected from the fire receiver 1 and connected to the inspection device 12. In this state, the fire receiver 1 performs an inspection display based on the inspection start output of the line switching device 6 and enables an outdoor inspection from the inspection device 12. At this time, each fire detector 4 is operated by the power supply voltage supplied from the inspection device 12 through the signal lines 2 and 3.
[0019]
In FIG. 1, terminals C and L are terminals to which the power / signal lines 2 and 3 are connected, and are made nonpolar by the diode bridge 44. A fire monitoring control circuit 42 as an internal circuit is arranged from these terminals C and L through a diode bridge 44 and a constant voltage circuit 45. Specifically, for example, as shown in FIG. 5, the constant voltage circuit 45 supplies a constant voltage by combining a transistor Q3 and a resistor R1 based on the Zener voltage of the Zener diode Z2. Although not shown in detail, the fire monitoring control circuit 42 mainly includes a fire detection means and a discrimination means, and may further be provided with a test means. In the fire monitoring control circuit 42, a fire output is generated by, for example, comparing a detection value with a discrimination level by a discrimination unit (not shown) having a fire discrimination level using a detection value by a fire detection unit (not shown). In order to ensure the operation, a constant voltage IC 49 is provided to maintain a constant voltage inside the sensor.
[0020]
Fire detection means (not shown) uses heat detection due to fire using, for example, a thermistor, smoke detection due to a photoelectric fire consisting of a light emitting element and a light receiving element, and other means for detecting infrared rays, gas or odor due to fire. It is done. The discrimination means (not shown) may be a comparator that compares a detection value from a fire detection means (not shown) with a reference level, or a microcomputer that AD-converts the detection value and processes data.
[0021]
In addition, an oscillation circuit 41 such as a charging / discharging time constant constituting a CR circuit (not shown) for taking fire monitoring timing is provided at the same position as the fire monitoring control circuit 42.
[0022]
A switching circuit 43 is configured between the terminals C and L and the diode bridge 44 and the fire monitoring control circuit 42. The switching circuit 43 is, for example, the same circuit as shown in FIG. 5 and receives a fire output from the fire monitoring control circuit 42 to switch between terminals C and L in a substantially short-circuited state. It is turned on by supplying a base voltage to the transistor Q1 as an element. At this time, the Zener diode Z1 as a voltage holding element maintains a voltage required after the constant voltage circuit 45. Further, when the transistor Q1 is turned on, the transistor Q2 is also turned on, and the light-emitting diode L1 that externally displays that the fire detector 4 has detected a fire is turned on. The switching circuit 43 changes the impedance between the signal lines C and L by performing a voltage lowering operation, outputs the change in impedance as a fire signal, and the fire receiver 1 detects the fire signal. .
[0023]
Further, an internal receiving circuit 46 as a signal receiving circuit that detects voltage pulses transmitted from the inspection device 12 onto the signal lines 2 and 3, for example, is provided on the terminals C and L side of the constant voltage circuit 45. The internal receiving circuit 46 has a Zener diode Z3 for detecting a potential rise in the internal circuit between the diode bridge 44 and the constant voltage circuit 45, and is configured to turn on the transistor Q4 when the potential rises. Has been. A current flows through the Zener diode Z3 line when the internal potential is constantly exceeded, and the Zener diode Z3 operates reliably when the high pulse is applied to the power supply voltage, and is always off, so that current consumption does not increase. While the transistor Q4 is on, a low level is inputted to a port of a microcomputer (not shown) in the fire monitoring control circuit 42, and on / off synchronized with the pulse is inputted.
[0024]
Here, the operation of the entire system will be briefly described. The power supply voltage from the fire receiver 1 is normally supplied to the terminals C and L of the fire detectors 4 through the signal lines 2 and 3. And if the fire detector 4 which detects a fire exists, the switching circuit 43 will be operated and a fire signal will be sent out to the fire receiver 1 by making the signal lines 2 and 3 into a substantially short circuit state. When the system is inspected, the power supply voltage to the signal lines 2 and 3 is supplied from the inspector 12, and although not described in detail, an inspection signal is output from the inspector 12 to the fire receiver 1.
[0025]
Regarding the signal transmission procedure from the outdoor inspection device 12 and the specific form of the pulse, the signal transmission procedure first sends a preparation signal to cause each fire detector 4 to recognize that transmission is started, and represents a header indicating the head. The signal, the control code signal indicating the content of the inspection to be requested, the address signal designating each fire detector 4 individually, and the footer signal indicating the end as one control unit are individually applied to each fire detector 4. Therefore, it sends out while changing the number of addresses that can be connected. Finally, an END signal is sent that causes each fire detector 4 to recognize that transmission is to end. During this signal transmission, each fire detector 4 performs the inspection operation indicated by the control signal of the control unit at the timing of the footer signal when the address signal of the control unit matches its own address. The designated fire detector 4 responds by transmitting a response signal of its own address signal and normal signal or abnormal signal at a timing provided before the next header signal (finally the END signal).
[0026]
Next, regarding a specific form of the transmission signal, first, the preparation signal continues a steady potential of, for example, 1 second or more, and then forms a positive pulse in a width of, for example, 30 milliseconds, and continues the steady potential, for example, 500 milliseconds. To do. In response to this preparation signal, each fire detector 4 prepares for transmission by interrupting the operation currently being processed. At this time, the width of the pulse needs to be a width that can be reliably detected during operation of the fire detector 4. The header signal and the footer signal continue a pulse having a width of, for example, 12 milliseconds and a steady potential of, for example, 200 milliseconds. The rise of the first pulse is the same for other signals, but indicates the end of the stationary potential of the immediately preceding signal. The pulse such as the header signal is the code signal part indicating the control code and address described below. The shape is different from the pulse. This facilitates distinction from a signal portion for which a control code or an address is desired. For the code signal portion indicating the control code and the address, a pulse having a width different from that of the header signal or the like, for example, 3 ms is formed, and the time of the subsequent steady potential is set to a width indicating “0”, for example, 12 ms. Alternatively, a width indicating “1”, for example, 24 msec. The combination of “0” and “1” represents the control code and address. For example, in the control code, 2 bits represent various modes at the time of inspection, and the address is 4 bits from address 1 to address 10 Represents. Therefore, the code signal portion in this case is 6 bits. For the code signal portion, the control code portion is “01” and the address portion is “0001”, so that the fire detector at address 1 is designated to operate in the inspection mode, the control code portion is “01”, and the address portion is In “1010”, the fire detector at the address 10 is designated to perform the operation in the inspection mode.
[0027]
Each fire detector 4 receives the code signal as described above from the internal reception circuit 46 with respect to the inspection device 12, and the fire monitoring control circuit 42 determines the control contents. The addressed fire detector 4 performs the process specified in the control code and generates a low pulse with respect to the power supply voltage by causing the switching circuit 43 to perform a pulse operation. It responds by transmitting a response signal including Then, the outdoor inspection device 12 recognizes that the fire detector 4 at the corresponding address has some abnormality by receiving no signal at the response timing of the fire detector 4 or receiving an abnormal signal.
[0028]
In such a transmission system of timing, signal transmission by pulse operation of the switching circuit 43 is sufficient, and it is not necessary to configure a complicated transmission circuit. Further, by configuring the transistor Q1 of the switching circuit 43 with a photocoupler, it is possible to increase the pulse speed by the switching circuit 43. Further, it is easy to distinguish between transmission and reception from the fire detector 4. Next, a second embodiment of the present invention will be described. FIG. 2 is a circuit diagram showing a second embodiment of a fire detector using the present invention.
[0029]
The fire detector according to the second embodiment has the same system as shown in FIG. 4 as the fire detector of the first embodiment.
[0030]
In FIG. 2, as in FIG. 1, terminals C and L, an oscillation circuit 41, a fire monitoring control circuit 42, a diode bridge 44, a constant voltage circuit 45, and a constant voltage IC 49 are provided. In place of the internal receiving circuit 46 in FIG. 1, an external signal receiving circuit that detects voltage pulses transmitted from the inspection device 12 to the signal lines 2 and 3 on the terminals C and L side of the diode bridge 44, for example. A receiving circuit 47 is provided. The external receiving circuit 47 constitutes a detection line that is connected to the ground line of the internal circuit from both terminals C and L via the diodes DC and DL from the point that does not affect the potential of the internal circuit outside the diode bridge 44. Regardless of whether the positive electrode is the terminal C or L, the transistor Q5 is turned on and off when the potential of the power supply voltage exceeds a predetermined voltage.
[0031]
With such a circuit configuration, when the voltage between the terminals C and L rises due to a high pulse, current flows through the divided resistors R2 and R3 provided on the detection line via the diode DC or DL, and the base current does not flow through the transistor Q5. Therefore, the high level is supplied to the microcomputer which is turned off and not shown in detail in the fire monitoring control circuit 42. As the voltage between the terminals C and L decreases, the potential of the dividing resistor decreases, and the transistor Q5 is turned on to supply a low level to a microcomputer not shown in detail. The transistor Q5 is configured to be turned on when a high pulse is detected. Needless to say, the same configuration may be used when the transistor Q5 is turned off with a low pulse based on the setting of the dividing resistor. Thus, by detecting the voltage between the terminals C and L from the outside of the diode bridge 44, the operation inside the sensor 4 is not affected by the reception of the pulse.
[0032]
Also in the fire detector of the second embodiment configured as described above, the power supply operates by pulsing the switching circuit 43 by acting in the operation of the system similarly to the fire detector of the first embodiment. Similarly, it is possible to respond by generating a low pulse with respect to the voltage and transmitting a response signal to the checker 12, and it is not necessary to separately configure a complicated transmission circuit.
[0033]
Finally, FIG. 3 is a circuit diagram showing a third embodiment of the fire detector using the present invention for the third embodiment in which the present invention is implemented, but the circuit configuration is almost the same as FIG. 2 is different from FIG. 2 in that an external receiving circuit as a signal receiving circuit that detects voltage pulses transmitted from the checker 12 or the like to the signal lines 2 and 3 on the terminals C and L side of the diode bridge 44. 48, the external receiving circuit 48 constitutes a detection line in which the external receiving circuit 47 is connected to the ground line of the internal circuit from both terminals C and L via diodes DC and DL. The detection lines connected from the terminals C and L to the ground line of the internal circuit via the limiting resistors RC and RL are configured. The transistor Q6 is turned on and off when the potential of the supplied voltage exceeds a predetermined voltage regardless of whether the positive electrode is the terminal C or L. When the voltage between the terminals C and L rises due to a high pulse, the potential between the resistors RC and RL becomes half, but when the voltage exceeds a predetermined voltage level, the current flowing through the divided resistors R4 and R5 of the detection line Since the base current does not flow to the transistor Q6, the transistor Q6 is turned on and off as in the second embodiment, and a high level is supplied to the microcomputer not shown in detail in the fire monitoring control circuit 42.
[0034]
Also in the fire detector of the third embodiment configured as described above, the power supply operates by pulsing the switching circuit 43 by acting in the operation of the system similarly to the fire detector of the second embodiment. Similarly, it is possible to respond by generating a low pulse with respect to the voltage and transmitting a response signal to the checker 12, and it is not necessary to separately configure a complicated transmission circuit.
[0035]
In the third embodiment, as compared with the second embodiment, the limiting resistances RC and RL are arranged on the detection line from between the terminals C and L, so that the impedance always remains and current flows. Therefore, there is an advantage that the signal can be easily detected. In addition, the second embodiment has an advantage that the threshold potential at which the transistor Q5 operates can be set lower and less susceptible to noise than the third embodiment.
[0036]
In the system of each embodiment described above, the input by signal transmission to each fire detector 4 may be not only the inspection operation but also data setting, and the operation control is not from the inspection device 12 but of the fire receiver 1. Such a receiving unit may be used. Further, although the transmission signal is used as the response signal from the fire detector 4, a switching operation or the like at a predetermined interval is also possible. Further, the switching operation may use an impedance change such as constant current control.
[0037]
As described above, the first invention detects the pulse signal due to the voltage change of the signal lines 2 and 3 output from the receiving unit side such as the fire receiver 1 and the inspection device 12 to detect the pulse signal as in the fire monitoring control circuit 42. A signal receiving circuit such as an internal receiving circuit 46 or an external receiving circuit 47, 48 for outputting a signal to the internal circuit is provided, a fire output is pulsed from the internal circuit and the switching circuit 43 is pulsed to receive a pulse signal. There is no need to provide a transmission line in addition to a signal line that also serves as a power source, a pulse signal can be transmitted and received with a simple circuit configuration, and no separate transmission circuit is required.
[0038]
Further, the second invention detects an internal circuit such as a fire monitoring control circuit 42 by detecting a pulse signal due to a voltage change of the signal lines 2 and 3 output from the receiving unit side such as the fire receiver 1 and the inspection device 12. A signal receiving circuit such as an internal receiving circuit 46 that outputs a signal to the signal receiving circuit, the signal receiving circuit is disposed between the diode bridge 44 and the internal circuit, and detects a high pulse above the power supply voltage, In this way, by receiving a signal due to a high pulse, it is possible to transmit a pulse with a sufficiently different potential without considering the potential inside the sensor.
[0039]
Further, the third invention detects an internal circuit such as the fire monitoring control circuit 42 by detecting a pulse signal due to a voltage change of the signal lines 2 and 3 output from the receiving unit side such as the fire receiver 1 and the inspection device 12. Are provided between the two terminals C and L and the diode bridge 44 to detect a pulse signal. Therefore, it is possible to correspond to either a high pulse or a low pulse, and it is possible to transmit pulses at a sufficiently different potential without considering the potential inside the sensor.
[Brief description of the drawings]
FIG. 1 is a circuit diagram of a fire detector according to a first embodiment using the present invention.
FIG. 2 is a circuit diagram of a fire detector according to a second embodiment similar to FIG.
FIG. 3 is a circuit diagram of a fire detector according to a third embodiment similar to FIG. 1;
FIG. 4 is a schematic configuration diagram of the entire system.
FIG. 5 is a circuit diagram of a conventional fire detector.
[Explanation of symbols]
42 Fire monitoring control circuit 43 Switching circuit 44 Diode bridge 45 Constant voltage circuit 46 Internal reception circuit 47, 48 External reception circuit

Claims (4)

Based on fire detection means and discrimination means by two terminals to which a signal line to which power is supplied from the receiving unit is connected, a diode bridge for making the polarities of the two terminals non-polarized, and power from the signal line A fire detector having an internal circuit for performing a fire output, and a switching circuit for outputting a fire signal due to an impedance change between the two terminals to the receiving unit based on the fire output,
Internal reception that is arranged between the diode bridge and the internal circuit, detects a pulse signal above the power supply voltage due to a voltage change of the signal line output from the reception unit side, and outputs a signal to the internal circuit With a circuit,
A fire detector, wherein the switching circuit outputs a pulse signal to the receiving unit by pulse-outputting a fire output from the internal circuit and causing the switching circuit to perform a pulse operation. Based on fire detection means and discrimination means by two terminals to which a signal line to which power is supplied from the receiving unit is connected, a diode bridge for making the polarities of the two terminals non-polarized, and power from the signal line A fire detector having an internal circuit for performing a fire output, and a switching circuit for outputting a fire signal due to an impedance change between the two terminals to the receiving unit based on the fire output,
An external receiving circuit that is arranged between the two terminals and the diode bridge, detects a pulse signal due to a voltage change of the signal line output from the receiving unit side, and outputs a signal to the internal circuit;
A fire detector, wherein the switching circuit outputs a pulse signal to the receiving unit by pulse-outputting a fire output from the internal circuit and causing the switching circuit to perform a pulse operation.   The fire detector according to claim 2, wherein the external receiving circuit monitors a voltage between each of the two terminals and the diode bridge and to a ground line inside the diode bridge. Based on fire detection means and discrimination means by two terminals to which a signal line to which power is supplied from the receiving unit is connected, a diode bridge for making the polarities of the two terminals non-polarized, and power from the signal line A fire detector having an internal circuit for performing a fire output, and a switching circuit for outputting a fire signal due to an impedance change between the two terminals to the receiving unit based on the fire output,
A signal receiving circuit for detecting a pulse signal due to a voltage change of the signal line output from the receiving unit side and outputting the signal to the internal circuit, the signal receiving circuit comprising: the two terminals and the diode bridge; A fire sensor arranged between and detecting a pulse signal.

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