JP4878917B2 - Isolator - Google Patents

Description

  The present invention relates to an isolator, and in particular, is connected between a fire receiver and a terminal device connected to each terminal system of the fire receiver, and when a short circuit of the terminal system is detected, the fire receiver and the terminal device The present invention relates to an isolator that cuts off a connection.

As a conventional isolator, for example, “a voltage detection circuit that is used for a sensor line L that connects a sensor and an alarm receiver and monitors its voltage level; a switching circuit that shuts off or restores the sensor line L; This is composed of an address circuit that holds the address, a receiving circuit that receives a control signal from the alarm receiver, and a control circuit that controls the switching circuit (see, for example, Patent Document 1). ).
Japanese Patent No. 3470466 (summary)

  Conventional isolators have not been able to set for each sensor line whether to hold the break or detect self-recovery when a short circuit is detected. Therefore, if an isolator with a shut-off type is installed in a sensor line where transient short-circuiting occurs frequently, the number of alarms increases, and it is possible to respond flexibly to requests for reducing false alarms from on-site maintenance workers. I could not.

  The present invention has been made to solve such problems, and an object of the present invention is to provide an isolator that can arbitrarily switch between shut-off holding and self-recovery.

The isolator according to the present invention is connected between a fire receiver and a terminal device connected to each terminal system of the fire receiver, and detects a short circuit of the terminal system, the fire receiver and the terminal In an isolator that cuts off connection with a device, a disconnect circuit that steadily connects the fire receiver and the terminal device of the terminal system, a short circuit detection circuit that detects a short circuit of the terminal system, and the short circuit A separation control unit for separating the fire receiver and the terminal device of the terminal system by the separation circuit based on a short circuit signal of the detection circuit, and an operation for outputting a separation holding control signal based on the short circuit signal of the short circuit detection circuit and means, when the short-circuit detecting circuit becomes state of not detecting a short-circuit phenomenon, self-condensate of or the disconnecting circuit for holding the disconnected state to the conductive state And whether the cutoff state setting unit is configured to, based on the setting of the short signal and a cutoff state setting unit and a disconnection holding control section for holding the disconnected state by the disconnection circuit, the cutoff state setting unit, the It comprises a switch for connecting the computing means and the separation holding control unit.

The isolator which concerns on this invention WHEREIN: The switch of the said interruption | blocking state setting part is a jumper wire or a short circuit connector.

In the present invention, it is possible to set whether the cut-off state is maintained or self-recovery in the cut-off state setting unit. For this reason, when using an isolator that holds the cut-off state in the fire alarm system, for example, If a transient short-circuit phenomenon frequently occurs in the branch line, only the isolator of the branch line can be easily self-recovered in order to improve safety. Since the setting can be switched in accordance with the situation at the site after the alarm system is operated, it is possible to flexibly respond to a request for reducing false alarms from a maintenance worker at the site.
In addition, the cutoff state setting unit is composed of a switch that connects the calculation means and the disconnection holding control circuit, and when the setting is made so as to hold the disconnection state, the switch is closed and when the setting is made so as to recover itself. Since it is only necessary to open the switch, it can be easily handled by maintenance personnel at the site.

Embodiment 1. FIG.
FIG. 1 is a configuration diagram of an isolator according to Embodiment 1 of the present invention, and FIG. 2 is a configuration diagram of a fire alarm system using the isolator of FIG. The fire alarm system of FIG. 2 includes an isolator provided on a transmission line 11 that connects a fire receiver 10, sensors S1 to Sn such as a fire detector, and the fire receiver 10 and sensors S1 to Sn. 12, 13, 14. The transmission line 11 of this alarm system is branched to branch lines 11a, 11b, and 11c, and a plurality of sensors are connected to the branch lines 11a, 11b, and 11c, respectively, and the branch lines 11a, 11b immediately after the branch point. , 11c, isolators 12, 13, and 14, respectively. The transmission line 11 and the branch lines 11a, 11b, and 11c are each composed of a pair of wires, and power is supplied from the fire receiver 10 to the isolators 12, 13, and 14 and the sensors S1 to Sn. For example, fire signals detected by the sensors S <b> 1 to Sn are multiplexed on the branch lines 11 a, 11 b, 11 c and the transmission line 11 and transmitted to the fire receiver 10. Upon receiving this fire signal, the fire receiver 10 sounds an alarm bell to notify the occurrence of a fire. Further, for example, when the branch line 11a is short-circuited at the point a, the voltage of the branch line 11a is reduced, so that the isolator 12 detects the voltage drop and interrupts the branch line 11a. The isolators 12, 13, and 14 are not necessarily provided immediately after the branch point, and may be provided at predetermined intervals on one transmission line.

  The isolators 12, 13, and 14 in FIG. 2 are configured as shown in FIG. Although the isolator 12 will be described here, the isolators 13 and 14 have the same configuration. The branch line 11 a is composed of a positive conductor 11 a (P) and a negative conductor 11 a (N), which are connected to the transmission line 11. The isolator 12 is connected to the branch line 11a, and protective circuits 21 and 22 made of, for example, surge absorbers are disposed on the input side and the output side thereof, and are separated between the protective circuits 21 and 22. A circuit 23 is arranged. The separation circuit 23 includes a switching element (for example, FET) 24, a resistor 25, a Zener diode 26, and a resistor 27. In a steady state, the switching element 24 is turned on by applying a control voltage between the source and the gate. It is connected to the sensor side.

  A short-circuit detection unit 28 is arranged on the output side of the disconnection circuit 23. The short-circuit detection unit 28 detects the voltage on the output side of the isolator 12, compares it with the reference voltage, and is lower than the reference voltage. In such a case, the short circuit phenomenon is detected assuming that a short circuit phenomenon has occurred in the terminal system on the sensor side. When the short-circuit detection unit 28 detects a short-circuit phenomenon on the sensor side, the short-circuit detection unit 28 cuts off the short-circuit signal and outputs it to the control unit 29. When the disconnection control unit 29 receives a short circuit signal from the short circuit detection unit 28, the disconnection control unit 29 operates the disconnection circuit 23 so that the control voltage is not applied between the source and the gate of the switching element 24 by the FET, and is turned off. The positive conductor 11a (P) of the branch line 11a is cut off and disconnected from the terminal system on the sensor side.

  At this time, the separation control unit 29 outputs a short circuit signal to the CPU 30. When receiving a short circuit signal from the separation control unit 29, the CPU 30 outputs a separation holding control signal for holding the separation to the separation holding control unit 32 via the switch 31. Note that the switch 31 includes, for example, a jumper wire, a short-circuit connector, or the like. When the separation holding control signal is input from the CPU 30, the separation holding control unit 32 holds the cutoff state of the separation circuit 23. Here, if the switch 31 is open, since the separation holding control signal from the CPU 30 is not input to the separation holding control unit 32, the function of holding the cutoff state of the separation circuit 23 will not be exhibited. When the short-circuit signal is not input from the short-circuit detection unit 28, the separation control unit 29 returns the separation circuit 12 to the original state (conduction state).

  In addition, the CPU 30 includes a transmission / reception circuit 33 for transmitting / receiving signals to / from the fire receiver 10 of FIG. 1, and a short / overlap confirmation lamp 34 that blinks when the short circuit is detected and the output side is disconnected. And are connected. A power supply circuit 35 is disposed on the input side of the isolator 12. The power supply circuit 35 includes a diode bridge and a stabilized power supply circuit, and supplies drive power to the short-circuit detection unit 28, the CPU 30, the disconnection holding control unit 32, and the short-circuit / overlap confirmation lamp 34, respectively.

  In the isolator 12 of FIG. 1, the switch 31 corresponds to the cutoff state setting unit of the present invention, the CPU 30 corresponds to the calculation means of the present invention, and the sensors S1 to Sn correspond to the terminal device of the present invention.

Next, the operation when the branch line 11a is short-circuited (see FIG. 2) in a state where the switch 31 of the isolator 12 is closed (the state shown in FIG. 1) will be described.
(A1) When the short circuit phenomenon occurs on the sensor side, the short circuit detection unit 28 detects the voltage drop and detects it, and outputs the short circuit signal to the control unit 29.
(A2) When receiving the short circuit signal from the short circuit detection unit 28, the disconnection control unit 29 turns off the voltage by not applying a voltage between the source and gate of the switching element 24 of the disconnection circuit 23. The positive conductor 11a (P) of 11a is cut off, and the terminal system on the sensor side of the branch line 11a is disconnected.
(A3) The separation control unit 29 also outputs a short circuit signal to the CPU 30. When the CPU 30 receives the short circuit signal, the CPU 30 outputs the separation holding control signal to the separation holding control unit 32 via the switch 31. At this time, the CPU 30 transmits to the fire receiver 10 via the transmission / reception circuit 33 that the short-circuit accident has occurred in the terminal system on the detector side of the branch line 11a, and the fire receiver 10 responds to the short-circuit accident. Alarm is issued.
(A4) When the separation holding control unit 32 receives a control signal from the CPU 30, the separation holding control unit 32 holds the cutoff state of the separation circuit 23. That is, the control voltage is not applied between the source and gate of the switching element 24 of the disconnection circuit 23 so that the off state is maintained. Therefore, for example, even when the short-circuit detection unit 28 does not detect the short-circuit phenomenon (even when the sensor side is restored), the disconnection state of the disconnection circuit 23 continues. In this way, when the shut-off state is maintained, the power is restored by turning it on again.

Next, an operation when the branch line 11a is short-circuited in a state where the switch 31 of the isolator 12 is open and set to self-recovery (non-holding) will be described.
(B1) When the short circuit phenomenon occurs on the sensor side, the short circuit detection unit 28 detects the voltage drop, and detects the short circuit signal and outputs the short circuit signal to the control unit 29.
(B2) The separation controller 29 also outputs a short circuit signal to the CPU 30. When the CPU 30 inputs the short circuit signal, the CPU 30 outputs the separation holding control signal. However, since the switch 31 is open at this time and is not input to the above-described detachment hold control signal detachment hold control unit 32, the detachment hold control unit 32 does not perform its function. At this time, the CPU 30 transmits to the fire receiver 10 via the transmission / reception circuit 33 that the short-circuit accident has occurred in the terminal system on the detector side of the branch line 11a, and the fire receiver 10 responds to the short-circuit accident. Alarm is issued.
(B3) Then, when the short-circuit state of the terminal system on the sensor side of the branch line 11a is resolved and restored, the short-circuit detection unit 28 does not detect the short-circuit phenomenon and does not output a short-circuit signal. When the short-circuit signal from the short-circuit detection unit 28 is not input, the separation control unit 29 applies a control voltage between the source and gate of the switching element 24 of the separation circuit 23 to turn on the separation circuit 23 in a steady state ( Return to the conductive state.

  As described above, in the first embodiment, the switch 31 is provided between the CPU 30 and the detachment holding control unit 32, and it is set whether the severance state of the detachment circuit 23 is maintained or self-recovered by opening and closing the switch 31. For this reason, when using a type of isolator that maintains a shut-off state in a fire alarm system, for example, if a transient short-circuit phenomenon frequently occurs in a specific branch line, the isolator of that branch line Just set up to self-heal only. In this way, according to the situation at the site after the operation of the alarm system, if a short-circuit is detected even once, the cause is surely investigated, and if it is desired to recover, the shut-off is maintained, while the transient short-circuit phenomenon When it is desired to shorten the unmonitored state as much as possible at the time of subsequent recovery, it is possible to switch the setting such as self-recovery, so that it is possible to flexibly respond to the request for reducing false alarms from the maintenance personnel at the site. In addition, since the switching of the setting is whether the switch 31 is closed or opened, it can be easily handled by a maintenance worker on site.

Embodiment 2. FIG.
In the description of the first embodiment, the example in which the short-circuit signal is supplied from the disconnection controller 29 to the CPU 30 has been described. However, the short-circuit signal is directly supplied from the short-circuit detector 28 to the CPU 30. Also good. Moreover, although the example using FET as the switching element 24 of the separation circuit 23 has been described, other switching elements such as a transistor and a latching relay may be used. Moreover, although the example which connected sensors S1-Sn, such as a fire sensor, was demonstrated as a terminal device, in addition to said sensor, a smoke prevention apparatus is also contained in a terminal device.

Embodiment 3. FIG.
In the description of the first embodiment, the example in which the separation control unit 29 supplies the separation holding signal to the separation holding control unit 32 via the CPU 30 and the switch 31 has been described. The short circuit signal may be separated from the control unit 29 via the switch 31 and supplied to the separation holding control unit 32 as a holding signal.

It is the block diagram which showed the structural example of the isolator which concerns on Embodiment 1 of this invention. It is the figure which showed the structural example of the alarm system using the isolator of FIG.

Explanation of symbols

S1-Sn sensor, 10 Fire receiver, 11 Transmission line, 11a, 11b, 11c Branch line, 12-14 Isolator, 21, 22 Protection circuit, 23 Disconnect circuit, 24 Switching element, 25 Resistance, 26 Zener diode, 27 Resistance, 28 Short-circuit detection unit, 29 Disconnection control unit, 30 CPU, 31 Switch, 32 Disconnection holding control unit, 33 Transmission / reception circuit, 34 Short-circuit / duplication confirmation lamp, 35 Power supply circuit.

Claims (2)

Connected between a fire receiver and a terminal device connected to each terminal system of the fire receiver, and when a short circuit of the terminal system is detected, the connection between the fire receiver and the terminal device is cut off. In the isolator,
A disconnect circuit that continually connects the fire receiver and the terminal equipment of the terminal system;
A short circuit detection circuit for detecting a short circuit of the terminal system;
A disconnect control unit that disconnects the fire receiver and the terminal device of the terminal system by the disconnect circuit based on a short circuit signal of the short circuit detection circuit,
Calculation means for outputting a separation holding control signal based on a short circuit signal of the short circuit detection circuit ,
When the short-circuit detection circuit is in a state where it does not detect a short-circuit phenomenon, a cut-off state setting unit that is set to hold a cut-off state or to self-recover the cut-off circuit to a conductive state ;
A separation holding control unit for holding the separation state by the separation circuit based on the setting of the short circuit signal and the interruption state setting unit ;
The shut-off state setting unit is constituted by a switch that connects the calculation means and the separation holding control unit . The isolator according to claim 1, wherein the switch of the cutoff state setting unit is a jumper wire or a short-circuit connector .

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