JP2001028637A - Phone call control system having provision for power saving, isdn channel use terminal adaptor using the same and telephone set - Google Patents

Abstract

PROBLEM TO BE SOLVED: To save consumption of a power failure backup battery by making a buzzer circuit with small power consumption available in the vicinity of a telephone set in the case of applying an incoming call notice to the telephone set contained in a terminal adaptor. SOLUTION: Upon the receipt of an incoming call by a terminal adaptor side telephone set control circuit 10, a -48 V feeding ring signal transmission circuit 11 supplies a signal resulting from superimposing a ring signal onto a -48 V power supply to a telephone set 30 usually and a -24 V power supply circuit supplies a -24 V power supply to the telephone set 30 on the occurrence of a power failure. A buzzer circuit 20 that rings when detecting application of a voltage of -30 V--10 V is connected in the vicinity of the telephone set connected to a connection line 40. When the telephone set replies the call and reaches a speech state, a terminal voltage of the telephone set drops to a voltage of <=-10 V and the buzzer circuit stops ringing. Since a ring signal with 75 V rms requiring large power consumption is not used, the current consumption of a battery can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power-saving telephone call control system, a terminal adapter for an ISDN line and a telephone using the same, and more particularly to a battery backup system for accommodating an analog interface telephone in a digital interface exchange subscriber line. A telephone control circuit provided in the terminal adapter for transmitting a ring signal for calling the telephone or for lowering and restoring the voltage of the telephone power supply by a predetermined value, and a buzzer circuit provided near the telephone and detecting a voltage change to ring. And a power-saving telephone call control system comprising:
The present invention relates to a terminal adapter for an SDN line and a telephone using the buzzer circuit.

[0002]

2. Description of the Related Art A terminal adapter is used to accommodate a telephone having an analog interface in a subscriber line of an exchange having a digital interface.
Line terminal adapters are well known. The telephone interface of this terminal adapter generally has a function equivalent to an analog telephone line and a telephone control circuit for supplying voltage and current to the telephone in order to operate the telephone.

[0003] A function of such a telephone control circuit is to activate the telephone to ring when an incoming call is received.
It is necessary to transmit a ring signal equivalent to 5 Vrms.

[0004] On the other hand, recent terminal adapters are compatible with batteries in order to operate at the time of a power failure (usually using a commercial AC power supply). The transmission of the ring signal consumes a large amount of current (power) and greatly affects the battery life.

In order to prevent this, a terminal adapter has a built-in buzzer, and instead of transmitting a ring signal at the time of a power failure, the buzzer sounds to suppress current consumption (power). .

[0006]

However, in the above-described terminal adapter having a built-in buzzer, a telephone (the user) connected near the terminal adapter
Can be used, but there is a disadvantage that a user who uses a telephone remote from the terminal adapter cannot hear the buzzer of the terminal adapter.

A main object of the present invention is to provide a buzzer circuit that consumes a small amount of current (power) near a telephone so that sound can be controlled from a terminal adapter, thereby saving power consumption (power) of a battery. A telephone call control system is provided.

[0008]

SUMMARY OF THE INVENTION A power-saving telephone call control system according to a first aspect of the present invention enables a telephone having an analog interface to be accommodated in a subscriber line of a digital interface, and a commercial AC which is backed up by a battery. When calling the telephone, instead of sending the ring signal to a terminal adapter that supplies a telephone power and a ring signal according to the analog interface to the telephone using a power source, the voltage of the telephone power is used instead of transmitting the ring signal. A telephone control circuit for lowering and restoring the voltage by a predetermined value, and detects a drop of the voltage supplied to the telephone by the predetermined value in the vicinity of the telephone at a connection line connecting the telephone to the adapter and sounds. A buzzer circuit is provided.

According to a second aspect of the present invention, in the power-saving telephone call control system according to the second aspect of the present invention, the buzzer circuit is connected to the connection line via a resistor to adjust the voltage between the connection lines to a predetermined polarity. A voltage detection circuit that monitors an output voltage of the rectifier diode and detects a voltage drop corresponding to the predetermined value, and a self-excited buzzer that sounds according to a detection result of the voltage detection circuit.

According to a third aspect of the present invention, in the power-saving telephone calling control system according to the third aspect, the predetermined value of the voltage drop of the telephone power supply is a difference between the voltage value when the telephone is not answered and the voltage value when the telephone is answered. It is characterized by being a roughly intermediate value.

According to a fourth aspect of the present invention, there is provided a power-saving telephone call control system, wherein the telephone control circuit generates a first voltage value as the power supply for the call, and a first power supply means when the battery is not used. A ring signal generating means for generating a ring signal only when using a battery, a second power supply means for generating a second voltage value lower than the first voltage value only when using a battery, and the first power supply for the telephone. When the first voltage value is supplied from a circuit and a call is made, a ring signal from the ring signal generating means is transmitted to the first signal when the battery is not used.
And a switch for switching to the second voltage value from the second power supply circuit instead of the first voltage value when the battery is used.

According to a fifth aspect of the present invention, there is provided an ISDN line terminal adapter having the telephone control circuit according to the first or fourth aspect.

A telephone according to a sixth aspect of the present invention is characterized in that the buzzer circuit according to the first or second aspect is built in.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an outline of the present invention will be described.
The telephone control circuit of the present invention is used for a telephone interface of a terminal adapter for an ISDN line, and a circuit for controlling a voltage is provided in a portion of a ring signal transmission circuit.
By connecting a buzzer circuit with a voltage detection circuit to the telephone set, a ringing tone for notifying an incoming call is generated on the telephone set by a change in voltage, not by ringing of the telephone set by a ring signal.

In a normal incoming call, a signal in which a ring signal (75 Vrms) is superimposed on -48 V is transmitted from the -48 V power supply / ring signal transmission circuit to the telephone. In the event of a power failure, the -24V supply circuit replaces the ring signal with -24V.
V is supplied to the telephone.

A buzzer circuit for sounding a buzzer by a voltage detection circuit is connected to the telephone. The buzzer circuit detects that -30V to -10V is supplied,
Ring the buzzer. When the telephone responds and enters a call state, the buzzer circuit detects that the voltage has dropped to -10 V or less because the voltage between the terminals of the telephone has dropped,
Stop the buzzer.

As described above, the current consumption (power) can be reduced by connecting the buzzer circuit consuming less current (power) to the telephone and causing the buzzer to sound by a voltage change instead of the ring signal of 75 Vrms. Can be.

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. In FIG. 1, although not shown, the power saving compatible telephone call control system of this example uses a commercial AC power supply as a power supply and a battery interface during power failure to perform backup with a battery. And a two-wire connection line 4 for connecting the telephone 30 to the telephone interface of the terminal adapter for the ISDN line via the telephone control circuit 10.
0 buzzer circuit 20 provided in the vicinity of the telephone set 30.

The telephone control circuit 10 includes a -48V power supply / ring signal transmission circuit 11, a switch circuit 12, a polarity inversion circuit 13, a communication circuit 14, and a -24V power supply circuit 15.
And a control circuit 16 for controlling the whole.

The -48 V power supply / ring signal sending circuit 11 has a ring signal generating circuit 17. The -48V power supply / ring signal sending circuit 11 sends a ring signal (75 Vrms) from the ring signal generating circuit 17 when there is an incoming call at normal times.
Is generated, superimposed on −48 V, passes through the switch circuit 12 and the polarity inversion circuit 13, and passes through the connection line 40 through the telephone 3.
Send a ring signal to 0.

The communication circuit 14 passes through the switch circuit 12 and the polarity inversion circuit 13, and passes through the connection line 40 to the telephone 30.
To send and receive audio.

The -24V power supply circuit 15 supplies -24V to the buzzer circuit 20 through the connection circuit 40 through the switch circuit 12 and the polarity inversion circuit 13 when an incoming call is received during a power failure.

The switch circuit 12 is controlled by a control signal from the control circuit 16 to supply a -48 V power and a ring signal.
1, either the -24V power supply circuit 15 or the communication circuit 14 is selected and connected to the telephone 30 and the buzzer circuit 20 via the polarity inversion circuit 13 and the connection line 40.

The polarity inversion circuit 13 performs polarity inversion in accordance with the connection operation.

FIG. 2 is a block diagram showing a configuration example of the buzzer circuit 20 shown in FIG. 2, the buzzer circuit 20 includes resistors 21 and 22, a rectifier diode 23,
Voltage detection circuit 24, switch 25, constant current circuit 26
And a self-excited buzzer 27.

Each of the two connection lines 40 is connected to a resistor 21
And a rectifier diode 23 via a resistor 22. The resistors 21 and 22 have such a high resistance that the telephone 30 does not affect the call.

The rectifier diode 23 has, for example, a double-wave bridge configuration, regardless of the connection direction of the two connection lines 40.
A voltage having a constant polarity corresponding to the potential difference between the two lines is output.

The voltage detection circuit 24 includes a rectifier diode 23
By monitoring the output voltage, the voltage on the connection line 40 can be recognized, and processing can be performed according to the voltage value. For example, by detecting a voltage of 10 V or more and 30 V or less, the switch 25 is turned on, and the current from the connection line 40 is supplied to the self-excited buzzer 27 via the constant current circuit 26.

The current limit value of the constant current circuit 26 is a minimum value at which the self-excited buzzer 27 sounds, and is 2 to 3 mA in a normal self-excited buzzer. The constant current circuit 26 can be omitted by appropriately setting the resistance values of the resistors 21 and 22.

On the other hand, the telephone 30
A ringer that sounds by a ring signal (75 Vrms) from the -48 V power supply / ring signal transmission circuit 11 (ring signal generation circuit 17) is built in. The current at the time of ringing of this ringer is about 3 mA.

Next, the operation of the present invention will be described with reference to FIGS. 1 and 2 and FIGS. 3 and 4 showing the waveforms of the line voltage at the time of calling the telephone.

FIG. 3 is a diagram showing a voltage waveform in a normal case (commercial power supply is not interrupted: no battery is used). During standby, 48 V from the telephone control circuit 10 is applied between the connection terminals of the telephone 30 and the buzzer circuit 20 for the two connection lines 40. Even when the telephone 30 is called and the ring signal (75 Vrms) is transmitted from the -48 V power supply / ring signal transmission circuit 11 of the telephone control circuit 10, the voltage between the terminals is 4.
Since the voltage becomes 8 V or more, the voltage detection circuit 24 of the buzzer circuit 20 does not operate, and the switch 25 remains OFF.
Therefore, the self-excited buzzer 27 of the buzzer circuit 20 does not ring, and the ringer originally provided in the telephone 30 rings with a ring signal.

When telephone 30 answers this call,
Since the voltage between the terminals of the telephone 30 becomes about 2 V, the voltage detection circuit 24 of the buzzer circuit 20 does not operate, and the switch 25 remains OFF.

FIG. 4 is a diagram showing voltage waveforms in the case of a power outage (commercial power outage: use of batteries). During standby during a power failure, 48V from the telephone control circuit 10 is applied between the terminals of the telephone 30 and the buzzer circuit 20, as in the normal case. Since the voltage between the terminals of the buzzer circuit 20 becomes 48 V or more and the voltage detection circuit 24 does not operate, the switch 25
Remains OFF.

When transmitting the ring signal, the telephone control circuit 10
Instead of transmitting a ring signal from the -48 V power supply / ring signal transmission circuit 11,
24V is supplied. The voltage between the terminal of the telephone 30 and the terminal of the buzzer circuit 20 becomes 24 V, the voltage detection circuit 24 operates, the switch 25 is turned on, the current is supplied to the self-excited buzzer 27 through the constant current circuit 26, and the buzzer sounds. .

On the other hand, the ringer originally provided in the telephone 30 does not ring because no ring signal is transmitted, but since the buzzer circuit 20 is located near the telephone 30,
The user of the telephone 30 can know the call in the same manner as the ringer.

After the telephone 30 responds, the operation is the same as in the normal state. Since the voltage between the terminals of the telephone 30 becomes about 2 V, the voltage detection circuit 24 does not operate and the switch 25 is turned off. This stops the sound of the self-excited buzzer 27.

In the embodiment shown in FIG. 1, the buzzer circuit 20 is separately provided outside the telephone 30. However, the present invention is not limited to this, and the buzzer circuit 20 may be built in the telephone 30.

As described above, by connecting the buzzer circuit with the voltage detection circuit to the telephone, a ringing tone is generated on the telephone by a change in voltage, not by ringing of the telephone by a ring signal. When the current value at the time of signal transmission and the current consumption of the self-excited buzzer are 3 mA, respectively, the voltage of the ring signal is 75 Vrms, and when the self-excited buzzer is sounding, -24 V power is supplied. There is an effect that power consumption can be reduced to about 1/3.

[0041]

According to the present invention, the terminal adapter is provided with a telephone control circuit for lowering and restoring the voltage of the telephone power supply by a predetermined value as a calling signal for informing the telephone of an incoming call, and providing the adapter with the adapter. A buzzer circuit is provided in the vicinity of the telephone connecting line connecting the telephone to detect and drop a predetermined value of the voltage supplied to the telephone so that a ring signal is used when a backup battery is used due to a power failure or the like. Power consumption can be reduced as compared with the case.

[Brief description of the drawings]

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

FIG. 2 is a block diagram showing a configuration example of a buzzer circuit shown in FIG.

FIG. 3 is a diagram showing a connection line voltage waveform when a telephone is called in a normal case.

FIG. 4 is a diagram showing a voltage waveform between connection lines when a telephone is called in the case of a power failure.

[Description of Signs] 10 Telephone control circuit 11 -48V power supply / ring signal transmission circuit 12 Switch circuit 13 Polarity inversion circuit 15-24V power supply circuit 16 Control circuit 20 Buzzer circuit 21,22 Resistor 23 Rectifier diode 24 Voltage detection circuit 25 Switch 26 Constant current circuit 27 Self-excited buzzer 30 Telephone 40 Connection line

Claims (6)

[Claims] A telephone having an analog interface can be accommodated in a subscriber line of an exchange having a digital interface, and a telephone power supply and a ringing signal according to the analog interface are provided to the telephone using a commercial AC power supply backed up by a battery. And a terminal control circuit for lowering and restoring the voltage of the power supply for communication by a predetermined value instead of sending the ring signal when the telephone is called, and A power-saving telephone call control system, comprising: a buzzer circuit that detects a drop of the voltage supplied to the telephone by the predetermined value and makes a sound near the telephone connected to the connection line. 2. A rectifier diode connected to the connection line via a resistor to adjust a voltage between the connection lines to a predetermined polarity, and a buzzer circuit for monitoring an output voltage of the rectifier diode and controlling the output voltage of the rectifier diode by a predetermined value. 2. A power-saving telephone call control system according to claim 1, further comprising: a voltage detection circuit for detecting a voltage drop of said power supply; and a self-excited buzzer that sounds in response to a detection result of said voltage detection circuit. 3. The method according to claim 1, wherein the predetermined value of the voltage drop of the communication power supply is:
2. The power-saving telephone call control system according to claim 1, wherein the voltage value is a substantially intermediate value between the voltage value when the telephone is not answered and the voltage value when the telephone is answered. 4. A telephone control circuit comprising: a first power supply unit for generating a first voltage value as the power supply for a call; a ring signal generation unit for generating a ring signal only when a battery is not used; Only when the second voltage value is lower than the first voltage value.
A second power supply means for generating a voltage value from the first power supply circuit for supplying the first voltage value to the telephone; Switch means for superimposing a ring signal from the second power supply circuit on the first voltage value, and switching to the second voltage value from the second power supply circuit instead of the first voltage value when using a battery. The power-saving telephone call control system according to claim 1, wherein: 5. A terminal adapter for an ISDN line, comprising the telephone control circuit according to claim 1. 6. A telephone having the buzzer circuit according to claim 1 built therein.