JP2001237995A - Charging system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently charge an electrolytic capacitor by obtaining a power source from a telephone line when it is opened. SOLUTION: A charging circuit 31 is provided with a transistor 31Q for short-circuiting the both ends of a high resistance 31R in parallel with the high resistance 31R for charging a high voltage which is generated in the opened telephone line 2 to the electrolytic capacitor 32 by a little current. The transistor 31Q is turned on for a prescribed period t immediately after opening the line 2 so that the current being larger than the one at the side of the resistance 31R is obtained from the line 2 to charge the capacitor 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a charging system,
In particular, the present invention relates to a charging method for charging a power supply used in a device connected to a telephone line with a current obtained from the telephone line.

[0002]

2. Description of the Related Art In general, various devices connected to a telephone line, such as a telephone device and a line selection device, use an AC power supply as an operating power supply. Installation is not possible and the installation place is restricted, and AC power is consumed by standby current. Further, the power supply circuit also has a relatively large configuration, which causes an increase in cost and an increase in the size of the device.

As a configuration for solving such a problem, a method of using a small current obtained from a telephone line as an operation power supply can be considered. Normally, when a telephone line is seized, a DC loop current of 20 mA or more flows, but its voltage is low. On the other hand, when a two-wire telephone terminal is directly connected to a general subscriber telephone line, a relatively high voltage is supplied when the telephone line is opened. Therefore, when a higher voltage than the low voltage obtained from the loop current at the time of capturing the telephone line is required as the operating power supply, a current in a predetermined range may be obtained from the open telephone line and charged.

[0004]

Here, when the telephone line is released, there is a possibility that an incoming signal may come from the exchange.
It is necessary to provide a high resistance in order to protect the withstand voltage of the capacitor. However, when charging via a high resistance, the charging current is small. For this reason, when the consumption of the operating power exceeds the charging speed, there is a problem that the voltage of the operating power drops. An object of the present invention is to solve such a problem, and an object of the present invention is to provide a charging method that can obtain power from an open telephone line and charge efficiently.

[0005]

In order to achieve such an object, a charging method according to the present invention comprises a capacitor for storing a high voltage generated in an open telephone line, and a capacitor for storing a high voltage slightly from the open telephone line. A charging circuit for charging the capacitive element with the obtained first current, wherein the charging circuit has a second current larger than the first current for a predetermined period immediately after the telephone line is opened.
Is obtained from the telephone line to rapidly charge the capacitive element. The charging circuit may include a resistance element for obtaining a first current from an open telephone line, and switching means for short-circuiting both ends of the resistance element to obtain a second current. . Further, in the charging circuit, after the loop current of the telephone line is cut off, quick charging may be performed for a predetermined period immediately after the unused state of the telephone line is confirmed.

[0006]

Next, the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of a line selecting apparatus to which a charging method according to an embodiment of the present invention is applied. Hereinafter, a line selection device will be described as an example of a device connected to a telephone line. However, the present invention is not limited to this, and can be widely applied to a device connected to a telephone line. In the figure, a line selecting device 1 is connected between a telephone line 2 from an exchange (not shown) and a two-wire type (analog) telephone terminal 4.
Connected through.

In the line selection device 1, reference numeral 12 denotes a terminal power supply circuit for supplying power to the telephone terminal 4 via the terminal line 3, and 11
Is a line relay for switching and connecting either the telephone line 2 or the terminal power supply circuit 12 to the terminal line 3, and 13 is a terminal relay provided on the telephone terminal 4 side of the line relay 11 and detects a terminal loop current flowing through the terminal line 3 to detect a terminal loop. This is a terminal loop detection circuit that outputs a signal 13A.

Reference numeral 15 is connected to a rectified output 14A of a diode bridge 14 connected to both ends of the telephone line 2. The line 15 closes the telephone line 2 to perform line capture and output a dial pulse signal (DP) signal. This is a line capture DP transmission circuit. The line capture DP transmission circuit 15 closes the loop based on the line capture DP transmission signal 15B, and outputs a part of the loop current flowing through the telephone line 2 when the loop is closed as a loop connection output 15C. Further, it outputs a dial pulse signal corresponding to the dial number specified by the line capture DP transmission signal 15B.

Reference numeral 16 denotes a loop from the line capture DP transmission circuit 15.
High impedance circuit connected to loop closed output 15C
(Hereinafter, referred to as HI-Z circuit), 17 is HI-Z circuit 1
A part of the loop closing output 15C obtained through the terminal 6
Power supply V_AThe electrolytic capacitor is charged as
Terminal supply power V charged in the capacitor 17_ATo
A diode for backflow prevention output to the terminal power supply circuit 12,
18 is the terminal power supply V _ATo the rechargeable battery 19
The operating power supply V required for each circuit_CCSupply and terminal supply
Power supply V_AOperating power V of the rechargeable battery 19_CCTo
It is a power supply circuit to supply. As a result, the line selection of the present invention
The switching device 1 operates only with the power capacity obtained from the telephone line 2.
Operation becomes possible, and an AC power supply is unnecessary.

Reference numeral 21 denotes a PB receiving circuit which is connected to the loop closed output 15C and receives a PB signal from the telephone line 2;
Is a PB transmission circuit for transmitting a PB signal to the telephone line 2 via the HI-Z circuit 16; 24 is a tone output circuit for outputting various tones to the telephone terminal 4 via the terminal power supply circuit 12;
23 is a relay control circuit for controlling the line relay 11, 25
Is an incoming detection circuit for detecting an incoming signal from the telephone line 2;
Reference numeral 6 denotes a reverse detection circuit for detecting a reverse signal indicating a response from the telephone line 2 at the time of calling, and 10 a line selection device 1.
And a CPU (control circuit) 27 for controlling each circuit section, a storage circuit for storing line selection information used for line selection.

[0011] 30 Of the dial pulse signal from the telephone terminal 4, a high voltage power supply circuit for supplying a high voltage power supply V _B to the break period. In the high voltage power supply circuit 30, an electrolytic capacitor (capacitive element) a portion of the rectified output 14A upon opening of the telephone line 2 as the high voltage power source V _B is 31 3
A charging circuit 33 for charging the battery 2 and for performing a quick charge for a predetermined period immediately after the opening of the telephone line in response to the quick charge signal 31A.
5A and the terminal loop detection signal 13A from the terminal loop detection circuit 13, the high voltage power supply V _{B is} supplied to the telephone terminal 4 via the terminal power supply circuit 12 only during the break period of the dial pulse signal from the telephone terminal 4. power supply control circuit for supplying, 34 is a diode for backflow prevention which outputs a high voltage power supply V _B from the power supply control circuit 33 to the terminal power supply circuit 12.

FIG. 2 is a circuit diagram showing a configuration example of a high-voltage power supply circuit. In the figure, a charging circuit 31 is connected in series between a rectified output (positive side) 14A of a diode bridge 14 and a positive terminal of an electrolytic capacitor 32, and has a high resistance 31R for limiting a charging current to the electrolytic capacitor 32; A diode 31 connected in series to the high resistance 31R to prevent a reverse current from flowing from the electrolytic capacitor 32 to the rectified output 14A.
D. Accordingly, while securing a predetermined impedance even when opening the telephone line 2, it can charge the high voltage power source V _B to the electrolytic capacitor 32.

A transistor (switching means) 31Q is provided in parallel with the high resistance 31R, and a transistor 31T is connected to the base side of the transistor 31Q. The quick charge signal 31A from the CPU 10 is connected to the base of the transistor 31T. Thereby, when the quick charge signal 31A is turned on, the transistor 31T and the transistor 31
Q is turned on, and both ends of the high resistance 31R are short-circuited. Then, a current (second current) larger than the current (first current) flowing through the high resistance 31R is supplied to the electrolytic capacitor 32 via the transistor 31Q, and rapid charging is performed.

The power supply control circuit 33 includes an electrolytic capacitor 32
A photocoupler 33P having an output terminal connected in series between the positive terminal of the photocoupler 33 and the anode terminal of the diode 34, and an operation power supply V to one of the input terminals of the photocoupler 33P when the power supply control standby signal 15A indicates a line capturing state. _The transistor 33T for supplying _CC and the terminal loop detection signal 13
During the period in which A indicates that the terminal loop current is off, the photocoupler 3
MOSFE for connecting the other of the 3P input terminals to the ground potential
T33F. This allows the photocoupler 33P to be in a line capturing state and a period during which the terminal loop current is turned off, ie, during a break period of the dial pulse signal.
There turned on, the high voltage power supply V _B being charged is supplied to the terminal power supply circuit 12 via a diode 34 to the electrolytic capacitor 32.

Next, the operation of the present invention will be described with reference to FIG. FIG. 3 is a timing chart showing the operation of the line selection device. In the on-hook state where the telephone terminal 4 is not used, the terminal loop detection circuit 13 does not detect the terminal loop current of the terminal line 3 and the terminal loop detection signal 1
3A is in an OFF state. The CPU 10 constantly monitors the terminal loop detection signal 13A, and when the terminal loop detection signal 13A is turned on, the telephone terminal 4
Is detected, and the on-hook state of the telephone terminal 4 is detected when the terminal loop detection signal 13A is turned off for a period longer than the hooking time.

Before the time T1, the telephone line 2 is open, and the line voltage V _L across the telephone line 2 is about 48 V in a general subscriber telephone line. This voltage appears at the rectified output 14A via the diode bridge 14, and this is charged to the electrolytic capacitor 32 while maintaining high impedance by the charging circuit 31. At this time,
Although a voltage drop occurs between the diode bridge 14 and the diode 31D, about 46 V is applied to the electrolytic capacitor 32.
A high voltage power supply V _B is charged. Since the backflow preventing diode 31D is provided, even if the line voltage _VL of the telephone line 2 decreases due to a loop closure or the like,
Voltage of the high voltage power supply V _B is not lowered.

At time T1, if the telephone terminal 4 goes off-hook and the terminal line 3 is captured, the telephone line 2
Is supplied to the telephone terminal 4, and this loop current is detected by the terminal loop detection circuit 13, and the terminal loop detection signal 13A is turned on. When the CPU 10 detects the off-hook state of the telephone terminal 4 based on the terminal loop detection signal 13A, the CPU 10 sets the hook state information 10A inside the CPU to the OFF state, and controls the power supply control standby signal 15A to the ON state. The telephone line 2 is captured by closing the loop of the telephone line 2 by the line capture DP signal transmission circuit 15. Then, the line relay 11 is switched from the telephone line 2 side to the terminal power supply circuit 12 side, and the terminal power supply circuit 12 supplies a terminal loop current. As a result, the telephone terminal 4 starts operating by the terminal loop current from the line selection device 1.

At time T2, when a dial pulse signal is output from the telephone terminal 4, the terminal loop current flows during the make period, and the terminal loop current stops during the break period. Therefore, the terminal loop detection signal 13A from the terminal loop detection circuit 13 indicates the ON state during the make period of the dial pulse signal, and the ON state during the break period.
This indicates the F state. At this time, the power supply control circuit 33
Transistor 33T has an ON state (LOW level)
Since the power supply control standby signal 15A of is applied, the power supply V _CC through a transistor 33T is supplied to the input side of the photocoupler 33P.

Therefore, when the terminal loop detection signal 13A is turned off (High level) in accordance with the break period, the MOSFET 33F of the power supply control circuit 33 is turned off.
Turns on, a current flows through the input-side LED of the photocoupler 33P, and the output-side transistor of the photocoupler 33P turns on. The high voltage power supply V _B charged in the electrolytic capacitor 32 is supplied to the diode 34 via the photocoupler 33P. Thus, the break period dial pulse signal, a high voltage power supply V _B is supplied to the telephone terminal 4 via the terminal power supply circuit 12 and the terminal lines 3, it is charged therein as an operating power supply of the telephone terminal 4.

[0020] Thus, the electrolytic capacitor 32 to charge the small current derived from the telephone line 2 during the opening of the telephone line 2 as the high voltage power source V _B is provided, when the dial pulse signal is transmitted from the telephone terminal 4 . Thus supply high-voltage power supply V _B via the terminal power supply circuit 12 and the terminal line 3 from the dial pulse signal of the break period power supply control circuit 33 to the telephone terminal 4, the dial pulse signal is continuously transmitted Even under such bad conditions, a relatively high voltage can be supplied from the line selection device to the telephone terminal, and the two-wire telephone terminal can be operated stably.

At the same time, the CPU 10 detects a dial pulse signal from the telephone terminal 4 based on a change in the state of the terminal loop detection signal 13A in the line capture state,
Detect the outgoing call destination phone number. Then, after the transmission of the dial pulse signal is completed, the line selection information in the storage unit 27 is searched based on the telephone numbers obtained so far, and the line service with the lowest call charge is selected. And
At time T3, a line capture DP transmission signal 15B indicating the line selection number for selecting the line service and the telephone number of the other party following the line selection number is output. This allows
A dial pulse signal is output from the line capture DP sending circuit 15 to the telephone line 2.

After the transmission of the dial pulse signal to the telephone line 2 is completed, the called party is in a call state, and the line relay 11 is controlled to switch the terminal line 3 to the telephone line 2 side. Then, at time T4, the telephone line 2
Is detected by the reverse detection circuit 26, the CPU 10 determines that the other party has responded, and turns off the power supply control standby signal 15A. As a result, the loop closure is released by the line capture DP sending circuit 15, and a call is started with only the telephone line 2 and the telephone terminal 4 connected.

At a subsequent time T5, when the call is terminated and the loop current of the telephone line 2 is interrupted due to off-hook at the telephone terminal 4, this loop release is detected by the terminal loop detection circuit 13, and the terminal loop detection is performed. Signal 13A is OF
The state changes to the F state. At time T6, the CPU 10 confirms the on-hook state of the telephone terminal 4, that is, the unused state of the telephone line 2 according to the change of the terminal loop detection signal 13A, turns on the hook state information 10A, and starts the rapid charging operation. FIG. 4 is a flowchart showing the quick charging operation.

First, a quick charge timer for measuring the quick charge period t is started (step 41), and the quick charge signal 31A is controlled to an ON state (step 42). Note that the rapid charging period t is set to a period length that is not regarded as a loop closure on the exchange side, for example, about 100 ms or less. As a result, the transistor 31Q is turned on, and both ends of the high resistance 31R are short-circuited.
4, a large current (second current) at a high voltage when the telephone line is opened is supplied to the electrolytic capacitor 32 from the telephone line 2 to start rapid charging (step 43).

Then, it waits until the time of the quick charge timer expires (step 44), and controls the quick charge signal to the OFF state (step 45) according to the time up (step 44: YES). As a result, the transistor 31Q is turned off, a large current is cut off, rapid charging is stopped (step 46), and a series of operations ends. Thereafter, charging is performed with a small current (first current) via the high resistance 31R.

As described above, according to the present invention, in the charging circuit 31, in parallel with the high resistance 31R for charging the electrolytic capacitor 32 with a small current at a high voltage generated in the open telephone line 2, the high resistance 31R By providing a transistor 31Q whose both ends are short-circuited and turning on the transistor 31Q for a predetermined period t immediately after the telephone line 2 is opened, a current larger than the current on the high resistance 31R side is obtained from the telephone line 2 and the electrolytic capacitor 32 is connected. Charging. Thus, the high voltage voltage source V _B across the electrolytic capacitor 32, as compared to the case of starting charging only a high resistance 31R which is shown in dashed lines, increases in a short period of time.

In the above description, after the interruption of the loop current flowing through the telephone line 2 is detected, it is determined whether the state continues for a predetermined time or more in consideration of the hooking time and the like.
The case where the unused state of the telephone line 2 is confirmed to determine the start of the quick charging has been described. Instead of this loop current, the voltage at both ends of the telephone line 2 is monitored, and after a high voltage when the line is opened is detected, the unused state of the telephone line 2 is similarly determined by whether or not the state continues for a predetermined time or more. The start of quick charging may be determined by checking the state.

[0028]

As described above, according to the present invention, the first voltage which can be slightly obtained from the telephone line can be obtained.
And the capacitor is rapidly charged by obtaining a second current larger than the first current from the telephone line only for a predetermined period immediately after the opening of the telephone line. Can be charged in a short time. Therefore, even when the operating power charged in the capacitance element is consumed a lot when the telephone line is used, the operation can be quickly recovered to a certain extent and the stable operation can be obtained at the same time as the end of the telephone line.

[Brief description of the drawings]

FIG. 1 is a block diagram of a line selection device according to an embodiment of the present invention.

FIG. 2 is a circuit diagram illustrating a configuration example of a high-voltage power supply circuit of FIG. 1;

FIG. 3 is a timing chart showing the operation of FIG.

FIG. 4 is a flowchart showing a quick charging operation.

[Explanation of symbols]

1. Line selection device, 2. Phone line, 3. Terminal line, 4.
Telephone terminal, 10 CPU, 11 line relay, 12 terminal power supply circuit, 13 terminal loop detection circuit, 13A terminal loop detection signal, 14 diode bridge, 14A
Rectified output, 15: line capture DP transmission circuit, 15A: power supply control standby signal, 15B: line capture DP transmission signal,
15C: Loop closed output, 16: High impedance (H
I-Z) circuit, 17 ... electrolytic capacitor, 18 ... power supply circuit, 20 ... diode, 24 ... relay control circuit, 26 ...
Reverse detection circuit, 30 high-voltage power supply circuit, 31 charging circuit, 31R high resistance, 31Q transistor (switching means), 32 electrolytic capacitor (capacitance element), 3
3: Power supply control circuit, 34: diode, t: quick charging period.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masahiko Makino 2-3-2 Shimomeguro, Meguro-ku, Tokyo F-term in Tamura Electric Co., Ltd. (Reference) 5G003 AA08 BA01 DA04 GA01 GA10 GC05 5H030 AA03 AS11 BB01 DD20 FF42 FF52 5K027 EE16 GG02 GG08 JJ01 KK02 5K037 AA11 AB03 AC01 AC07 AD02 BA03 CA01 DA07

Claims (3)

[Claims] 1. A charging method for charging a power supply used in a device connected to a telephone line with a current obtained from the telephone line, comprising: a capacitive element for storing a high voltage generated in an open telephone line; A charging circuit for charging a capacitive element with a first current slightly obtained from the telephone line, wherein the charging circuit has a second current larger than the first current for a predetermined period immediately after the telephone line is opened. And charging the capacitive element rapidly by obtaining the current from the telephone line. 2. The line selection device according to claim 1, wherein the charging circuit includes a resistor element for obtaining a first current from the open telephone line, and a second element having both ends of the resistor element short-circuited. And a switching means for obtaining a current. 3. The line selection device according to claim 1, wherein the charging circuit rapidly charges for a predetermined period immediately after the unused state of the telephone line is confirmed after the loop current of the telephone line is cut off. Charging method.