JPS61219254A - Subscriber's line disconnection automatic information device - Google Patents

Abstract

PURPOSE:To detect a line disconnection and automatically inform the line disconnection without adding a device to a subscriber's house by providing an alternating current bridge circuit making a side a subscriber's loop connecting side connected through a change-over circuit. CONSTITUTION:When a receiving is obtained, an inter-ringing signal comes to an exchanger connecting terminal 1, the receiving is detected in a receiving detecting circuit 6 and this detected output is inputted to a change-over drive circuit 8. A change- over circuit 5 is changed over and the exchanger connecting terminal 1 and the subscriber's loop connecting terminal 2 are connected by the change-over circuit 5. On calling, when the subscriber raised up the receiver, the loop is formed through the subscriber's loop connecting terminal 2, so that a change of an alternating current bridge circuit 9 is detected in a calling detecting circuit 11, and the subscriber's loop connecting terminal 2 is connected to the exchanger connecting terminal 1. When the disconnection is generated, impedance in the alternating current bridge circuit 9 is changed, so that the change is detected by a disconnection detecting circuit 12 and the detected signal is transmitted to an automatic informing circuit 3, and a disconnection detecting data is informed automatically to an external guarding center or the like.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention connects to a subscriber's line and prevents disconnection of the subscriber's line regardless of whether the subscriber's telephone is in use or not. The present invention relates to an automatic subscriber line disconnection notification device that detects a disconnection of a subscriber line and outputs the disconnection detection data to an automatic notification circuit to automatically notify a security center or the like.

[Prior art]

In recent years, systems such as emergency call devices that are installed in subscriber's homes and that automatically dial a pre-designated security center or the like in the event of an emergency have become widespread.

By the way, in such a system, mutual communication is performed at fixed times in order to confirm the normality of the subscriber line between the subscriber's house and the security center, but the subscriber line is disconnected before the next mutual communication. There was a drawback that if the line was disconnected, alarms could not be issued via communication.

As a countermeasure against this, there is a method of installing a transmitter in the home and constantly sending out monitoring signals, but this method involves installing a filter in addition to the transmitter in the home to prevent the monitoring signal from affecting calls. It is necessary to install it.

Another method is to connect two lines to a subscriber's home, and when one of them is disconnected, the normal line sends a disconnection alarm to the security center, but this also becomes invalid if the lines are disconnected at the same time, and the You have to invest in equipment.

[Purpose of the invention]

The present invention was made in view of the above, and its purpose is to add a device to a subscriber's home by connecting it to both sides of the subscriber's line exchange (while the telephone is in use or not). We have developed an automatic subscriber line disconnection reporting device that can detect line disconnections regardless of whether the line is disconnected, automatically report the disconnection to a security center, etc., and improve the reliability of the security system. It is to provide.

[Structure of the invention]

For this purpose, the subscriber line disconnection automatic notification device of the present invention detects an incoming call signal arriving from the switching circuit connected between the exchange connection terminal and the subscriber line connection terminal and the exchange connection terminal side. an incoming call detection circuit that switches the switching circuit according to the output to connect the exchange connection terminal and the subscriber line connection terminal, and detects this by forming a loop in the line on the subscriber line connection terminal side; a call detection circuit that switches the switching circuit to connect the exchange connection terminal and the subscriber line connection terminal; and the switching circuit in a state where the exchange connection terminal and the subscriber line connection terminal are disconnected. an AC bridge circuit in which one side of the bridge is the subscriber line connection terminal side connected through the AC bridge circuit; and a disconnection detection circuit that receives the output of the AC bridge circuit and outputs a disconnection detection signal based on a change in the impedance of the bridge circuit. , and an automatic notification circuit that inputs the disconnection detection signal from the disconnection detection circuit and notifies a security center or the like.

〔Example〕

Examples of the present invention will be described below. FIG. 1 is a block diagram of an automatic subscriber line disconnection notification device showing one embodiment thereof. 1 is an exchange connection terminal, 2 is a subscriber line connection terminal, and between both terminals 1 and 2 is a call detection circuit 4 having reed relays 4a and 4b, and a transmission line A.
, B is connected between the terminals 1.2 and has contacts 5a, 5b.

Reference numeral 6 denotes an incoming call detection circuit for detecting incoming calls from the exchange side, and is connected to the transmission lines A and B via an incoming call input circuit 7 having contacts 7a and 7b.

Reference numeral 9 designates an AC bridge circuit that mainly detects disconnection on the subscriber line side when the telephone is not in use by impedance change. For example, 25H between 10 and 100Hz oscillated by the oscillation circuit 10 is formed by the circuit on the user line side, and as its power supply.
A frequency signal of z is input.

11 is a call detection circuit that detects whether the handset of a telephone on the subscriber line side has been lifted; 12 is a disconnection detection circuit that detects disconnection of the subscriber line when the telephone is not in use; The disconnection signal is input via the switching circuit 5 and the AC bridging circuit 9.

Reference numeral 3 denotes an automatic notification circuit for automatically reporting disconnection detection data to the security center based on the detection signal from the disconnection detection circuit 12.

Reference numeral 8 denotes a switching drive circuit, which inputs the incoming call detection output from the incoming call detection circuit 6 or the call detection output from the outgoing call detection circuit 11 to connect the contacts 5a and 5b of the switching circuit 5, as indicated by broken lines in the figure. After outputting a signal for switching from the side to the side shown by the solid line, when the call detection circuit 4 performs call detection (loop current detection), self-maintenance is achieved by the detection output.

When the call detection circuit 4 detects a call, the incoming call input circuit 7
A signal is also sent to the contact points 7a and 7b to switch them from the side shown by the solid line to the side shown by the broken line in the figure.

Next, the operation will be explained.

In this device, an exchange is directly connected to the exchange connection terminal 1 side, and a subscriber line is connected to the subscriber line connection terminal 2 side.

First, when there is no incoming call and the telephone connected to the terminal on the subscriber line side is not in use, the contacts 5a and 5b of the switching circuit 5
has switched to the side shown by the broken line in the figure, and the transmission line A
, B are separated between the exchange side and the subscriber line side. At this time, the contacts 7a and 7b of the incoming call input circuit 7 are switched to the solid line side.

When an incoming call is received in this state, an ink ringing (IR) signal arrives at the exchange connection terminal 1, and when this signal is input to the incoming call detection circuit 6 via the incoming call input circuit 7, the incoming call is detected in the incoming call detection circuit 6. The detection output is input to the switching drive circuit 8.

Therefore, the switching circuit 5 is switched by the switching drive circuit 8, and its contacts 5a and 5b are switched to the side shown by the solid line in the figure. Therefore, the exchange connection terminal 1 and the subscriber line connection terminal 2 are connected by the switching circuit 5, and the interringing signal is transmitted to the subscriber's telephone to ring the bell.

Then, when the subscriber lifts up the handset, a loop is formed and a loop current flows, so the call detection circuit 4 detects this, and its detection output is input to the switching drive circuit 8, which then switches to the switching drive circuit 8. The switching state of the switching circuit 5 is maintained. In addition, contacts 7a and 7b of the incoming call input circuit 7
is switched to the broken line side by the detection output from the call detection circuit 4.

On the other hand, when a call is made from the subscriber line side to which this device is connected, when the subscriber lifts up the handset, a loop is formed through the subscriber line connection terminal 2, so changes in the AC bridge circuit 9 are detected by the call detection circuit. 11, and its detection output is input to the switching drive circuit 8. Therefore, the switching circuit 4 is switched in the same manner as described above, and the subscriber line connection terminal 2 is connected to the exchange connection terminal 1. Therefore, the call detection circuit 4
detects this, and similarly to the above, the switching drive circuit 8 self-maintains and the switching state of the switching circuit 5 is maintained.

When the subscriber has finished using the telephone, the subscriber hangs up the telephone.
Since the loop on the subscriber line side is opened, the call detection circuit 4 detects this, releases the self-holding of the switching drive circuit 8, and returns the contacts 5a and 5b of the switching circuit 5 to the side shown by the broken line. .

Disconnection detection is performed as follows.

Detection of disconnection on the subscriber line side is performed by an AC bridging circuit 9 and a disconnection detection circuit 12. That is, when a wire breakage occurs, the impedance of the AC bridge circuit 9 that uses a 25 Hz frequency source as a power source changes, so the change is detected by the wire breakage detection circuit 12, and the detection signal is sent to the automatic notification circuit 3. Disconnection detection data is automatically reported to external security centers, etc.

FIG. 2 is a specific circuit diagram of the AC bridge circuit 9 and its surrounding circuit parts. The AC bridge circuit 9 has a resistor R1
, R2, a series circuit of capacitor C1 and variable resistor VRI,
Each bridge forming side is constituted by a subscriber line connected between terminals 9a and 9b. 9c and 9d are AC power supply terminals, and 9e and 9f are output terminals. Further, the resistor R3 and the power source E are used to supply current when a call is detected. Further, the resistor R4 and the variable resistor VR2 constitute a power input part from the oscillation circuit 10, and the variable resistor VR2 also constitutes a shunt part to the call detection circuit 11.

The call detection circuit 11 has an input resistor R5 and a protection diode D.
1 and a transistor Q1, and the conduction output of the transistor Q1 is transmitted to the switching drive circuit 8 via, for example, a relay.

The disconnection detection circuit 12 is composed of a transformer 12a and an amplifier 12b, and the input side of the transformer 12a is connected to output terminals 9e and 9f of the AC bridge circuit 9.

The oscillation circuit 10 is connected to terminals 9c and 9d of the bridge circuit 9 via a resistor R4 and a variable resistor VR2.

In FIG. 2, when the subscriber lifts the handset, conduction occurs between terminals 9a and 9b of AC bridge circuit 9, so that current from power source E flows from resistor R3 to terminal 9C to resistor R1 to terminal 9e to Terminal 9a - subscriber line - telephone - terminal 9b = terminal 9d - resistor R4 - input to call detection circuit 11 via variable resistor VR2, transistor Q1 conducts,
Call detection is performed.

In addition, in the AC bridge circuit 9, when the subscriber line is disconnected when the telephone on the subscriber line side is not in use, the impedance between the terminals 9a and 9b changes, so the impedance of the bridge changes, and the change component is the output terminal 9e. , between 9f,
In other words, it appears on the input side of the transformer 12a. This signal is a disconnection signal, and is sent to the automatic notification circuit 3 after being amplified by the amplifier 12b.

In addition, if the line is disconnected while the telephone is in use, the contacts 5a and 5b of the switching circuit 5 return to the broken line side, so the disconnected state is detected by the AC bridge circuit 9 in the same way as above, and the disconnection detection circuit 12, the disconnection detection signal is sent to the automatic notification circuit 3.

〔Effect of the invention〕

As described above, according to the present invention, disconnection on the subscriber's line side can be detected whether the telephone is in use or not in use, without adding any equipment to the subscriber's equipment. , the disconnection can be automatically reported to the security center, etc., and intentional disconnection of the subscriber's line by an external intruder can be immediately detected, greatly contributing to improving the reliability of the security system. It is something to do.

[Brief explanation of drawings]

FIG. 1 is a circuit block diagram of an automatic subscriber line disconnection notification device according to an embodiment of the present invention, and FIG. 2 is a specific circuit diagram of a disconnection detection portion. DESCRIPTION OF SYMBOLS 1... Exchange connection terminal, 2... Subscriber line connection terminal, 3... Automatic notification circuit, 4... Call detection circuit, 5.
... Switching circuit, 6... Incoming call detection circuit, 7... Incoming call input circuit, 8... Switching drive circuit, 9... AC bridge circuit, 10... Oscillation circuit, 11... Call origination detection circuit,
12...Disconnection detection circuit.

Claims (1)

[Claims] (1) A switching circuit connected between an exchange connection terminal and a subscriber line connection terminal, detects an incoming signal coming from the exchange connection terminal side, switches the switching circuit according to the detection output, and connects the exchange to the exchange. An incoming call detection circuit connects the terminal and the subscriber line connection terminal, and detects when a loop is formed in the line on the subscriber line connection terminal side, and switches the switching circuit to connect the line to the exchange connection terminal. a call detection circuit that connects the subscriber line connection terminals; and the subscriber line connection that connects the subscriber line connection terminals through the switching circuit in a state where the exchange connection terminals and the subscriber line connection terminals are disconnected. an AC bridge circuit in which the terminal side is one side of the bridge; a disconnection detection circuit that receives the output of the AC bridge circuit and outputs a disconnection detection signal by changing the impedance of the bridge circuit; An automatic notification device for subscriber line disconnection, comprising an automatic notification circuit for inputting information and notifying a security center, etc.