JPH0714179B2 - Telephone line disconnection notification device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a telephone line disconnection notification device for monitoring and notifying a disconnection of a connected telephone line.

[Prior Art] Conventionally, it is constantly monitored whether or not a disconnection occurs in a telephone line from a telephone exchange to a subscriber's telephone,
There is no device that outputs an alarm to a subscriber when a disconnection occurs.

[Problems to be solved by the invention] Therefore, even if the telephone line is broken, there is no means to immediately know it, and only after raising the handset of the telephone and checking the dial tone from the central office, It was noticeable abnormally. Moreover, is it a malfunction of the telephone,
I didn't know if the line was broken.

Further, in recent years, in many cases, such as an internal guerrilla incident or a thief intruding into a house, the telephone line is cut off in advance so that it is not reported to the outside.

The present invention has been made to solve the above problems,
An object of the present invention is to provide a telephone line disconnection notification device capable of directly reporting a disconnection due to disconnection of a telephone line as a disconnection of a telephone line.

[Means for Solving the Problems] In order to achieve the above object, the telephone line disconnection notification device according to the present invention has the following configuration.

That is, detection means for detecting a lockout tone from the connected telephone line, monitoring means for monitoring whether or not the voltage value of the telephone line is within a predetermined range, and voltage value monitored by the monitoring means are predetermined. If the lockout tone is not detected within the range, a notification means for notifying the disconnection of the telephone line is provided.

[Operation] In the above configuration, the lockout tone from the connected telephone line is detected, the voltage value of the telephone line is monitored, and if the voltage value is within the predetermined range and the lockout tone is not detected, the line is disconnected. It operates so as to notify that effect.

[Embodiment] A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

<Description of Configuration (FIG. 1)> FIG. 1 is a schematic block diagram of the telephone line disconnection notification device 1 according to the present embodiment, and details thereof will be described later with a monitoring unit 10 and a notification unit 2.
0, a rosette 30, and a detector 40. As shown in the figure, the telephone line disconnection notification device 1 is connected to the telephone lines L1 and L2 between the exchange 2 and the telephone 3 of the central office, and the telephone line L1 is monitored by monitoring the voltage values of the telephone lines L1 and L2. , Disconnection of L2 or the like is notified.

When the exchange 2 detects the off-hook of the telephone 3 for a long time (20 seconds), the telephone 3 receives a lockout tone (400H).
Since the telephone 3 is disconnected from the control unit after sending z), the voltage between the telephone lines L1 and L2 becomes almost "0". Therefore, the detection unit 40 of the present embodiment detects the lockout tone (400 Hz) and outputs the alarm output prohibition signal 41 to the notification unit 20 for a predetermined time so that the telephone line is in the normal state "0". "I try not to report the voltage as a disconnection.

Further, in the notification unit 20, the on / off output input from the monitoring unit 10 described later is on (the voltage value of the telephone lines L1 and L2 is “0”)
Even so, the alarm output prohibition signal 41 from the above-mentioned detection unit 40
If is output, it operates so as not to notify the disconnection.

The detection unit 40 in this embodiment is composed of a frequency detection circuit (not shown), and the notification unit 20 is a known circuit composed of a speaker, a logic circuit, etc. (not shown), and a description thereof will be omitted.

<Description of Monitoring Unit (FIGS. 2 and 3)> Next, an example of the monitoring unit 10 in the present embodiment will be described below with reference to FIGS. 2 and 3.

Incidentally, the monitoring unit 10 in the present embodiment monitors all voltage values such as an idle state of the telephone line and a call state, and if the voltage value is an abnormal voltage value due to a disconnection of the telephone line or the like, it notifies the notification unit 20. Output an ON signal. On the other hand, the notification unit 20 sounds the buzzer by the output from the monitoring unit 10 to notify the disconnection.

FIG. 2 is a diagram showing a configuration of a window comparator circuit including a relay drive circuit.

First, focusing on only the comparator 16 of the window comparator circuit in FIG. 2, an outline of the input voltage and the operation of the relay (Ry) will be described.

Telephone line L1, the voltage of L2 V _IN, the reference voltage set by the resistor 12 V _REF, and the output of comparator 16 and V _OUT, V _IN
V _OUT when ≧ V _REF is turned on, when V _IN <V _REF V _OUT
Turns off. When the V _OUT is turned on, the relay (Ry) is driven, and the on / off signal to the notification unit 20 is output by this relay. When combined with the arithmetic circuit of FIG. 2 and the voltage set by the resistor 14 is V _W , V _IN ≧ V _REF
The relay turns on, and it operates so that V _IN = V _REF + V _W turns it off. That is, the resistor 14 determines the operating region width of the relay.

Therefore, by monitoring the voltage of the telephone lines L1 and L2 by the window comparator circuit shown in FIG. 2, the relay is driven when the voltage falls within the voltage range set in advance by the resistors 12 and 14, and the alarm unit ON signal is output to 20.

Next, the voltage value corresponding to each usage state of the telephone lines L1 and L2 and the operation relationship of the relay will be described below with reference to FIG.

It is known that the voltage value of the normal telephone lines L1 and L2 in the idle state is 48V, and that it decreases to about 4V to 20V due to the impedance of the telephone 3 in the talking state.

In this embodiment, as shown in FIG. 3, if the telephone line is idle, the voltage value is 48V and the output signal at that time is off. After that, when the call state is entered due to an incoming call to the telephone set 3 or the like, the voltage value changes to the range of 4V to 20V, but the output signal remains off. However, if the telephone lines L1 and L2 are disconnected at the same time with metal scissors, the telephone line L
Due to the short circuit between 1 and L2, the voltage value directly drops below 3V, and the output signal turns on for that voltage value.

Here, if a lockout tone (400 Hz) from the telephone line is not detected by the above-mentioned detection unit 40, the line is notified as a disconnection, but if it is detected, the disconnection tone is not notified.

As described above, according to this embodiment, by monitoring the lockout tone and the voltage value from the telephone line, the disconnection can be reliably notified with a simple configuration.

<Modification> If either one of the telephone lines L1 and L2 is disconnected,
In order to prevent the voltage monitoring circuit from affecting the characteristics of the telephone line because the capacitor connected to the rosette 30 or the telephone 3 remains charged to 48V, the telephone line should be connected to the telephone line with impedance as high as 5 MΩ to 10 MΩ or higher. Since they are connected, it takes several tens of seconds for the voltage of L1 and L2 to reach 0V.

Therefore, as shown in FIG. 3, when it is detected that the voltage values of L1 and L2 gradually decrease and become 47 V or less after 1 to 2 seconds,
It is also possible to configure the relay output to be turned on.

In the present embodiment, the buzzer is used as the notification unit 20 that inputs the ON / OFF signal output from the monitoring unit 10 and notifies the ON signal, but a notification device such as a speaker may be used.

FIG. 4 is a diagram showing a configuration of a monitoring unit that monitors an AC signal. As shown in the figure, output means for outputting an alternating current signal to the telephone line to be connected, monitoring means for monitoring the alternating current signal received from the telephone line, and the monitored alternating current signal in the monitoring means should be outside the predetermined alternating current signal range. For example, a telephone line disconnection is provided, and a notification means for notifying that is provided (specifically, an inaudible band signal (for example, an 18 KHz AC signal), a band pass filter (BPF), and a level meter (LM). It is also possible to monitor the AC signal from the telephone line and notify the disconnection by the configuration of “provide”.

As described above, according to the present invention, the voltage value from the telephone line is monitored, and if the lockout tone is not detected within the predetermined voltage value range, the telephone line is directly connected. Can be notified as a disconnection due to disconnection or the like.

[Brief description of drawings]

FIG. 1 is a block diagram of a telephone line disconnection notification device according to an embodiment of the present invention, FIG. 2 is a circuit diagram of the monitoring unit 10 of FIG. 1, and FIG. 3 is a diagram for explaining the operation relationship of FIG. FIG. 4 is a block diagram of another configuration of the monitoring unit 10. In the figure, 1 ... Telephone line disconnection notification device, 2 ... Switch, 3 ...
... phone, 10 ... monitoring section, 20 ... informing section, 30 ... rosette, 40 ... detection section.

Continuation of the front page (56) Reference JP-A-60-196052 (JP, A) JP-A-50-93520 (JP, A) JP-A-51-25908 (JP, A) JP-A-59-57555 (JP , A) JP-B 43-28536 (JP, B1) JP-B 43-29174 (JP, B1) JP-B 44-96 (JP, Y1) JP-B 43-29626 (JP, Y1)

Claims (1)

[Claims] 1. A detection means for detecting a lockout tone from a connected telephone line, a monitoring means for monitoring whether or not the voltage value of the telephone line is within a predetermined range, and a voltage value monitored by the monitoring means. Is within a predetermined range and the lockout tone is not detected, the telephone line disconnection informing device is provided with an informing means for informing that fact as a disconnection of the telephone line.