JPH0317500Y2 - - Google Patents

Description

[Detailed description of the invention] (Industrial field of application) The present invention relates to a busy confirmation device for a subscriber telephone line, which uses a searching knife or the like to connect multi-pair cable core wires as the subscriber line status confirmation means. be.

(Problems to be solved by conventional technology and invention) In the conventional busy confirmation device, for example, the first
A line test transceiver with the circuit configuration shown in Figure 2 or Figure 2 was used.

In the busy confirmation device shown in FIG. 1, subscriber lines L ₁ and L ₂ of a central telephone office are connected to a transmitter T or a receiver R via switches SW ₁ and SW ₂ .

Further, in the busy confirmation device shown in FIG. 2, the subscriber lines L ₁ and L ₂ of the telephone office are connected to the transmitter T or the receiver R via a capacitor or the like.

The capacitor cuts off the direct current part of the communication current, stops the operation of the transmitter, and allows only the receiver to be monitored, and is used to prevent interrupt calls.

However, in the equipment shown in Figure 1, the MDF inside the telephone office
Unlike testing using terminals such as (main distribution board), tests are mainly performed at cable connection points such as outdoor manholes, so the subscriber line
Since it is necessary to search for the two lines L ₁ and L ₂ and bring the probe knife into contact with them to establish continuity, there is an inconvenience that the work efficiency becomes poor.

On the other hand, in the device shown in Figure 2, a current of 15 mA or more is shunted from the subscriber's line to the ground via the handset and receiver, and the volume between the subscriber lines decreases, causing noise such as clicking noise and grounding noise. I was afraid.

In addition, with these busy confirmation devices, even if the subscriber's line is busy, if the subscriber is not talking, the subscriber's line is incorrectly determined to be unused, and the subscriber dials while being monitored. There was an inconvenience that I was unable to connect to the other party even if I searched for it.

For this reason, these busy confirmation devices misidentify a used line as an unused line, and when performing cable switching work, the volume between subscriber lines decreases, causing clicking sounds, grounding sounds, etc. This caused noise and caused complaints from telephone subscribers.

Therefore, the present invention uses a voltage divider to divide the input voltage when a search knife is brought into contact with the multi-pair cable core wire, thereby preventing the volume between subscriber lines from decreasing, and preventing clicking noise and grounding. It is an object of the present invention to provide a busy confirmation device for a subscriber telephone line that prevents noise such as sound from entering the subscriber line.

(Means for Solving the Problems) As a means for solving the above problems, the present invention provides
In a busy confirmation device equipped with means for displaying subscriber line status including busy status, a search knife 4 conducts the subscriber line status confirmation means to a multi-pair cable core wire.
and a voltage divider 6 that divides the voltage between the subscriber line and the ground into minute voltages when the multi-pair cable core wire is brought into contact with the search knife, and amplifies the voltage based on the voltage divider output of this voltage divider 6. an amplifier section 7; a comparator 8 which obtains a comparison output from the difference between the output voltage of the amplifier section 7 and a corresponding reference voltage corresponding to the subscriber line state including the busy state; and a comparison output from the comparator 8. The system is comprised of a control section 9 which obtains a control output based on the control section 9, and display sections 10 and 11 which display the state of the subscriber's line, including busy state, based on the output of the control section 9.

(Function) In this subscriber line status confirmation means, first, the search knife 4 is used to pierce the multi-pair cable core wire to establish contact continuity.

Then, the voltage when the multi-pair cable core wire is brought into contact with the search knife 4 is divided into minute voltages by the voltage divider 6.

In other words, it is possible to reduce the current value at which the line current is shunted through the search knife, thereby preventing a decrease in the volume of the subscriber's line and the mixing of clicking sounds and ground sounds caused by insertion of the search knife.

Based on the voltage divider output of this voltage divider 6, the amplifier 7
amplify it to the required voltage.

In the voltage divider 6, the input voltage (voltage between the subscriber's line and the ground) that has been brought into contact conduction by the search knife 4 is divided into minute voltages, thereby reducing the shunt value from the subscriber's line, causing clicking noises and grounding noises. To enable a search without reducing the volume between subscriber lines while preventing noise such as noise from entering the subscriber lines.

Next, a comparator 8 obtains a comparison output from the difference between the corresponding reference voltage corresponding to the subscriber line state such as busy and the output voltage of the amplifying section 7.

Then, based on the comparison output from the comparator 8, the control section 9 obtains a control output.

The output of the control section 9 causes the busy display sections 10 and 11 to display that the subscriber line is busy, including when there is no sound, or that the subscriber's line is dialing.

(Example) Next, an example of the present invention will be specifically described based on the drawings.

FIG. 3 is a perspective view showing the overall configuration of one embodiment of the busy confirmation device of the present invention, and FIG. 4 is a system block diagram showing an embodiment of the busy busy confirmation device of the present invention.

In these figures, reference numeral 1 denotes a search device, and a search knife 4 is attached to the side of the search device 1 so that it can be freely drawn out and stored.

The search knife 4 is a multi-pair cable (100 to 7200
This method is suitable for searching for books), and the searching knife 4 is thrust into the core wires to establish contact and conduction without peeling off the coating of each core wire.

In other words, in this embodiment, since it is possible to search without removing the covering of each core wire, it is possible to reduce the introduction of various noises, and because the noise between subscriber lines is reduced, it is possible to conduct a call between subscriber lines. You can prevent it from getting in the way.

Furthermore, in this embodiment, the searcher 1 determines whether the subscriber's line is dialing, busy, or unused, and if the subscriber line is dialing or busy, the light flashes or turns off, and if it is unused, the light turns on. GO indicator lamp 10, which lights up when in the "feeding" state, that is, when power is being supplied to the line from the central office.
Micro switch 14 for display lamp and busy confirmation
It is equipped with

The busy confirmation device of this embodiment is always in a standby state regardless of whether the busy confirmation micro switch 14 is on or off.

Further, in this embodiment, the search device 1 and the busy confirmation device main body 2 are connected by a connection cord 3.

The busy confirmation device main body 2 includes a voltage divider 6, an amplifier 7,
It consists of a comparator 8, a control section 9, a busy alarm buzzer 12, an internal voltage display lamp 16, and other subscriber line status confirmation means.

Next, the subscriber line status confirmation means will be explained in detail based on the main circuit diagram of FIG. 5.

This subscriber line status confirmation means has a grounding terminal E1 and a search knife 4, and the grounding terminal E1 is connected to the shield part of the cable covering when working inside a manhole, and to the MDF (main distribution frame) when working within a station. Make sure to connect it vertically and firmly to the ground terminal. By connecting the search knife 4 to the subscriber line _L1 or _L2 , the voltage of the subscriber line appears between E1 and N1, and R1 suppresses the communication current flowing to the ground side as much as possible. Voltage divider 6 is constituted by R1 and variable resistor R5, and the input voltage divided here is applied to amplifier 7, where it is amplified to a reference voltage level and applied to comparator 8. When a partial voltage corresponding to 48V of the subscriber line voltage (when not in use) is input to the comparator 8, it is output to D1 and D5, and then passed through the control unit 9 to a switching GO indicator lamp 10 consisting of an LED. The feeding power indicator lamp 11 is turned on and the operation of the alarm buzzer 12 is stopped.

Next, correspond to when the subscriber line is in use or on standby.
When a partial voltage corresponding to a range of 6.8 V or more is detected as input, only D1 is output, the power indicator lamp 11 is turned on via the control section 9, and the alarm buzzer 12 is activated. At this time, the switching GO indicator lamp 10 does not light up because there is no D5 output from the comparator 8, and it is possible to confirm and detect that the call is busy. Also, during dialing, the DC loop circuit between the exchange and the telephone is intermittent, so the line voltage when not in use
Since 48V and OV are output alternately, the switching GO display lamp 10 blinks and the alarm buzzer 12 sounds, so it can be detected that switching work cannot be performed, just like when a call is in progress.

In addition, in FIG. 5, R17 to R19,
SW1-2, Q5, LED3, etc. constitute a power supply circuit.

As mentioned above, the voltage divider 6 is constituted by R1 and the variable resistor R5, and is specifically set to a high resistance of 170KΩ or more. This makes it possible to extremely reduce the communication current that flows through the search knife 4 from the subscriber lines L ₁ and L ₂ to the ground.

In this voltage divider 6, the input voltage (voltage between the subscriber's line and the ground) that has been brought into contact with the search knife 4 is divided into minute voltages, and the call current is divided from the subscriber's line to the main body 2 of the busy confirmation device. Since it can be made extremely small, it is possible to prevent noises such as click sounds and ground sounds that occur when the search knife 4 is inserted into the line from entering the subscriber line. Furthermore, even if the call current is divided through the high-resistance voltage divider 6, the value of the shunt current is extremely small and the call current hardly decreases, so it is possible to search without reducing the volume between subscriber lines. It becomes possible.

Therefore, by using the voltage divider 6, the influence on the subscriber line can be reduced, so even if the search knife 4 is inserted into the core line while the subscriber line is in use, it will not be possible to detect a busy subscriber line. It is possible to prevent noise from causing discomfort to the user.

In the amplifier 7, the output from the voltage divider 6 is amplified to a required voltage.

That is, the voltage divider 6 is connected to the input terminal of the amplifier 7.
Since the minute voltage divided by is inputted, it is possible to prevent noises such as clicking sounds and ground sounds from being inputted to the amplifying section 7.

Then, in the comparator 8, a comparison output is obtained from the difference between the corresponding reference voltage and the output voltage of the amplification section 7.

The corresponding reference voltage inputted to the comparator 8 is the reference voltage corresponding to the dialing, busy, and unused states.

Normally, the voltage supplied from the exchange is -48V between _L2 and E at the _L1 grounding station, so for example, when dialing or busy, in standby with no sound, or when busy, -8 to - Set each reference voltage in the 40V range, or -48V when not in use (the positive and negative signs will be reversed if it is an L ₂ grounding station), and compare these with the divided detection voltage. What is necessary is to make the determination without any errors. of course,
Since the detected power differs depending on the search position and the distance from the exchange, the reference voltage is also set taking into account the voltage drop. Similarly, it is also adjusted by the amplification degree of the detection voltage.

The control unit 9 is composed of an exclusive OR circuit,
An EX-OR output is obtained based on the comparison output of the comparator 8 and the corresponding reference voltage.

In this embodiment, busy confirmation units 10 to 12 perform confirmation based on the EX-OR output of control unit 9.

In this embodiment, for example, during dialing or talking, the display lamp of the busy confirmation section 11 lights up or flashes, and the buzzer of the busy confirmation section 12 sounds.

Further, when the subscriber line is not in use, the lamps of the busy confirmation units 10 and 11 only emit light.

Further, when the subscriber line is idle, the lamps and buzzers of the busy confirmation units 10 to 12 do not operate.

In addition, in this embodiment, in consideration of long-term use, an external power supply DC input jack 13 is provided on the main body 2 so that 100V from the engine generator or commercial power supply can be used, and a commercially available AC adapter is used. ,
It may also be used as a power source for the verification device of this invention.

In this case, the confirmation device is always on standby regardless of the busy confirmation microswitch 14, and can perform busy confirmation work quickly and continuously for a long time.

The main body 2 is also provided with an internal battery voltage check button switch 15 and an internal battery voltage display lamp 16.

In this example, the voltage between the subscriber's line and the ground is divided as described above, and the input voltage is amplified to the reference voltage by focusing on the fact that the voltage when dialing or busy is different from that when not in use. By comparing this with preset corresponding reference voltages for dialing, busy, and non-use, it is possible to check the usage status of the subscriber line.

Therefore, in this embodiment, the input voltage taken in is amplified to a reference voltage, and this is compared with the corresponding reference voltage set in advance for dialing, busy, and not in use. dialing, busy, etc. without mistaking the line as unused.
It is possible to correspond to when the subscriber line is not in use and to select the switching timing of the subscriber line reliably.

Further, in this embodiment, even when using the subscriber's line, it is possible to prevent the influence of noise and the like from occurring.

(Effects of the invention) As described above, according to the invention, the voltage between the subscriber's line and the ground is divided, the input voltage that is input after the voltage division is amplified to a reference voltage, and this is applied to a preset dial. By comparing the reference voltage with the corresponding reference voltage during a busy call, including when there is no sound, it is possible to prevent a subscriber's line in use from being mistakenly recognized as unused.
To respond to calls during calls, including silent times, and to reliably select the timing for switching subscriber lines.

In particular, with this invention, the divided voltage from the subscriber's line becomes a minute voltage during the verification process, making it possible to extremely reduce the communication current flowing into the verification device, thereby eliminating noise such as clicking sounds and ground sounds during the search. This eliminates the problem of deterioration in call sound, which has the effect of preventing adverse effects on subscriber lines.

[Brief explanation of the drawing]

Figures 1 and 2 show a conventional busy confirmation device;
The figure is a perspective view showing the overall configuration of one embodiment of the busy confirmation device of the present invention, FIG. 4 is a system block diagram showing an embodiment of the busy busy confirmation device of the present invention, and FIG. 5 is an embodiment of the present invention. FIG. In the figure, 4 is a search knife, 6 is a voltage divider, 7 is an amplifier, 8 is a comparator, and 10 to 11 are indicator lamps (display section).

Claims (1)

[Scope of utility model registration request] In a busy confirmation device comprising means for displaying a subscriber line status including busy based on an input voltage when the subscriber line is contacted, a search knife for conducting the subscriber line status confirmation means to a multi-pair cable core wire. 4
and a voltage divider 6 that divides the voltage between the subscriber line and the ground into minute voltages when the multi-pair cable core wire is brought into contact with the search knife, and amplifies the voltage based on the voltage divider output of this voltage divider 6. an amplifier section 7; a comparator 8 which obtains a comparison output from the difference between the output voltage of the amplifier section 7 and a corresponding reference voltage corresponding to the subscriber line state including the busy state; and a comparison output from the comparator 8. A control section 9 that obtains a control output based on the control section 9, and display sections 10 and 11 that display the state of the subscriber line, including busy state, based on the output of the control section 9. Medium confirmation device.