JPH0832711A - Telephone terminal switching device - Google Patents

Abstract

PURPOSE:To automatically switch a line to a telephone set side through the off-hook operation of a telephone set in a modem unused state when a modem terminal machine wherein the telephone set is incorporated has one telephone line. CONSTITUTION:When one telephone line is available, it is connected to MJ1. The switch 4 is normally on an 'M' side and a communication through a modem 2 is possible. No telephone line is connected to MJ21, so the output of a line current detection part 24 is an L signal and inverted by an inverting circuit 26 into an H signal, which is inputted to an AND circuit 25. If the modem 2 is in communication, when the telephone set 3 is operated into the off-hook state, the line current detection part 6 outputs an H signal and the inverting circuit 27 inverts it into an L signal, so that the signal is inputted to the AND circuit together with the H signal from a hook detection part 7. The AND circuit inputs the H, L, and H signals, so the output is an L signal and a driving part 5 does not operate, so that the switch 4 is held on the M side. When the modem 2 is not used, the line current detection part 6 generates an L output and the inverting circuit 27 inverts it into an H signal, so the AND circuit generates an H output and the driving part 5 operates to switch the switch 4 to the T side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telephone terminal switching device for switching one telephone line between a modem and a telephone, and when the telephone line is off-hook, the telephone line is switched to the telephone side. Regarding things.

[0002]

2. Description of the Related Art A modem terminal having a built-in telephone and a modem for data communication is provided with a modular jack (line connection section) for the telephone and a modular jack for the modem, and two telephone lines are used. Some modems and telephones can be used independently. With this device, if there are two telephone lines that can be used, two modular cables can be connected to each modular jack, but if there is only one telephone line, the modular cable must be replaced. There is inconvenience.

[0003]

SUMMARY OF THE INVENTION In view of the above, the present invention provides a modem terminal having a built-in telephone, and when there are two telephone lines, the telephone line and the modem can be used simultaneously by the telephone line. If there is only one line, you can automatically switch to the telephone or modem without reconnecting the modular cable, and do not prevent communication by the modem when the telephone goes off-hook while using the modem. It is in.

[0004]

In order to solve the above-mentioned problems, the present invention uses one telephone line by switching between a telephone and a modem, in which a switch for switching a telephone line from a modular jack to a telephone or a modem is provided. , A drive unit that drives the switch, a detection unit that detects the line current of the modem and outputs a signal when the current value exceeds the required value, a hook detection unit that outputs a signal when the telephone is off-hook, and a signal from the detection unit and hook detection And a logic circuit that outputs a signal from the hook detection unit and outputs a signal when the detection unit does not output a signal, and switches the switch via the drive unit based on the signal from the logic circuit. A telephone terminal switching device for switching to a telephone side is provided.

[0005]

With the above construction, in the telephone terminal switching device according to the present invention, when two telephone lines can be used, the modem and the telephone are connected to different telephone lines, but one telephone line is used. In this case, by connecting the modular cable to the modem / telephone dual-purpose modular jack, the telephone line can be automatically switched to the modem or the telephone. However, even if the telephone is off-hook during communication by the modem, the communication is not hindered.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a telephone terminal switching device according to the present invention will be described in detail below with reference to the drawings. 1 is a connection diagram of essential parts of an embodiment of a telephone terminal switching device according to the present invention, and FIG. 2 is a connection diagram of essential parts of another embodiment.

In FIG. 1, reference numeral 1 is a modular jack that also serves as a modem / telephone, 2 is a modem, and 3 is a telephone. Four
Is a switch, which is driven by the driving unit 5 and switches the telephone line from the modular jack 1 to the modem 2 side or the telephone 3 side. Reference numeral 6 denotes a line current detection unit which detects that the telephone line of the modem 2 is being used based on the line current. Reference numeral 7 is a hook detection unit that detects off-hook of the telephone 3. Reference numeral 8 denotes a logic circuit, which outputs a signal to the drive unit 5 when the hook detection unit 7 detects the off-hook of the telephone 3 and when the line current detection unit 6 does not detect the current (the modem 2 is not used),
The switch 4 is switched to the telephone 3 side.

In FIG. 2, 21 is a modular jack dedicated to the telephone, 22 is a switch for connecting / disconnecting the telephone line from the modular jack 21 to / from the telephone 3, and 23 is a drive unit for driving the switch 22. 24 is a line current detector,
Detects the line current supplied from the modular jack 21. Reference numeral 25 denotes a logic circuit, which is used when the hook detector 7 detects an off-hook of the telephone 3, the current detector 24 does not detect the line current, and the line current detector 6 does not detect the current (the modem 2 is not used). A signal is output and the switch 4 is switched to the telephone 3 side via the drive unit 5, and at the same time, the switch 22 is switched to the non-connection via the drive unit 23. The other reference numerals are the same as those in FIG.

Next, the operation of the telephone terminal switching device according to the present invention will be described. In the case of FIG. 1, the telephone line from the modular jack 1 is normally connected to the modem 2, and the modem 2 is ready for communication at any time. The line current detector 6
For example, a direct current supplied from an exchange through a telephone line is constantly detected by a photocoupler, and when a current indicating the operation of the modem 2 is flowing, the light emitting diode in either the left or right direction emits light. The phototransistor is turned on by the light, a current flows from the power supply, and an "H" signal (power supply voltage) is output. This "H" signal is "L" by the inverting circuit 9.
The signal is inverted and applied to one terminal of the AND circuit 8.
When the telephone 3 is off-hook, the switch 7 is switched to the off-hook side (the lower switch is the power supply side) by this off-hook, and "H" (power supply voltage) is applied to the other terminal of the AND circuit 8. Therefore, the output of the AND circuit 8 becomes "L", and the base electrode of the NPN transistor 10 of the drive unit 5 connected to the output terminal is "L" (0V), so that the transistor 10 does not conduct and the relay 10 Since no current flows through 11, the switch 4 maintains the state switched to the modem side (M).

When the modem 2 is not used, since the line current does not flow in the modem 2, the line current detector 6 does not emit light, the phototransistor is non-conductive, and the output is "L". This "L" signal is inverted to "H" by the inverting circuit 9 and applied to the AND circuit 8, and the AND circuit 8 outputs "H" from the hook detection unit 7 when the telephone 3 is off-hook.
The signal outputs an "H" signal, which causes the transistor 10 of the drive unit 5 to conduct, the drive current to flow through the relay 11, the switch 4 is switched to the telephone side (T), and is connected to the modular jack 1. The existing telephone line is closed by the telephone 3, so that the telephone 3 can talk.

In the case of FIG. 2, when two telephone lines can be used, the modular cable of each line is modular jack 1
And modular jack 21 respectively. As a result, the modem 2 can independently communicate / talk with the telephone line connected to the modular jack 1 and the telephone 3 with the telephone line connected to the modular jack 21. That is, the switch 4 is switched to the modem side (M), and the off-hook of the modem 2 closes the telephone line with the exchange to enable communication. When the telephone 3 is off-hook, the "H" signal is output from the off-hook detection unit 7,
At the same time, an "H" signal is output from the line current detection unit 24 in this off-hook and inverted by the inversion circuit 26 to "L".
Become a signal. Since the AND circuit 25 adds the "H" signal and the "L" signal, it outputs the "L" signal regardless of the signal from the line current detecting section 6, and accordingly, the driving section 5
The transistor 10 and the transistor 28 of the drive unit 23 are not conductive, the switch 4 is kept switched to the modem side, and the switch 22 is kept connected.

When there is only one telephone line, this telephone line is connected to the modular jack 1 which also serves as a modem / telephone. Since the telephone line is not connected to the modular jack 21, the output signal of the current detector 24 is always "L", and this signal is inverted by the inverting circuit 26 to the "H" signal and applied to the AND circuit 25. To be done. When the telephone line of the modular jack 1 is used by the modem 2, the line current detector 6 outputs the "H" signal as in the above, and this signal is inverted by the inverting circuit 27 into the "L" signal and the logical product circuit. Join 25. Therefore, even if the "H" signal is output from the hook detection unit 7 when the telephone 3 is off-hook, the output signal of the AND circuit 25 is "L", the transistor 10 of the drive unit 5 is not conductive, and the switch 4 is turned on. The state switched to the modem side (M) is continued.

When the telephone line is not used by the modem 2 when the telephone 3 is off-hook, the AND circuit 25 receives the "H" signal from the hook detection unit 7 and the "L" signal from the line current detection unit 6. The "H" signal inverted by the inverting circuit 27 and the "H" signal from the inverting circuit 26 are applied at the same time, and the AND circuit 25 outputs the "H" signal. 10 is conducted, a current flows through the relay 11, the switch 4 is switched to the telephone side (T),
A telephone call by the telephone 3 becomes possible. At this time, the "H" signal is also applied to the drive unit 23, the transistor 28 becomes conductive, and the relay 29 is driven to switch the switch 22 to non-conductive, which is that the telephone 3 is connected to the modular jack 1. During a call on the telephone line, for example, the modular cable of another telephone line is connected to the modular jack 21, the telephone line of the modular jack 21 that was disconnected due to a failure, etc. is restored, or this telephone line is This is for switching use with the terminal device, so that when this device ends the call and the telephone line of the modular jack 21 becomes usable, the call of the telephone 3 is not disturbed. . The operation of the drive unit 5, the line current detection unit 6, the hook detection unit 7, the AND circuit 8, the inverting circuit 9, the drive unit 23, the line current detection unit 24, the AND circuit 25 and the inverting circuits 26, 27, etc. When the power required for the above cannot be obtained from the telephone line, a power supply unit may be provided in the apparatus and the power supply unit may supply power to each unit.

[0014]

As described above, according to the telephone terminal switching device of the present invention, the switching operation is not required when there are two telephone lines and when there is only one telephone line. If you have two lines, use these two lines as a modem /
By connecting to the modular jack that also functions as a telephone and the modular jack that is dedicated to the telephone, you can communicate / call with the modem and the telephone, respectively. If the modem is not used, you can make a call by hooking the phone off-hook, which is convenient because you do not need to connect and disconnect the modular cable.

[Brief description of drawings]

FIG. 1 is a connection diagram of essential parts of an embodiment of a telephone terminal switching device according to the present invention.

FIG. 2 is a main part connection diagram of another embodiment of the telephone terminal switching device according to the present invention.

[Explanation of symbols]

 1 Modular jack (combined with modem / telephone) 2 Modem 3 Telephone 4 Switch 5 Drive section 6 Line current detection section 7 Hook detection section 8 AND circuit 21 Modular jack (for telephone only) 22 Switch 23 Drive section 24 Line current detection section 25 Logic Product circuit

Claims (4)

[Claims] 1. A switch for switching a telephone line from a line connection unit to a telephone or a modem, in which one telephone line is switched between a telephone and a modem, a drive unit for driving the switch, and a line current for the modem. A detection unit that detects and outputs a signal at the required current value or more, a hook detection unit that outputs a signal off-hook of the telephone, a signal from the detection unit and a signal from the hook detection unit are calculated, and the signal is output from the hook detection unit. And a logic circuit that outputs a signal when a signal is not output from the detection unit, and the switch is configured to switch the switch to the telephone side via the drive unit based on the signal from the logic circuit. 2. A telephone line comprising a first connecting portion for connecting a telephone and a modem by switching and a second connecting portion for connecting a telephone to another telephone line. A first switch for switching a telephone line to a telephone or a modem, a first drive unit for driving the first switch, a first detection unit for detecting a line current of the modem and outputting a signal at a required current value or more, and an off-hook of the telephone , A second detection unit for detecting a telephone line current of the second connection unit and outputting a signal when the current value is equal to or higher than a required current value, a signal from the first detection unit, and a hook detection unit. A signal from the logic circuit, which is configured to calculate a signal and a signal from the second detection unit, output a signal from the hook detection unit, and output a signal when no signal is output from the first detection unit and the second detection unit. Based on previous A telephone terminal switching device in which a first switch is switched to a telephone side via a first drive unit. 3. A second switch for connecting / disconnecting a telephone line between the second connection unit and a telephone and a second drive unit for driving the second switch are provided, and based on a signal from the logic circuit. 3. The telephone terminal switching device according to claim 2, wherein the second switch is switched to the non-connection via the second drive section. 4. The telephone terminal switching device according to claim 1, wherein a power supply unit is provided and power is supplied to the hook detection unit, the drive unit and the like.