JPS5848559A - Supplying system for call current - Google Patents

Abstract

PURPOSE:To prevent sudden change of a call current, by controlling a time average value of a call current supplied to a terminal device of a telephone exchanger so as to close to a reference current. CONSTITUTION:A call current is supplied to a subscriber line 1000 via a smoothing circuit from a DC power supply 100 and to a terminal device 300. A call current detecting circuit 200 detects a voltage across a resistor 201 connected between a switching power supply circuit 110 and the terminal device 300 and gives a DC voltage in response to the call current value to an operation circuit 400. The integration operation circuit 400 integrates an output voltage from the circuit 200 and calculates a time average of the call current value. A comparison circuit 600 compares this average value with an output voltage of a reference voltage generating circuit 500 and gives a control signal to the switching circuit 110 so as to close the averaged value to the reference voltage.

Description

[Detailed description of the invention] The present invention relates to a communication current supply system for a telephone exchange.

Conventional switching control type communication current supply circuits have a fixed supply current value, which lacks flexibility, and they also react excessively to dial pulses, etc., resulting in sudden changes in the current, making stable communication difficult. Cannot supply current.

The purpose of the present invention is to obtain the temporal average value of the communication current supplied to the terminal equipment of the telephone exchange (subscriber telephone, relay connection device), and to control this value so that it approaches a preset reference current value. By.

To provide a communication current supply system that can prevent sudden changes in communication current and also allows arbitrary changes in the setting basis of communication current by configuring a program control type control means. be.

The communication current supply method according to the present invention compares the average value of the communication current obtained from the feedback information of the communication current supplied to the terminal equipment of the telephone exchange with a preset reference value of the communication current, and determines the power supply drive signal. It is characterized by comprising a communication current control means that performs pulse width control. Preferably, the communication current control means is configured to be able to arbitrarily change the reference value of the communication current by program control.

Further, the above-mentioned communication current control means identifies the overcurrent supply state from the feedback information of the communication current, and the stain source drive signal is stopped by the overcurrent feedback regardless of the control of the communication current side control means. t-Characterized.

Embodiments of the present invention will be described below with reference to FIG. 1 iii.

FIG. 1 is a block diagram showing a first embodiment of a communication current supply system according to the present invention.

In the same figure, one round current is a DC power supply 100), a switching transistor 101, a diode 1o2. The subscriber terminal vhi is connected to the subscriber line 1000 via a smoothing circuit composed of a coil 103 and a capacitor 104.
ooc supplied. Communication current supply system wI20 (l DC° power supply 100, switching transistor 101. and switching power supply circuit 11G consisting of the above-mentioned smoothing circuit
Tlcl! and subscriber terminal 11300. Continued gtL&
The voltage generated across the lna resistor 1) 20110 is detected by the operational amplifier 202, and a DC voltage corresponding to the DC current capacity of the resistor 201 K1 is applied to the communication current value information (feedback information) integration calculation circuit 400. The integral calculation circuit 400 is constituted by an operational amplifier 401, a resistor 4.02, and a capacitor 403. It receives the communication type fil information given by the communication current cage detection circuit 200, and calculates the resistance value 8 of the resistor 402.
Then, the communication current value information is integrated according to a time constant (rCR) determined by the capacitance fIiC of the capacitor 403. The integration result here is sent to the comparator@6004C as the average value of the communication current from the start of the communication current supply to the present time. Further, the reference voltage generation circuit 500 includes a DC power supply 501 and a resistor 502-.

503 generates a reference voltage corresponding to the set value of one call current and supplies it to the comparator circuit 600.

The comparison circuit 600 compares the reference voltage from the reference voltage generation circuit 500 and the average value of the speech current which is the output of the integral calculation circuit 400. A control voltage that increases the current for one conversation is output to the comparator 701, and a control voltage that decreases the current for one conversation is output to the comparator 701 when the voltage is higher than the set value.
Output to.

A comparison 11701 compares the control voltage from the comparison circuit 60G and the output of the sawtooth wave generation circuit 702. Comparison 57ot
The input/output voltage relationship of the switching transistor drive circuit 760 is shown in FIG.
In the process of supplying communication current to subscriber terminal 5aoo by driving 01, if the average value of one communication current is smaller than the set value, the comparator circuit 600
and the comparator 701] by increasing the pulse width (Pw) of the rectangular wave voltage formed by the switching transistor 10.
The conduction ratio of 1 is increased to increase the communication current. On the other hand, if the average value of the five communication currents is larger than that of the first setting, the pulse width is made small to reduce the conduction ratio of the transistor 101 and reduce the communication current rItt-.

In this way, the integral calculation circuit 4Q() calculates the average call current 1i1 and compares it with the set value to calculate the switching power supply circuit 110@: drive control L subscriber terminal equipment 3
It is possible to supply a communication current that responds slowly to a change in the state of 00.

FIG. 3 is a block diagram showing a second embodiment of the present invention.

The communication current supply in this embodiment is performed in the same manner as in the first embodiment described above, but the communication current value detection circuit 21
1 is operational amplification i! 1212 and resistors 213 and 214, and the subscriber terminal equipment 3001 of the resistor 210
The communication current value is detected by the voltage generated at 8, and the black-pressure which is compared to the current-output value is output to the integrating circuit 410. The fR branch circuit 410 is composed of a resistor f411 and a capacitor 412, and has a resistance value of 8. Furthermore, it has a time constant of 10R, assuming that the capacitance of the capacitor is C, performs temporal integration on the input voltage, and outputs the result. When focusing on a certain point in time, this output changes the call type up to that point. Here, the comparison circuit 600 is similar to the comparison circuit 600 in FIG. Further, the program control means 800 stores the setting value of the communication current in the form of a digital code.

This digital code is stored in buffer register 510 by a strobe signal on strobe signal line 802 via data signal line 801t. The digital/analog conversion circuit 511 receives the digital code corresponding to the setting @ of the communication current stored in the buffer register 510, converts this code into digital/analog, and compares the analog voltage level corresponding to the setting value of the communication current with the comparison circuit 600. give to Note that the switching power supply drive circuit 710 is the comparator 701. in FIG. It operates the sawtooth wave generating circuit 702° and the filtering transistor driving circuit 70G.

In this second embodiment, 7 go during program control.

By changing the digital code corresponding to the setting basket of the communication current stored in K by a program, it is also possible to arbitrarily and variably set the communication current supply value.

FIG. 4 is a block diagram showing a third embodiment of the present invention.

In the figure, the communication current (detection circuit 220 performs the same operation as the resistor 210 and communication current value detection circuit 211 in FIG. 3) is omitted, and the reference voltage generation circuit 500 is the reference voltage generation circuit in FIG. It is similar to 500.5th
The detailed configuration of the logic calculation circuit 421 is shown in the figure, and the temporal relationship of each signal in the logic calculation unit 460 is shown in FIG. Hereinafter, when the third embodiment is concretely established with reference to FIGS. 4, 5, and 6, the logic operation DO
431 in the path 421 is a first buffer register, 432
a@2 buffer register and 43n Id, nth
This is a buffer register for the clock signal generation circuit 42.
3] respectively strobe signal lines 441, 442...
It receives a strobe signal via 441. The analog/digital conversion circuit 420 receives the analog input from the speech current value detection circuit 220 and converts the analog input corresponding to the nine speech current cages into a digital code and outputs the digital code. Buffer register 431
゜432...43nF1 Kurotsudori signal generation circuit 42
The strobe signals are received from 3 at a period of io.

t.

Each strobe signal 15 is sequentially applied to the buffer register 431 at the same time with a time difference of 15, and each buffer register temporarily stores the digitally encoded communication current value by this strobe signal. The outputs of the buffer registers 431 to 43111 are added by an adder circuit 450 and further multiplied by 1/n by an n divider circuit 451. That is, the average value of n communication current values every hour to/n is calculated. This average value is determined by the strobe signal on the strobe signal line 453 in the buffer register 45.
2 is temporarily stored. The information stored in the buffer register 452 changes every time to/n, and each piece of information is the average of digitally encoded n call current values extracted every Kto/n time within to time up to the point in time. It is a value. The output of buffer register 452 is a digital
The time relationship of the 0 or more operations converted to an analog voltage level by the analog conversion circuit 422 and provided to the comparator *600 as an average value of one call current is clearly shown in FIG.

In this manner, the third embodiment converts the communication current value into a digital code, obtains the average value within a certain period of time, and controls the switching power supply circuit 110 based on this average value. It is possible to bring the communication current value closer to the set value.

FIG. 7 is a configuration diagram showing a fourth embodiment of the present invention.

” In the same figure, the same circuits as in each of the above-described embodiments are indicated by the same symbols.The communication current value is converted by the detection circuit 200 into an analog voltage level corresponding to the current fi, and further analog-to-digital conversion is performed. digitally encoded by circuit 230].

The program control means 900 periodically reads the digital code corresponding to the communication current value every time tl and stores it in the internal memory. Furthermore, the average value of the latest n of the digital code 1-hi call current values accumulated every 11 hours is calculated, and this average value is combined with the preset and stored set value of the one-talk current. compare. In the comparison result, if the flat bird value is smaller than the set value, the comparison circuit 90
For 2, a value smaller than the previous 7 (it time ago) is given as control information as a digital code, and on the other hand, if the average value is larger than the set value, a value larger than the previous value is given as control information. Give as information. Comparison circuit 902 is 0 to R
The counting information received by the counting circuit 901, which repeats counting at 1, is compared with the control information.

If the count information is equal to or smaller than the control information, a logic low level signal is output, and if the count information is greater than the control information, a logic high level signal is output. These outputs are sent to switching transistor drive circuit 700 as square wave voltage signals. Here, the period of the rectangular wave voltage signal is equal to the time taken by the counting circuit 901 to count from 0 to R1.

The time ratio between high level and low level is determined by the above control information. That is, the program control means 900 controls the communication current a
t-periodically read] Calculate the average of n reading values, and if this average value is smaller than the set value of the talking current,
A smaller value is given to the comparator circuit 902, and the comparator circuit 902 increases the high level time of the output square wave to the subscriber terminal station.

Increase the call current to. On the other hand, if the above average value is larger than the set value, a larger value is given to the comparator circuit 902 to reduce the high level time of the rectangular wave, thereby reducing the communication current. can supply a talking current of . It was. The operation of the program control means 900 can be arbitrarily set by changing the program.
Flexibility, such as changing the supply current to an arbitrary value and sending control information after a certain period of time after taking the call current value, makes it unresponsive to dial pulses received from the subscriber terminal equipment 300. A certain communication current supply can be achieved.

FIG. 8 is a block diagram showing a fifth implementation IFIJt of the present invention.

In the same figure, the 1-communication current value detection circuit 240 functions as the communication current value detection circuit 200 and the analog-to-digital conversion circuit 230 in FIG.
, t- has a function of sending overcurrent information, which is a logic signal, to the overcurrent information signal line 241 when detected. Also,
The switching power supply drive circuit 740 has a function of reading the above-mentioned overcurrent information in addition to the functions of the counting circuit 901 and the comparison circuit 902 in FIG. Furthermore, the program control means 940 has the functions of the program control means 900 in FIG. 7 and the function of reading overcurrent information.

In this embodiment, when the switching power supply drive circuit 740 receives the above-mentioned overcurrent information, the program control means 940
It immediately outputs a logic low level and stops the current supply regardless of the control information received from the circuit. damage can be prevented. Furthermore, the program control means 940 controls the switching power supply based on the above-mentioned overcurrent information.

Stopping or controlling the stain flow supply by sending a sufficiently large number (I[) to drive circuit 740.

The above explanation is a trap.As is clear, according to the original F14, 1
It is necessary to control the talking current so that the temporal average value approaches a preset reference current value.This is to prevent sudden changes in the talking current.LThis talking current value control is controlled by a program. (Setting) It is possible to create a communication current supply whose value can be changed arbitrarily. It is also possible to add optional wax flow supply functions such as overcurrent detection.

[Brief explanation of the drawing]

1 is a block diagram showing a first embodiment of the communication current supply system according to the present invention; ・FIG. 2 is a diagram showing input/output signal waveforms of the comparator of the switching power supply drive circuit in FIG. 1;
FIG. 4 is a block diagram showing a second embodiment of the present invention, FIG. 4 is a block diagram showing a third embodiment of the present invention, FIG. 5 is an enlarged block diagram showing details of the logic operation section in FIG. FIG. 6 is an explanatory diagram of the operation of the logic calculation section, FIG. 7 is a block diagram showing a fourth embodiment of the present invention, and FIG. 8 is a block diagram showing a fifth embodiment of the present invention. . 110...Switching power supply circuit, 200゜2
11.220,240-Song/talk current value detection circuit, 23
0...Analog-digital conversion circuit, 300
...cut entry terminal, 400...integral calculation circuit, 416...integration circuit, 420...
・Analog-digital conversion circuit. 421...Logic operation circuit% 422...
・Digital/analog conversion circuit, 423...
Clock signal generation circuit, 500...Reference voltage generation circuit%510...Buffer register, 511
・・・・・・Digital/analog conversion circuit, 600・
... Comparison circuit, 700 ... Switching transistor drive circuit, 701 ... Comparator %
710, 740... Switching power supply drive circuit, 800, 900, 940... Program control means, 901... Counting circuit, 902...
・Comparator. K Phase-W Eyebrow-Chito

Claims (2)

[Claims] (1) Control the pulse width of the power supply drive signal by comparing the average value of the passing current obtained from the feedback information of the passing current supplied to the terminal equipment of the telephone exchange with a preset reference value of the passing current. A telephone current supply system characterized by comprising a telephone current control means. (2) The communication current control means performs overcurrent identification based on feedback information of the communication current, and the power supply drive signal is stopped by the overcurrent feedback information regardless of control by the control means. A communication current supply system according to claim 1.