JP2802014B2 - Telephone circuit of disaster prevention monitoring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telephone circuit of a disaster prevention monitoring device for communicating with a terminal connected by a telephone line.

[0002]

2. Description of the Related Art Conventionally, as a telephone circuit of a main disaster prevention monitoring device, there is, for example, a telephone circuit shown in FIG. In FIG. 4, reference numeral 10 denotes a receiver, which monitors and receives detection information from a fire detector or a transmitter provided in a guard area via a signal line.
A receiver circuit unit 54 for judging a fire and giving an alarm is provided. A telephone line 42 composed of a positive T line and a negative TC line is drawn out from the receiver 10 to the terminal side, and is connected to a jack terminal 62 provided in the transmitter 25 installed on the terminal side.

In the telephone circuit of the receiver 10, a jack terminal 56 for connecting a telephone for the receiver is AC-coupled to the telephone line 42 via a capacitor C1. Further, a DC voltage from the receiver power supply 52 to the receiver circuit unit 54 is applied to the primary side and the secondary side of the capacitor C1 by the resistors R11 and R12 via the diode D1, respectively.
6, 62 are respectively DC biased.

For a call between the receiver 10 and the transmitter 25 on the terminal side, a plug of a telephone for the receiver is inserted into the jack terminal 56 of the receiver 10, and a plug of the portable telephone is connected to the transmitter. By inserting it into the 25 jack terminals 62, it becomes possible to talk. Note that the telephone on the receiver 10 side has a jack terminal 5
In some cases, a telephone is directly connected without providing the same.

[0005]

However, in the telephone circuit of such a conventional disaster prevention monitoring device, an AC line is erroneously connected to a telephone line drawn from a receiver at the time of construction.
In some cases, a 100 V line was connected. This causes an accident of incorrect connection because AC lines and various signal lines for disaster prevention are wired on the ceiling or the back side of the wall at the time of construction.

When the AC power is turned on in a state where the AC line is erroneously connected to the telephone line, the AC power is applied to the receiver via the telephone line.
There is a problem that the circuit inside the receiver is destroyed due to the sneaking around 0 V, and the receiver is seriously damaged. In this case, if it is determined that the cause of the circuit destruction is due to the sneak of AC power from the telephone line, it is possible to specify the inspection location and take a countermeasure. However, if the receiver is turned on and does not operate, it is not known that circuit destruction has occurred due to AC power from the telephone line. Inspection, and further inspection of transmission lines, repeaters, fire detectors, and the like must be performed, and there is a problem that the inspection is complicated and repair requires a lot of time and labor.

[0007] The present invention has been made in view of such a conventional problem, and minimizes the destruction of a circuit in a receiver due to erroneous connection of an AC power supply to a telephone line. It is an object of the present invention to provide a telephone circuit of a disaster prevention monitoring device which can notify a user to easily understand the cause and take appropriate measures after an accident.

[0008]

In order to achieve this object, the present invention is configured as follows. The reference numerals in the drawings of the embodiments are also shown. First, according to the present invention, a receiver side connected to a telephone line 42 by receiving a DC bias by a DC power supply voltage of a common receiver power supply 52 and a receiver circuit unit 54 for receiving a detection information from a terminal and monitoring a fire. It is intended for a telephone circuit of a disaster prevention monitoring device that makes a call between the telephone 40 and the terminal-side telephone 48.

According to the present invention, the telephone circuit of such a disaster prevention monitoring device is provided with a jack terminal (telephone terminal) 56 of the receiver telephone 40 on the positive line T of the telephone line 42.
Is connected via a first capacitor C1 for AC coupling and a diode D2 for a reverse current element, and the other end of a jack terminal (telephone terminal) 56 is connected to the minus line TC of the telephone line 42 for AC coupling. Connected via the second capacitor C2, when a reverse voltage having a positive polarity on the negative side is applied to the telephone line 42, the positive line of the telephone line 42 passes through the primary side and the secondary side of the second capacitor C2. A bypass circuit for supplying a current to T is provided, and the bypass circuit is provided with fuse means for opening the circuit by disconnection with a current exceeding a prescribed value.

Further, according to the present invention, the line TC on the negative side of the telephone line 42 is connected to a DC power supply through a high resistance, and the DC voltage on the line TC on the negative side is monitored to detect a line abnormality when the voltage rises to a predetermined value or more. Line abnormality detector 5 for detecting and outputting
0, and a notifying unit 66 for notifying the disconnection of the fuse unit when the detection output of the line abnormality detecting unit 50 is obtained.

Here, fuse resistors 58 and 60 are used as fuse means. The fuses 68 and 70 and the resistor R
A series circuit with R7 and R8 may be provided.

[0012]

According to the telephone circuit of the disaster prevention monitoring device of the present invention having such a configuration, even if the AC line is erroneously connected to the telephone line at the time of construction and started up, the AC power supply from the telephone line can be performed. In response to this, a bypass current flows through the fuse means of the telephone circuit in the receiver, causing a disconnection, and protects other circuits that share a power supply with the telephone line side from the application of an AC voltage.

[0013] Further, since a line abnormality is detected by a voltage drop due to the fuse disconnection and the fuse disconnection is notified, when the receiver is turned on and started, the telephone circuit is used in the first processing after initialization. Is notified, it is immediately known that an accident has occurred due to an erroneous connection of the AC power supply to the telephone line, and the inspection place can be specified, so that countermeasures after the accident can be easily taken.

[0014]

FIG. 1 is a block diagram showing an overall configuration of a disaster prevention sensing device to which a telephone circuit according to the present invention is applied. In FIG. 1, reference numeral 10 denotes a receiver, from which a transmission line 12 is drawn out, and the transmission line 12
4, an analog smoke sensor 16, an analog heat sensor 18, and a control repeater 20 are connected. Repeater for sensor 14
Further, a sensor line 22 is drawn out, and connects the on / off sensor 24 and the transmitter 25.

The transmitter 25 is provided with a push button switch 26, and further provided with a jack terminal 44 for connecting a portable telephone 48 for communicating with the receiver 10 via a plug 46. The on / off sensor 24 short-circuits the sensor line 22 from the sensor repeater 14 to a low impedance when a fire is detected. Further, the operation of the push button switch 26 of the transmitter 25 short-circuits the sensor line 22 to low impedance.

Upon receiving a call from the receiver 10 specifying the terminal address, the sensor repeater 14 responds with the fire detection information of the on / off sensor 24 or the transmitter 25 detected at this time. Also, the fire detection information receiver 10
In order to promptly transmit to the receiver, an interrupt signal is transmitted to the receiver 10 when a fire is judged by the sensor repeater 14, and fire detection information of the on / off sensor 22 or the transmitter 25 is collected by the interrupt processing. You can also.

The analog smoke detector 16 and the analog heat sensor 18 respond to the call from the receiver 10 specifying the terminal address, with the analog detection information detected at this time. In addition, the analog detection information is compared with the fire level, and the same fire judgment as that of the on / off sensor 24 is made. This fire judgment can be transmitted to the receiver 10 by interruption similarly to the relay unit 14 for the sensor.

A control line 28 is connected to the control repeater 20.
Connects the control load 30. As the control load 30, an appropriate load such as a district bell or a smoke prevention device is connected.
The control repeater 20 receives a control command specifying a terminal address from the receiver 10 and drives the control load 30. Further, the status of the control load 30 can be responded to a call command from the receiver 10 specifying a terminal address.

The receiver 10 is provided with a control CPU 32, which leads out the transmission line 12 via a transmission input / output unit 34. The control CPU 32 collects the terminal information by a call specifying the terminal address, and performs monitoring judgment on whether or not there is a fire. When the fire is judged, an alarm is displayed on the display unit 36, and the control repeater 20 is notified. A control command for driving the control load 30 is sent.

Further, the receiver 10 is provided with a telephone circuit section 38. A telephone line 42 is drawn from the telephone circuit section 38 toward the terminal, and the telephone line 42 is connected to a jack terminal 44 of the transmitter 25. Telephone circuit section 3 of receiver 10
A telephone 40 is connected to 8. The telephone 40 may be connected to the jack terminal by a plug, or may be fixedly connected.

A receiver power supply 52 provided in the receiver 10 supplies a DC power supply voltage to the control CPU 32, the transmission input / output unit 34, and the display unit 36, and simultaneously supplies the same DC power supply voltage to the telephone circuit unit 38, The DC bias of the telephone circuit unit 38 and the telephone line 42 is performed. As will be described later, a bypass circuit is formed in the telephone circuit unit 38 for applying an AC power supply when the AC power supply 100V or the like is erroneously connected to the telephone line 42, and a current flows through the fuse means. A protection circuit is provided to prevent the application of the AC power supply which is disconnected and erroneously connected by the telephone circuit unit 38.

Further, the receiver 10 is provided with a line abnormality detecting section 50. The line abnormality detecting section 50 detects an abnormality of the line voltage caused by disconnection of the fuse means when the AC power supply is erroneously connected to the telephone line 42, and outputs the abnormality to the control CPU 32. The control CPU 32 that has received the abnormality detection output from the line abnormality detection unit 50 displays on the fuse disconnection notification unit 66 of the display unit 36 that the fuse cut has occurred in the telephone circuit unit 38.

FIG. 2 is a circuit block diagram showing a first embodiment of the telephone circuit of the present invention. In FIG. 2, a DC power supply voltage from a receiver power supply 52 is applied to a receiver circuit unit 54 and supplied to a signal line of a transmission line, and also supplies power to a terminal. Further, power is supplied to the illustrated telephone circuit via the diode D1. The telephone circuit AC-couples one end of the jack terminal 56 to the T line of the telephone line 42 via the first capacitor C1. A diode D2 for preventing backflow is inserted in a connection line formed by the capacitor C1. The other end of the jack terminal 56 is also connected to the second terminal.
AC-coupled to the TC line of the telephone line 42 via the capacitor C2. The primary side of the capacitor C1 to which the jack terminal 56 is connected is connected to a positive power supply line from the diode D1 via the resistor R1 and is DC-biased.

At the same time, the secondary side of the capacitor C1 also has a resistance R
2 is connected to the plus side of the receiver power supply 52 via the DC power supply 2 so as to be DC biased. Furthermore, in the telephone circuit of the present invention, the DC line is also applied to the connection side of the TC line of the telephone circuit so that the T line and the TC line are balanced lines.
For this reason, the second capacitor C that performs the AC connection on the TC line side
2 is connected to the negative side of the receiver power supply 52 via a resistor. In the present invention, the fuse resistors 58 and 6 are used as the connection resistance.
0 is used to DC bias the primary and secondary sides of the capacitor C2.

Further, the minus sides of the fuse resistors 58 and 60 are connected to the plus TC line via a diode D3. In this embodiment, the output of the diode D3 is connected to the cathode side of the diode D2. The circuit in which the diode D3 is inserted forms a bypass circuit for bypassing a reverse voltage applied with the TC line as a plus side when the AC power supply 100 is erroneously connected to the telephone line 42.

Further, a line abnormality detecting section 50 of the telephone line 42
A comparator 64 is provided. The line on the TC line side is connected to the plus input terminal of the comparator 64 via a high resistance R4, and this line is pulled up by the receiver power supply 52 via the high resistance R3. The reference voltage Vre is applied to the minus input terminal of the comparator 64 by the voltage division of the resistors R5 and R6.
f is set.

The comparator 64 detects the line abnormality of the telephone line 42 and, at the same time, detects the connection of the telephone to the jack terminal 62 of the transmitter 25 in the steady monitoring state. That is, when the fuse resistors 58 and 60 are in a normal steady monitoring state, a DC voltage determined by the high resistance R3 and the divided voltage of the fuse resistor 60 is applied to the TC line, and the fuse resistor 60
Is small, the line voltage of the TC line is at a very low voltage.

On the other hand, when a telephone is connected to the jack terminal 62, the impedance of the telephone is sufficiently low with respect to the high resistance R3. Therefore, the TC line as a divided voltage is determined by the impedance of the telephone and the resistance of the fuse resistor 60. Voltage rises. The reference voltage Vref of the comparator 64 is set slightly lower with respect to such an increase in the line voltage of the TC line when the telephone is connected. Therefore, when the telephone is connected to the jack terminal 62, the comparator 64 is set to the H level. Produces an output.

The H level output from the comparator 64 is controlled by the control CP
When U32 receives the message, the connection of the telephone set in the transmitter 25 is displayed on the display unit 36, and the call control of the telephone set provided in the receiver is performed. On the other hand, when the fuse resistors 58 and 60 are disconnected when the AC power supply 100 is erroneously connected to the telephone line 42,
The power supply voltage is directly applied to the TC line via the high resistance R3, and when the voltage of the TC line exceeds the reference voltage Vref, the comparator 64 generates an H level output.

As described above, the disconnection of the fuses 58 and 60 is caused by the erroneous connection of the AC power supply 100 during construction.
Fuse resistance 5 when starting up by turning on the power of receiver 10
If the H level output of the comparator 64 is obtained due to the disconnection of 8, 60, and therefore the H level output of the comparator 64 is obtained immediately after the initialization processing, the control CPU 32 sets the fuse resistors 58, 6
It is determined that the disconnection is 0, and the notification operation by the fuse disconnection notification unit 66 can be performed.

Next, the operation of the first embodiment shown in FIG. 2 will be described.
It is assumed that the AC power supply 100, for example, AC 100V is erroneously connected between the T line and the TC line of the telephone line 42 at the construction stage where the receiver power supply 52 of the receiver 10 is not turned on, and the AC power supply 100 is started. I do. Therefore, an AC voltage from the AC power supply 100 is applied to the telephone circuit via the telephone line 42. Of the AC voltage, for a half cycle in which the TC line side is positive, the flow of the AC current in the telephone circuit can be prevented by the diode D2.

Next, regarding the half cycle of the AC voltage applied to the reverse polarity with the TC line as the plus side, as shown by the arrows, the capacitor C2, the fuse resistor 58, the diode D3,
A bypass path is formed to flow to the T line through D2, and a bias path is formed to flow an alternating current to the T line through the fuse resistor 60 and the diodes D3 and D2. Here, since the resistance values of the fuse resistors 58 and 60 are small, the fuse portions of the fuse resistors 58 and 60 are blown by the application of AC 100 V, and the circuit connection to the receiver power supply 52 on the TC line side can be cut off. Therefore, the AC voltage from the telephone line 42 is not directly applied to the receiver circuit unit 54, and the receiver circuit unit 54 can be completely protected.

Next, the AC power supply 10 for the telephone line 42
If the receiver power supply 52 of the receiver 10 is turned on in a state where the fuse resistors 58 and 60 are disconnected due to the erroneous connection of 0, the fuse resistors 58 and 60 are disconnected.
The power supply voltage + to the TC line of the telephone line 42 via the high resistance R3
When the line voltage of the TC line exceeds the reference voltage Vref, the comparator 64 generates an H level output.

The control CPU 32 takes in the H level output of the comparator 64 in the reproduction process after the initialization process is completed by turning on the receiver power supply 52. Judgment is made and the fuse disconnection notifying section 66 of the display section 36 is activated to notify. For this reason, the notification by the fuse disconnection notification unit 66 is performed when the power supply of the receiver 10 is turned on, so that it is possible to immediately determine that a failure has occurred due to the incorrect connection of the AC power supply 100 to the telephone line 42.

Therefore, it is checked whether or not an AC voltage is applied to the telephone lines T and TC lines.
A measure can be taken to disconnect the incorrectly connected AC power supply 100. Further, an AC power supply 1 for the telephone line 42
If it is confirmed that the erroneous connection of 00 has been eliminated, the fuse resistors 58 and 60 and the capacitor C2 provided in the telephone circuit may be replaced.

Further, as the circuit elements provided in the telephone circuit by applying an AC voltage, resistors R1 to R4, a capacitor C1,
Further, the diodes D1 to D3 are checked to determine whether there is a failure. Further, the illustrated telephone circuit is provided on an independent printed circuit board that can be separated from the other receiver circuit unit 54 and connected to a connector. If the blown fuse is notified, the printed circuit board of the telephone circuit is replaced with a new one. It may be exchanged.

FIG. 3 is a block diagram showing a second embodiment of the present invention. In this embodiment, a resistor R7 and a fuse 68 are used instead of the fuse resistor used in the first embodiment of FIG. 2 and a series circuit of a resistor R8 and a fuse 70, and the other configuration is the same as that of the first embodiment of FIG. The resistors R7 and R8 have the same resistance values as the fuse resistors 58 and 60 shown in FIG.

As the fuses 68 and 70, replaceable fuses mounted on a fuse holder are used. In the second embodiment shown in FIG. 3, the fuses 68 and 70 when the AC power supply 100 is erroneously connected to the telephone line 42 are connected.
The fuse can be easily replaced for the disconnection.
In the above embodiment, the case where the receiver 10 is provided is taken as an example. However, as the receiver, a receiver and a relay board functioning as a local receiver are connected to the transmission path from the receiver, and a terminal is provided for each relay board. It also includes a relay board with a configuration connected to it.

In the above embodiment, the case where an AC power supply is erroneously connected to a telephone line during construction or the like is taken as an example. For example, a transmission line used in a building monitoring system is erroneously connected and connected to the telephone line. Of course, it operates effectively even when a voltage of the opposite polarity is applied.

[0040]

As described above, according to the present invention, even if an AC power supply or the like is erroneously connected to a telephone line during construction or the like, the circuit section in the receiver can be reliably prevented from being applied with an AC voltage or the like. To prevent damage to the circuit and minimize damage caused by erroneous connection of the telephone line to an AC power supply or the like.

Also, when the receiver is started up, a blown fuse caused by an erroneous connection of an AC power supply or the like to a telephone line is reported, so that it is immediately known that an accident occurred due to an erroneous connection of an AC power supply or the like to the telephone line. By specifying the inspection location immediately, countermeasures after the accident can be easily taken.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a circuit block diagram showing a first embodiment of the telephone circuit of the present invention.

FIG. 3 is a circuit block diagram showing a second embodiment of the telephone circuit of the present invention.

FIG. 4 is a circuit block diagram of a conventional telephone circuit.

[Explanation of symbols]

 10: Receiver 12: Transmission path 14: Repeater for sensor 16: Analog smoke detector 18: Analog heat sensor 20: Repeater for control 22: Sensor line 24: On / off detector 25: Transmitter 26: Push button switch 28: Control line 30: Control load 32: Control CPU 34: Transmission input / output unit 36: Display unit 38: Telephone circuit unit 40, 48: Telephone 42: Telephone line (T line, TC line) 44, 56: Jack Terminal 46: Plug 50: Line abnormality detection unit 52: Receiver power supply 54: Receiver circuit unit 58, 60: Fuse resistance 64: Comparator 66: Fuse disconnection notification unit 68, 70: Fuse

Claims (4)

(57) [Claims] A receiver connected to a telephone circuit (42) receiving a DC bias from a receiver power supply (52) common to a receiving circuit unit (54) for receiving a detection information from a terminal and monitoring a fire. In the telephone circuit of the disaster prevention monitoring device for making a call between the telephone set (40) and the terminal telephone set (48), the receiver telephone set (T) is connected to the positive line (T) of the telephone line (42). One end of the telephone terminal (56) of the telephone line (4) is connected via a first capacitor (C1) for AC coupling and a diode (D2) for a reverse current element, and the telephone line (4) is connected.
2) Connect the telephone terminal (5) to the negative line (TC).
The other end of 6) is connected via a second capacitor (C2) for AC coupling, and when a voltage of a reverse polarity is applied to the telephone line (42) with the minus line being positive, the second capacitor (C2) is connected. C2) A bypass circuit for passing a current through the primary side and the secondary side of the telephone line (42) to the plus line (T) of the telephone line (42) is provided. A telephone circuit for a disaster prevention monitoring device, comprising a fuse means. 2. The telephone circuit of the disaster prevention monitoring device according to claim 1, further comprising: a receiver power supply (5) via a high resistance (R3).
A line abnormality detector (50) for monitoring the voltage of the negative line (TC) of the telephone line (42) connected to 2) and detecting and outputting a line abnormality when the voltage rises to a predetermined value or more; Fuse disconnection notifying means (6) for notifying the disconnection of the fuse means when the detection output of the detecting section (50) is obtained.
6). A telephone circuit of the disaster prevention monitoring device, wherein 3. A telephone circuit for a disaster prevention monitoring device according to claim 1, wherein said fuse means includes a fuse resistor (58,
60) A telephone circuit of a disaster prevention monitoring device, wherein the telephone circuit is used. 4. A telephone circuit according to claim 1, wherein said fuse means comprises a fuse (68, 7).
0) and a series circuit of resistors (R7, R8).