JPH0723141A - Feeding circuit - Google Patents

Abstract

PURPOSE:To prevent increase in a subscriber line loss when power consumption of a telephone set is increased by suppressing a feeding current from an exchange main body to an extent and using a secondary battery when the power consumption of the telephone set exceeds the feeding capability of the exchange main body. CONSTITUTION:Power is supplied from a feeding power supply 21 of an exchange main body 20 to a power supply circuit 12 of a telephone set 10 via a subscriber line 30 and converted into a voltage for a telephone set circuit 11 and outputted to a power supply changeover means 15. In this case, the feeding power of the main body 20 is set so that the circuit 11 is functioned normally. In the normal state, a power supply control means 14 of the circuit 11 does not send a battery feeding command signal and the circuit 11 is energized from the circuit 12. In this case, part of the input power is outputted to a secondary battery 13 to charge the battery with a very small current. If a large current is required, the means 14 sends a battery feeding command signal and adds power from the battery 13 to the power from the circuit 12 and outputs the result to the circuit 11. Thus, the circuit 11 consumes a very high current, but the feeding power from the main body 20 is not increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a telephone, and more particularly to a power supply circuit for supplying electric power for operation to a private telephone of a private branch exchange or a key telephone system.

Generally, a telephone, for example, a private telephone for a private branch exchange or a button telephone apparatus operates from a subscriber circuit of the exchange or a main unit of the button telephone apparatus through a subscriber line (hereinafter, referred to as a subscriber line including a private branch wiring). The maximum power that can be used by the telephone set is affected by the DC resistance of the subscriber line. On the other hand, in recent years, the power consumption of telephones has tended to increase as the functionality of the telephones has increased, and along with this, the power loss in the subscriber line has also increased.
For this reason, the scale and price of the subscriber circuit that supplies power including the loss in the subscriber line and the power supply circuit of the button telephone main unit (hereinafter referred to as the switch body) are gradually increasing. In order to prevent the maximum length of the subscriber line from becoming shorter as the voltage drop on the main line increases, it is necessary to limit the power consumption on the telephone side.
Many problems are occurring. Under such circumstances, there is a need for a power supply circuit that supplies less power from the exchange body and has less restrictions on the power consumption of the telephone.

[0003]

2. Description of the Related Art FIG. 10 is a block diagram of a power supply circuit of a conventional telephone. In FIG. 10, only the subscriber circuit portion is illustrated as the exchange main body 70, and the communication path switch, the control device, and the like are omitted. The transmission voice signal from the handset (not shown) in the call circuit 61b of the telephone 60 is the communication control unit.
It is sent to the subscriber line 30 via 61c and the line wheel T _1, and is sent to a communication path switch (not shown) via the line wheel T ₂ in the exchange main body 70. The voice from the main body of the exchange is sent in the opposite direction on the same route. Note that the audio signal between the telephone 60 and the exchange main body 70 is assumed to be in digital format, but analog /
The digital converter and the like are omitted in the figure.

In the telephone circuit 61 in the telephone 60, in addition to the communication circuit section 61b and the communication control section 61c, a key section 61d including a dial key and the like, a display section 61e including an LED (light emitting diode), a liquid crystal display and the like. The main control unit 61a controls each of these parts to exert the function as a telephone.

In FIG. 10, power for operating the telephone circuit 61 is supplied through the following route. That is, the supplied power is output from the power supply 71 in the exchange main body 70 to the subscriber line 30 via the closed loop wheel RET ₂ and the overcurrent protection circuit 72, superposed on the voice signal and sent to the telephone 60, It is separated from the voice signal in the telephone set 60 and is input to the power supply circuit 62 via the closed flow line RET ₁ . The voltage output from the power supply 71 is, for example, −48V, but the power supply circuit 62 converts this into a voltage suitable for the operation of the telephone circuit 61, for example, + 5V, and supplies it to the telephone circuit 61.

In addition to the above, the telephone 60 may be provided with an additional function section 68 such as a modem function. In the case where the additional function section 68 requires special power A
Power may be supplied from a commercial power source using the C adapter 69. However, in the case where such an additional function requiring special power is not provided as described above, the telephone is usually operated only by the power supplied from the exchange main body 70 as much as possible. The present invention is directed to a power supply circuit of a telephone that does not supply power from such a commercial power supply.

As shown in FIG. 10, the power supply circuit of a conventional telephone which does not supply power from a commercial power source
It is usually composed of a power supply 71 of 70, an overcurrent protection circuit 72 and a power supply circuit 62 of the telephone 60 (in addition to this, the telephone 60 and the switch body 70 are provided with closed-circuit line RET ₁ ,
RET ₂ is provided, but these are for separating an AC signal and a DC current and are not directly related to the capability of the power feeding circuit, and hence the description thereof will be omitted hereinafter).

However, since the power feeding circuit configured as shown in FIG. 10 supplies all power through the subscriber line 30, the telephone 60
As the sophistication of the above has progressed, various problems as described later have occurred.

[0009]

The conventional power supply circuit shown in FIG. 10 has the following problems. (1) The higher the functionality of the phone, the higher the power consumption,
Since the power loss in the subscriber line increases, the maximum length of the subscriber line becomes shorter in the high function telephone.

(2) As the power consumption of the telephone increases,
The loss power in the subscriber line (the supply current I, the loss power in the case of the loop resistance R of the subscriber line is I ² R) becomes large, but all of this must be compensated by the power supply source of the exchange main body, so the exchange The power supply of the main body has become larger,
Get expensive.

(3) The operating current of the telephone greatly fluctuates depending on the type of function of the telephone and the usage state of each function, but if this is combined with the condition of the length of the subscriber line length, the input voltage on the telephone side will be in a wide range. Changes to. For this reason,
The power supply circuit of the telephone is required to have a high performance so as to output a stable output voltage against a wide variation of input voltage, and the price becomes high.

(4) In order to reduce the power consumption of the telephone in order to alleviate the above problems, it is necessary to limit the brightness of the LED and the dynamic range of the speaker volume, which deteriorates the telephone function.

(5) An overcurrent protection circuit which detects a short circuit at the far end or near end of the subscriber line as the power consumption of the telephone set and the variation range of the subscriber line resistance increase in the exchange body
72 high performance is required, and the price becomes expensive.

As described above, since the conventional power supply circuit has many problems, there is a need for a power supply circuit which can solve these problems. SUMMARY OF THE INVENTION An object of the present invention is to provide a power supply circuit that supplies less power than the main body of an exchange and has less restrictions on power consumption of a telephone.

[0015]

FIG. 1 is a basic configuration diagram of the present invention, and FIG. 2 is another basic configuration diagram of the present invention. In the figure, 10 and 40 are telephones, 20 and 50 are exchange main bodies, and 30 is a subscriber line connecting between the telephone 10 and the exchange main body 20 or between the telephone 40 and the exchange main body 50.

Reference numerals 11 to 15 are provided in the telephone set 10. Reference numeral 11 is a telephone circuit for performing a function operation as a telephone set in the telephone set 10. Reference numeral 12 is a telephone set by inputting electric power supplied from the exchange main body 20 through the subscriber line 30. A power supply circuit that converts the voltage into a voltage suitable for the operation of the circuit 11 and outputs the converted voltage, and 13 is a power supply circuit for supplying insufficient power to the telephone circuit 11 when the telephone circuit 11 consumes more power than the power supply circuit 12 can supply. A secondary battery, 14 is a power supply control means for sending a battery power supply instruction signal while the telephone circuit 11 performs an operation with large power consumption in the telephone circuit 11, and 15 is an output of the power supply circuit 12 and an output of the secondary battery 13. While receiving the battery power supply instruction signal from the power supply control means 14, the output of the secondary battery 13 is supplied to the telephone circuit 11 in addition to the output of the power supply circuit 12, and the power is supplied when the battery power supply instruction signal is not received. The output of circuit 12 is the telephone circuit 11 Power supply switching means for outputting a weak current to the secondary battery 13 is supplied,
Reference numeral 16 is provided between the secondary battery 13 and the power source switching means 15, and is a secondary battery connecting means for connecting the secondary battery 13 and the power source switching means 15 when the telephone 10 is connected to the subscriber line 30. Is. Reference numeral 21 is a power supply source provided in the exchange main body 20 and supplying power to the telephone set 10 via the subscriber line 30.

Reference numerals 41 to 42 are provided in the telephone 40, 41 is a telephone circuit for performing a function operation as a telephone in the telephone 40, and 42 is a telephone which receives the electric power supplied from the exchange main body 50 through the subscriber line 30. The power supply circuit converts the voltage into a voltage suitable for the operation of the circuit 41 and outputs the voltage.

Reference numerals 51 to 53 are provided in the exchange main body 50, 51 is a power supply power source for supplying electric power to the telephone 40 via the subscriber line 30, and 52 is a predetermined power source for the telephone 40 via the subscriber line 30. Telephone connection detecting means for transmitting a signal and outputting a detection signal by determining that the telephone 40 is connected to the subscriber line 30 when receiving a response signal to the transmission signal from the telephone 40, and 53 is a power supply source It is provided between 51 and the subscriber line 30,
While receiving the detection signal from the telephone connection detection means 52,
A power supply circuit opening / closing means for connecting the power supply power source 51 and the subscriber line 30 to output the output of the power supply power source 51 to the subscriber line 30.

[0019]

The problem with the power supply circuit of the prior art is that the power is supplied entirely through the subscriber line.
In the configuration of FIG. 1, the power supply current from the exchange main body is suppressed within a certain range, and when the power consumption of the telephone exceeds the power supply capacity of the exchange main body, power is supplied from the secondary battery. This method solves the problems of the prior art because the loss in the subscriber line does not increase even if the power consumption of the telephone increases. The operation and action will be briefly described below with reference to FIG.

In FIG. 1, power is supplied from the power supply 21 of the exchange main body 20 through the subscriber line 30 to the power supply circuit 11 of the telephone 10.
The power supply circuit 11 converts the received power into a voltage suitable for the operation of the telephone circuit 11 and outputs the voltage to the power supply switching means 15. It is set enough to operate the function that does not consume large current.

Further, when the telephone circuit 11 is performing a normal operation (including a standby state) in which a large current is not consumed, the power supply control means 14 provided in the telephone circuit 11 does not send the battery power supply instruction signal. Therefore, the power supply switching means 15 is the power supply circuit 12
The input power is output to the telephone circuit 15 which is a load. At this time, a part of the input power is output to the secondary battery 13 to charge the secondary battery 13 with a weak current. This is done in preparation for the case where the power of the secondary battery 12 is needed. .

The telephone circuit 11 operates normally due to the above-mentioned power supply, but when it is in a state where it consumes a large current during operation, the power supply control means 14 instructs the power supply switching means 15 to supply a battery power supply instruction signal. Is sent. Upon receiving the battery power supply instruction signal, the power supply switching means 15 outputs the input power from the secondary battery 13 to the telephone circuit 11 in addition to the input power from the power supply circuit 12. Therefore, the telephone circuit 11 can consume a large current, and the power supplied from the exchange main body 20 does not increase.

In FIG. 1, the telephone 10 is connected to the subscriber line 30, and when the telephone circuit 11 starts operating, the output of the secondary battery 13 is passed through the power source switching means 15 to the telephone circuit.
11 to start the operation of the telephone circuit 11. Also,
When the telephone 10 is not connected to the subscriber line 30 for a long time, the secondary battery 13 continues to supply power to the telephone circuit 11 while the power supply circuit 12 is not outputting the output. Since the secondary battery 13 is consumed, the secondary battery connecting means 16 when the telephone 10 and the subscriber line 30 are not connected
Disconnect the secondary battery 13 from the power switching circuit 15
When the 10 and the subscriber line 30 are connected, the secondary battery 13 and the power supply switching circuit 15 are connected.

Next, the operation and action will be described with reference to FIG.
The telephone connection detecting means 52 of FIG. 2 transmits a predetermined signal to the telephone 40 via the subscriber line 30 in a digital format, for example. When the telephone 40 is not connected to the subscriber line 30, there is no response to the above signal, so the telephone connection detection means 52 determines that the telephone 40 is not connected, and instructs the power supply circuit opening / closing means 53. Detection signal is not transmitted. In this state, the power supply circuit opening / closing means 53 of the exchange main body 50
Is opened, so that power is not supplied to the telephone 40 side.

When the telephone 40 is connected to the subscriber line 30 and the telephone 40 responds to a predetermined signal transmitted from the telephone connection detecting means 52, the telephone connection detecting means 52 detects that the telephone is connected. A detection signal notifying that is sent to the feeding current switching means 53. Power supply current switching means
53 connects the power supply 51 to the subscriber line 30 by this, and power supply is started.

In the configuration shown in FIG. 2, when a short circuit occurs between the two lines of the subscriber line 30 or a ground fault occurs in one or both lines, the telephone connection detection means 52 sends a predetermined line to the subscriber line 30. Since the signal is not received by the telephone 40, the telephone connection detecting means 52 does not receive the response from the telephone 40. At this time, the telephone connection detection means 52 stops the detection signal sent to the power supply current switching means 53, so that the power supply current switching means 53 is opened and power supply to the subscriber line 30 is stopped.

As described above, in FIG. 2, the power supply is stopped even if the subscriber line 30 is cut or short-circuited. Especially, since the latter function is provided, the conventional power supply circuit is always supplied. The overcurrent detection circuit, which was necessary in step 2, is no longer necessary.

[0028]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 3 and 4 are schematic diagrams of a power feeding circuit of an embodiment of the present invention, and FIGS. 5 to 7 are circuit diagrams of an embodiment of the present invention, FIGS.
FIG. 7 is an operation sequence diagram of the embodiment of the present invention.

Throughout the drawings, the same reference numerals indicate the same objects,
10, 40 is a telephone, 11, 41 is a telephone circuit, 12, 42 is a power circuit, 13 is a secondary battery, 14 is a power control unit, 15 is a power switching circuit, 16 is a secondary battery connection unit, 17 is a modular plug , 20,
Reference numeral 50 is an exchange main body, 21 and 51 are power supply sources, 52 is a telephone connection detection unit, 53 is a power supply switch circuit (a mode of realizing the power supply circuit opening / closing means in FIG. 2), and 30 is a subscriber line.

Reference numerals 11a to 11e denote respective parts constituting the telephone circuit 11.
, 11a is the main control section, 11b is the call circuit section, and 11c is the communication control section.
Control part, 11d is a key part, and 11e is a display part. Also,
T₁, T ₂Is a wheel, RET₁, RET₂Is a closed streamline, C
₁~ C₃Is a capacitor, R₁~ R ₆Is resistance, Q₁~ Q₃
Is a transistor, D₁, D₂Is a diode, PC is a
It is Tokapla.

FIG. 3 is a block diagram of an embodiment based on the basic configuration diagram (claim 1) of the present invention shown in FIG. 1, and FIG. 4 is a basic configuration diagram (claim 2) of the present invention shown in FIG. 3 is a configuration diagram of an embodiment based on FIG. 5 and 6 are circuit diagrams of some embodiments of the configuration of FIG. 3, and FIG. 7 is a circuit diagram of some embodiments of the configuration of FIG.

An embodiment of the present invention will be described below with reference to FIGS. The telephone 10 of FIG. 3 can be connected to either the exchange main body 20 of FIG. 3 or the exchange main body 50 of FIG. 4, and the exchange main body 50 of FIG. 4 can be connected to the telephone 40 of FIG.
3 and the telephone set 10 in FIG. 3 can be connected, but for convenience of explanation, the following description will be focused on the case where the telephone set 10 in FIG. 3 and the exchange main body 50 in FIG. 4 are connected by the subscriber line 30. For each other combination of the telephone and the exchange main body, a supplementary explanation will be given each time. Also, FIG.
4 and FIG. 4 show the same range as the configuration of the prior art shown in FIG. 10, and since the configuration and operation of the part excluding the power feeding related part are substantially the same as those of FIG. 10, the description of the overlapping parts will be omitted. .

The telephone and the subscriber line are usually connected by using a telephone cord or a plug, but FIG. 3 shows a state in which the two are connected by a commonly used 4-wire modular plug 17. ing. Two of the four wires are used to connect the subscriber line 30, and the modular plug
By connecting 17 the subscriber line 30 is connected to the subscriber line terminals L ₁ and L ₂ of the telephone 10. In FIG. 3, the other two wires of the modular plug 17 are terminals L ₃ and L _{4 of the} telephone 10.
Connected to.

FIG. 5 shows a circuit diagram of the modular plug 17, and as shown in FIG. 5, the terminals L ₃ and L ₄ of the telephone 10 are shown.
The two wires of the modular plug 17 connected to are previously short-circuited. Therefore, when the modular plug 17 is connected, the terminals L ₃ and L _{4 of the} telephone 10 are connected, and the secondary battery 13 and the power supply switching circuit 15 are connected as shown in FIG. Therefore, a part (including a short-circuit connection part) of the modular plug 17 surrounded by a dotted line in FIG. 5 corresponds to the secondary battery connection part 16 (a realization mode of the secondary battery connection means 16 of FIG. 1).

Although the modular plug 17 is connected as described above, the case where the telephone 10 is not connected to the subscriber line 30 first, that is, the case where the modular plug 17 is not connected will be described. In this state, since the secondary battery connecting portion 16 is open, the secondary battery 13 is not connected to the power supply switching circuit 15. Further, in this state, the power supply circuit 12 of the telephone 10 does not output electric power because it is not connected to the exchange main body 20. Therefore, the power supply switching circuit 15 of the telephone 10 receives no power from either the power supply circuit 12 or the secondary battery 13 and does not supply power to the telephone circuit 11, so that the telephone circuit 11 is in an inoperative state.

In this state, when the modular plug 17 is connected, the subscriber line 30 and the telephone 10 are connected, and at the same time, the secondary battery connection portion 16 is connected and the voltage of the secondary battery 13 is changed to the power supply switching circuit 15 Entered in.

FIG. 6 is a circuit diagram of an embodiment of the power supply switching circuit 15. Below, the power supply at the time when the telephone 10 and the exchange main body 50 of FIG. 4 are connected due to the connection of the telephone 10 and the subscriber line 30. The operation of the switching circuit 15 will be described with reference to FIG.

Since the exchange main body 50 shown in FIG. 4 has not started power supply yet at this time, the power supply switching circuit 15 is provided with the secondary battery 13
Only is connected. That is, no voltage is input to the P _L terminal of the power supply switching circuit 15, but P _B
The output voltage of the secondary battery 13 is input to the terminal.
Depending on the input voltage from the secondary battery 13, the transistor Q
_A base current flows through ₁ , the capacitor C ₁ is charged through the resistors R ₂ and R _5, and the transistor Q ₁ is turned on. When the transistor Q ₁ is turned on, the telephone circuit 11 connected from the P _B terminal to the P _W terminal via the transistor Q ₁
The power of the secondary battery 12 is supplied to.

The main control unit (configured by including not shown microprocessor) 11a in the initial setting in the telephone circuit 11 by the power supply is performed, the power supply from the secondary battery 13 with respect to P _C terminal ( An H-level battery power supply instruction signal (hereinafter, referred to as SW-ON signal) for instructing discharge is output. This signal turns on the transistor Q ₂ of the power supply switching circuit 15, so that the transistor Q ₁ remains on regardless of the charging state of the capacitor C _3, and the secondary battery 13 continues to supply power to the telephone circuit 11. .

On the other hand, when the exchange main body is the exchange main body 20 shown in FIG. 3, the power supply circuit 12 of the telephone 10 receives power from the exchange main body 20 due to the connection of the modular plug 17 so that the power is supplied constantly. The output is sent to the power supply switching circuit 15. At this point, the power supply switching circuit 15 shown in FIG.
Of P _C H level SW-ON signal from the power control unit 14 it is not sent to the terminal, but is in a state in which L-level SW-OFF signal is input, SW-ON to P _C terminal /
The output of the power supply circuit 12 is supplied to the telephone circuit 11 via the power supply switching circuit 15 regardless of which signal is OFF. Therefore, the time when the telephone circuit 11 starts operating does not change whether the exchange main body is the exchange main body 20 of FIG. 3 or the exchange main body 50 of FIG.

The operation will be described below with reference to FIGS. 3 and 4. When the telephone circuit 11 starts to operate by the power supply from the secondary battery 13, the telephone connection detection unit 52 of the exchange main body 50 inputs the data to the main control unit 11a via the subscriber line 30 and the communication control unit 11c in the telephone 10. The processing unit (not shown) of the main control unit 11a returns a response signal to the signal. This response signal is a signal for requesting power supply (POW-ON request signal), which is sent from the processing unit of the main control unit 11a to the subscriber line 30 via the communication control unit 11c and the telephone connection of the exchange main body 50. It is received by the detection unit 52. The telephone connection detection unit 52 detects that the telephone 10 is connected to the subscriber line 30 based on this response signal, and outputs an H level power supply instruction signal (hereinafter referred to as POW-ON signal) to the power supply switch circuit 53. Output.

FIG. 7 is a circuit diagram of an embodiment of the power feeding switch circuit 53, and FIG. 7 will be described below. When the POW-ON signal is not output from the telephone connection detection unit 52, an L level (ground potential) signal (hereinafter referred to as POW-OFF signal) is input to the CNT terminal of the power supply switch circuit 53. . The POW-OFF signal is a signal for instructing to stop the power supply. However, when the POW-OFF signal is being input, the transistor portion of the photocoupler PC is in the off state, so the transistor Q ₃ is in the off state. There is. Therefore, it is input to the P ₁ terminal from the power supply 51.
48V is not output to the P ₃ terminal, and power is not supplied to the subscriber line 30.

In this state, the telephone connection detection unit 52 causes the CNT
When an H level POW-ON signal is input to the terminal, a current flows in the diode portion of the photocoupler PC and the transistor portion is turned on, so that the transistor Q ₃ is turned on and the telephone line 10 is sent to the telephone 10 via the subscriber line 30. Power supply is started. At this time, the telephone connection detection unit 52 sends a POW-ON completion signal notifying that the power supply is started.
It is sent to 10 (details will be described later). When the exchange main body is the exchange main body 20 shown in FIG. 3, power supply to the telephone 10 is started immediately when the telephone 10 is connected to the subscriber line 30 without going through the above-mentioned process as described above. It becomes a state.

The main control section 11a of the telephone 10 shown in FIG.
ON completion signal feed than the secondary battery 13 against P _C terminal of the power supply switching circuit 15 receives (discharge) L level of the battery power supply stop instruction signal for instructing the stop of (hereinafter, SW-OFF
Signal).

[0045] P _C terminal in the power supply switching circuit 15 of FIG. 6 when the L-level SW-OFF signal is input transistor Q
₂ is turned off and the transistor Q ₁ is also turned off. As a result, the power supply from the secondary battery 13 is stopped, but instead, the voltage of the power supply circuit 12 whose input is started at the P _L terminal is output to the P _W terminal via the diodes D ₂ and D ₁ . That is, power is supplied to the telephone circuit 11 from the exchange main body 50.

At this time, the power supply circuit input to the P _L terminal
At the same time, the voltage of 12 is output to the P _L terminal through the resistor R ₁ , so charging of the secondary battery 12 is started. This charging is to keep the secondary battery 12 in a charged state at all times,
Since the resistance value of the resistor R ₁ is large, the charging is charging with a minute current (trickle charging). Therefore, this charging does not significantly increase the power supply current from the exchange main body 50 or the exchange main body 20.

From this point, the telephone circuit 11 shown in FIG. 3 is operated normally by the power supplied from the exchange main body 50, for example, the exchange main body.
Although the response signal for confirming the reception is returned to the signal sent from the telephone 50, the telephone 10 has the exchange main body shown in FIG.
Even in the case of 20, that is, the configuration in which the power supply voltage is constantly output, the operation at this point is the same.

When a state in which a large current is consumed during operation, for example, an incoming call is made to the telephone 10 and a ringer sound is transmitted to a speaker (not shown), the main control unit is activated. The processing unit in 11a sends an H-level SW-ON signal to the power supply switching circuit 15 via the power supply control unit 14.

When the SW-ON signal is input to the _PC terminal, the power supply switching circuit 15 of FIG. 6 turns on the transistor Q ₂ and then turns on the transistor Q _{1 as} well, so that it is input from the secondary battery 13. The voltage is output to the telephone circuit 11 via the transistor Q ₁ . At this time, since the electric power input from the power supply circuit 12 is continuously supplied to the telephone circuit 11, the telephone circuit 11 is supplied with power from both the exchange main body 20 and the secondary battery 13. Therefore, even if the telephone circuit 11 performs an operation that consumes a large current, the power supplied from the exchange main body 20 does not increase. When power is being supplied from both the power supply circuit 12 and the secondary battery 13, even if the output voltage of the secondary battery 13 becomes higher than the output voltage of the power supply circuit 12, the power supply switching circuit 15 has diodes D ₁ and D _2. Is provided, the voltage of the secondary battery 13 is not sent to the subscriber line 30 side.

When the telephone 10 responds and the handset (not shown) goes off-hook, the main controller 11a stops sending the ringer tone, but the power controller 14 which receives the response information from the processor turns on the power. The SW-OFF signal is sent to the switching circuit 15. In the power supply switching circuit 15 of FIG. 6, the transistor Q ₂ is turned off by receiving this signal, and then the transistor Q ₁ is also turned off. Therefore, the power supply from the secondary battery 13 is stopped, and the power supply to the telephone circuit 11 is performed by the power supply circuit 12. However, in this state, trickle charging of the secondary battery 13 by the input from the power supply circuit 12 is restarted in this state to recover the consumed secondary battery 13.

Thereafter, the power supply control unit 14 sends out a SW-ON signal or SW-OFF to the power supply switching circuit 15 in accordance with the operation of the processing unit of the main control unit 11a, and only when an operation with large power consumption is performed. Power is supplied from the secondary battery 13 in addition to the power supplied from the exchange main body 50 or the exchange main body 20.

Here, the switch main body 20 of FIG. 3 and the telephone set 40 of FIG. 4 will be supplemented. In the above, the telephone connection detection unit 52 of FIG. 4 is described as a portion that detects only whether or not a telephone is connected, and it is assumed that the exchange main body 20 of FIG. 3 does not have a portion corresponding to the telephone connection detection unit 52. I've been However, when the signal between the telephone and the exchange main body is in digital form, the exchange main body monitors and controls the state of the telephone 10 by exchanging the digital signal. Therefore, the exchange main body 20 in FIG. 3 also has such a signal exchange function. is doing. The exchange main body 50 of FIG. 4 also has a function of transmitting and receiving various signals for monitoring and controlling the telephone, in addition to detecting only whether or not the telephone is connected. Therefore, the telephone 10 of FIG.
It is possible to discriminate whether or not the power consuming operation is performed by the signal received from the exchange main body regardless of whether the exchange main body 20 of FIG. 3 or the exchange main body 50 of FIG. 4 is connected. In other words, the only difference between the exchange main body 20 of FIG. 3 and the exchange main body 50 of FIG. 4 is whether or not the power feeding circuit is opened or closed depending on the detection result of whether or not the telephone is connected to the subscriber line 30.

On the other hand, although details are not shown in the telephone 40 of FIG. 4, when the telephone receives a signal from the exchange main body, the telephone has a function of returning a response signal to the signal as described above. Since it is general, the telephone 40 also has this function like the telephone 10. Therefore, the telephone 10
The telephone 40 is different only in the power supply circuit.

Next, the sequence of operations for controlling the power supply switching circuit according to changes in power consumption in the telephone circuit will be described with reference to FIGS. 8 and 9, but the differences in operation between the embodiments of FIGS. 3 and 4 are described. Has been explained above,
Only the operation sequence when the telephone 10 of FIG. 3 and the exchange main body 50 of FIG. 4 are connected will be described below. In addition,
a-1, a-2 to j-1, j-2 are telephones 10 shown in FIGS. 8 and 9.
And a code for identifying the signal between the exchange main body 50,
Are codes for identifying the state at each time point in the sequences of FIGS. 8 and 9. In addition, the word * indicating the state in FIGS. 8 and 9 indicates that the operation is performed manually.

Signals between the telephone set 10 and the exchange main body 50 are digitally transmitted and received through the subscriber line 30, and the telephone set 10 responds to a polling signal transmitted from the exchange main body 50 side at a constant cycle. Although it is premised that the response signal is sent back from the side, the polling interval is not shown at a constant interval for convenience of description in FIGS. 8 and 9.

FIG. 8 shows an example of control of the power supply circuit in the telephone 10 in accordance with a change in current consumption. The figure illustrates the sequence from the state where the telephone 10 is not connected to the subscriber line 30. Telephone line 10 is subscriber line 30
Even when the telephone is not connected to the telephone, the telephone connection detection unit 52 of the exchange main body 50 periodically sends a signal in the polling format. In FIG. 8, the signal is used as an RST (reset) command (a-1), but since the telephone set 10 is not connected to the subscriber line 30, there is no response to the RST command (a-2).

Here, when the telephone 10 is connected to the subscriber line 30 by the modular plug 17 (state), the telephone circuit is
Since the secondary battery 13 supplies power to the telephone 11, the telephone circuit 11 starts operating. As a result, the telephone 10 responds to the next RST command (b-1). This response is a request for power supply to the exchange main body 50 (POW).
-ON request) (b-2). Based on this response, the telephone connection detection unit 52 of the exchange main body 50 identifies that the telephone 10 has been connected, and the POW-
The ON signal is sent, and the power supply 51 of the exchange main body 50 starts power supply to the telephone 10 (state).
A POW-ON completion signal is sent from the telephone 10 (c-1).

In the telephone 10, the main control section 11a receives this, and the power control section 14 sends a SW-O signal to the power switching circuit 15.
Since the FF signal is transmitted, the power supply from the secondary battery 13 to the telephone circuit 15 is stopped (state). Here, the main control unit 11a receives the reception confirmation signal for the POW-ON completion signal (hereinafter,
It will be returned (c-2). Phone 10 is in this state waiting until some event occurs,
Acknowledged by polling from the switch body 50 each time
However, the signal in the standby state is omitted in the figure.

When there is an incoming call to the telephone set 10, the exchange main body 50 sends a calling signal to the telephone set 10,
In response to this, the telephone set 10 returns ACK (d-1, d-2).
The call of the incoming call is made by the speaker of the communication circuit 11c (not shown).
It is normal to ring the ringer sound, but since the operation of the ringer circuit (not shown) requires a large amount of power, the main control unit 11a uses the power supply control unit 14 to switch the power supply switching circuit.
A SW-ON signal is sent to 15 (state), and then a ringer sound sending process is performed (state).

This state continues until the telephone 10 responds. During that time, the exchange main body 20 performs polling by the NOP signal (a signal not instructing the operation) to monitor the response, and the telephone 10 responds to this polling. First, it returns the fact that it is ringing, and ACKs the subsequent NOP signals.
Is returned (e-1, e-2, f-1, f-2).

When the handset of the call circuit section 11b is off-hook or the answer button (not shown) is pressed in the telephone set 10, the main control section 11a stops the ringer (state), and then the power control section 14 turns on the power. SW-in the switching circuit 15
An OFF signal is sent to stop the power supply from the secondary battery 13 (state). The control unit 11a also returns the next NO
A response signal is returned to the P signal (g-1, g-2). The telephone 10 starts the call by the handset by off-hook, but during the call, the A
CK is returned (h-1, h-2).

Here, it is assumed that the caller presses the speaker button (not shown) of the key portion 11d in order to switch the call from the handset to the speaker. Since the current consumption increases when the speaker is operated, the main control unit 11a sends a SW-ON signal to the power switching circuit 15 via the power control unit 14 (state), and then controls the call circuit 11b to turn on the speaker. Since the speaker is in the operating state (state), the speaker is in the speaker receiving state. After that, ACK is returned from the telephone 10 side in response to the NOP signal sent from the exchange main body 20 in order to monitor the change in the telephone state such as the end of call (i-1, i-2, j-1, j-
2).

After that, the SW-ON signal is sent from the power supply control unit 14 and is backed up from the secondary battery 13 only while the telephone circuit 11 performs a predetermined operation as a power-consuming operation.

Next, the operation sequence when the modular plug 17 is unplugged from the telephone set 10 side will be described with reference to FIG. 9. The sequence (a-1 to f in FIG. 9) until the ringing state for an incoming call is described. -2 and states-states) are exactly the same as those in FIG. 8, so only the subsequent sequence will be described.

After the state, it is assumed that the modular plug 17 is pulled out by the ringer for some reason during the calling (state). Even in this state, the exchange main body 50 waits for a response and continues to output the NOP signal, but since the telephone 10 and the subscriber line 30 are not connected, the state in which no signal is returned from the telephone 10 continues (g-1, g-2, h-1, h-2). If this state continues for a certain period of time or more, the telephone connection detection unit 52 of the exchange main body 20 will time out.

When the time is over, the telephone connection detection unit 52
Sends a POW-OFF signal to the power feeding switch circuit 53, so that the power feeding switch circuit 53 stops the power feeding from the power feeding power source 51 (state). After the power supply is stopped, the exchange main body 50 continues to send the RST signal to the telephone 10, but this state is the same as the state before the telephone 10 and the subscriber line 30 were connected, and the response from the telephone 10 side is Naturally not done (i-1, i-2, j-1, j-2). As described above, in the configuration of FIG. 3, the power supplied from the exchange main body 20 or the exchange main body 50 to the telephone set 10 is set to a capacity sufficient for the telephone circuit 11 to perform an operation that does not particularly require a large amount of power. Power is supplied from the secondary battery 13 to the telephone circuit 11 only when performing an operation requiring a large amount of power. For this reason,
Even if the power consumption in the telephone circuit 11 increases, the exchange main body
20 or the power supply current sent from the exchange main body 50 through the subscriber line 30 does not increase.

Further, in the exchange main body 50 having the configuration shown in FIG. 4, the telephone connection detecting unit 52 is connected to the subscriber line 30 when the two lines of the subscriber line 30 are short-circuited or one or both lines are grounded. Since the predetermined signal being sent is not received by the telephone 40, the telephone connection detection unit 52 will not receive a response from the telephone 40. At this time, the telephone connection detection means 52 stops the detection signal being sent to the power supply current switching means 53,
The power supply current switching means 53 is opened to stop power supply to the subscriber line 30. Therefore, the power supply is stopped regardless of whether the subscriber line 30 is disconnected or short-circuited. In particular, by having the latter function, the overcurrent detection used in the conventional power supply circuit that always supplies power is detected. No circuit is needed.

Although the embodiment of the present invention has been described above with reference to FIGS. 3 to 9, FIGS. 3 to 9 are merely illustrations of an embodiment of the present invention, and only the embodiment of the present invention is shown. It goes without saying that it is not limited. For example, in FIGS. 3 and 4, the secondary battery connecting portion 16 is realized by the modular plug 17, but it goes without saying that the secondary battery connecting portion 16 is not limited to the modular plug.
Even if the names of signals and commands in the sequence diagrams of FIGS. 8 and 9 are different from those shown, the effect of the present invention does not change.

[0069]

As described above, in the present invention,
The power supplied from the main switch unit to the telephone is set to a capacity sufficient for the telephone to operate without requiring a large amount of power, and when the telephone performs an operation requiring a large amount of power, power is supplied from the secondary battery. Therefore, even if the power consumption of the telephone increases, the power supply current sent from the exchange main body through the subscriber line does not increase, and the loss in the subscriber line does not increase. Therefore, even if the power consumption of the telephone is increased, the maximum length of the subscriber line is not shortened. Further, since the invalid power loss in the subscriber line does not increase, it is not necessary for the power supply source of the exchange main body to supply power up to the loss in the line, and the capacity of the power source can be reduced.

Further, since the value of the power supply current from the main body of the exchange does not change greatly, the change in the voltage supplied to the phone is small even if the current consumption of the phone and the fluctuation of the subscriber line resistance are large. Therefore, it is not necessary to provide the power supply circuit in the telephone with a high performance capable of supplying electric power of a stable voltage to a wide range of input voltage. Further, even if the current consumption of the telephone increases, the maximum length of the subscriber line does not become short, so that it is not necessary to place a restriction on the power consumption of the telephone. Therefore, the brightness of the LED, the dynamic range of the speaker volume, and the LED that can be turned on at the same time
There is no need to set restrictions on the number of telephones and so on, and the enhancement of the functionality of the telephone is not hindered.

Further, in the present invention, the telephone connection detection means detects whether or not the telephone is connected by transmitting and receiving a signal without monitoring the state of the telephone with a direct current, and joins when the telephone is not connected. Since the power supply is controlled not to be supplied to the main line, it is not necessary to stop the power supply by the overcurrent detection circuit even if the subscriber line is short-circuited. As a result, the overcurrent detection circuit can be removed.

As described above, the present invention greatly contributes to the simplification and economic efficiency of the power supply circuit including the power supply power supply of the exchange main body and the power supply circuit of the telephone and the improvement of the telephone function.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram (1) of the present invention.

FIG. 2 is a basic configuration diagram of the present invention (2)

FIG. 3 is a configuration diagram (1) of a power supply circuit according to an embodiment of the present invention.

FIG. 4 is a diagram of a power supply circuit according to an embodiment of the present invention (2)

FIG. 5 is a circuit diagram (1) of an embodiment of the present invention.

FIG. 6 is a circuit diagram of an embodiment of the present invention (2)

FIG. 7 is a circuit diagram of an embodiment of the present invention (3)

FIG. 8 is an operation sequence diagram (1) of the embodiment of the present invention.

FIG. 9 is an operation sequence diagram (2) of the embodiment of the present invention.

[Fig. 10] Conventional power supply circuit configuration diagram

[Explanation of symbols]

 10, 40 Telephone 11, 41 Telephone circuit 12, 42 Power supply circuit 13 Secondary battery 14 Power supply control means 15 Power supply switching means 16 Secondary battery connection means 20, 50 Switch main body 21, 51 Power supply 52 Telephone connection detection means 53 Power supply circuit Switching means 30 Subscriber line

Claims (2)

[Claims] 1. A telephone line (10), which is supplied with power from a power supply source (21) of an exchange main body (20) through a subscriber line (30), and the subscriber line (20) from the exchange main body (20). Power supply circuit (12) for inputting the power supplied through 30) and converting it to a voltage suitable for the operation of the telephone circuit (11) and outputting it, and the telephone circuit (11) having the supply capability of the power supply circuit (12). A secondary battery (13) for supplying insufficient power to the telephone circuit (11) when consuming more power than the power consumption of the telephone circuit (11) in the telephone circuit (11). Power supply control means (14) for sending a battery power supply instruction signal, and the output of the power supply circuit (12) and the output of the secondary battery (13) are input while the power supply control means (14) is operated. ) From the power supply circuit (12) the output of the secondary battery (13) while receiving the battery power supply instruction signal
In addition to the output of the power supply circuit (11), when not receiving the battery power supply instruction signal, the power supply circuit (12)
Power source switching means (1) for supplying a weak current to the secondary battery (13) while supplying the output to the telephone circuit (11).
5), provided between the secondary battery (13) and the power source switching means (15), the secondary battery (13) when the telephone (10) is connected to the subscriber line (30). ) And a secondary battery connecting means (16) for connecting the power source switching means (15) to each other. 2. A subscriber line (3) from a built-in power supply (51).
Switch main unit (5) that supplies power to the telephone (40) via
In (0), a predetermined signal is transmitted to the telephone (40) through the subscriber line (30), and when the telephone (40) receives a response signal to the transmission signal, the telephone (40) ) Is connected to the subscriber line (30) and outputs a detection signal to the telephone connection detection means (52), provided between the power supply (51) and the subscriber line (30) And the power supply (51) and the subscriber line (30) while receiving the detection signal from the telephone connection detection means (52).
A power supply circuit comprising: a power supply circuit opening / closing means (53) for connecting an output of the power supply power supply (51) to the subscriber line (30).