JPS59114989A - Feeding system - Google Patents

Abstract

PURPOSE:To reduce greatly the power consumption within a subscriber circuit by actuating a contact corresponding to a circuit which stores the subscriber lines at a short distance. CONSTITUTION:A subscriber circuit device LCU2 contains a 24V voltage source PW, relay contacts S1-S2m and a control circuit CU in addition to (n) units of subscriber circuits LC1-LC2m (m=n/2). The contacts S1-S2m connect circuits LC1-LC2m to a DC -48V power supply respectively in a recovery mode. Thus the DC -48V is used as the feed voltage. The operating states of contacts S1- S2m are separately controlled by the circuit CU. As a result, the power consumption within the circuit LC can be reduced down to half or so while maintaining a desired call current by actuating the contact S corresponding to the circuit LC which stores the subscriber lines at a short distance.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a device having a plurality of subscriber circuits, and more particularly to a power supply system for suppressing power consumption within the device.

(b) Prior art and problems FIG. 1 is a diagram showing an example of a subscriber circuit to which the present invention is applied, and FIG. It is a figure showing an example.

In FIG. 1, among the elements constituting the subscriber circuit LC, constant current circuits B1 and B2, a two-wire four-wire conversion circuit T, a balanced wiring network BN, an encoder COD, and a decoder DEC are shown. Constant current circuits B1 and B2 supply talking current from a -48 volt DC power source to the telephone device via the subscriber line. The communication current value increases or decreases depending on the distance of the subscriber line, but the upper limit is limited to a predetermined value, for example about 50 milliamps, by constant current circuits B1 and B2. As a result, if the subscriber line is very close, most of the power (approximately 2 watts) supplied from the DC -48 volt power source is wasted in the constant current circuits B1 and B2. In FIG. 2, n subscriber circuits LCI to LCn are provided within the subscriber circuit unit LCUI. Each subscriber circuit LC1 to LCn is all connected in parallel to a -48 volt DC power supply and uses -48 volt DC as the power supply voltage. Therefore, when a large number of subscriber circuits LC accommodating short-distance subscriber lines are included, the power consumption within the subscriber circuit LCUI increases and the amount of heat generated also increases.

(C) Purpose of the Invention The object of the present invention is to eliminate the drawbacks of the conventional power supply system as described above, and to reduce the power consumption in a device that includes a plurality of subscriber circuits that accommodate subscriber lines in extremely short distances. The goal is to realize a power supply system that saves as much electricity as possible.

(d) Structure of the Invention The object of the present invention is to provide a first means for generating a plurality of low voltages equally divided from a power supply voltage in an apparatus having a plurality of subscriber circuits equipped with a call current supply circuit with a current limiting function; a second means for switching the power supply voltage of each of the subscriber circuits from the power supply voltage to the low voltage; and a third means for controlling the second means so that the subscriber circuits are equally connected to each of the low voltages. This is achieved by providing the following means.

(e) Examples of the invention An embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 is a diagram showing a power supply system according to an embodiment of the present invention. Note that the same reference numerals refer to the same objects throughout the plan.

3rd rI! In J, subscriber circuit unit) LCUZ
n subscriber circuits LCI to LC2m (where m =
n/2), a 24V voltage source PW, relay contacts s1 to 32m, and a control circuit CU are provided. The 24V voltage source PW generates a low voltage (-24 volts DC) obtained by dividing the -48 volts DC power supply into three equal parts. Furthermore, when in the recovery state (the state shown in the figure), the relay contacts slb1 to s2m connect each of the subscriber circuits LCI to LC2m to a -48 volt DC power source, and use the -48 volt DC as the power supply voltage. On the other hand, when relay contacts s1 to s2m operate, m relay contacts s1, S3,...-52
m-1 is m subscriber circuits LCI, LC3, -L C2
m −1 are respectively connected between the output of the 24 V voltage source PW and the earth G, and m relay contacts s2.34,
...s2m is m subscriber circuits LC2, LC4,...
- The LC2m will be connected between the -48 volt DC power supply and the output of the 24 V voltage source pw, respectively, and -24 volt DC will be used as the power supply voltage. The operating state of each relay contact S (1 to s2m) is individually controlled by the control circuit CU. Therefore, the relay contact S corresponding to the subscriber circuit LC accommodating subscriber lines in the near i distance
, it is possible to reduce the power consumption in the subscriber circuit LC by approximately half while maintaining the required communication current. 24
The V voltage source pw is connected to the subscriber circuits LCI, LC3, . . .
The communication current flowing out from C2m-1 and the subscriber circuit L
C2, LC4, . . . , a current that is different from the communication current flowing into LC2m is supplied.

The control circuit CU stores in advance the subscriber circuit LC in the subscriber circuit unit I-LCU2 that accommodates short-distance subscriber lines, and the subscriber circuit LC is connected to the subscriber circuit LCI, L
C3, -L One circuit in C2m -1, subscriber circuit LC
2, LC4, . . . When it is determined that each circuit in LC2m is in a communication state, the corresponding relay contacts S are operated. As a result, the communication currents supplied from the 24V voltage source PW to both subscriber circuits LC are substantially canceled out, and even if a plurality of such paired subscriber circuits LC are generated, the 24V
The power consumption of voltage source PW becomes small.

As is clear from the above description, according to this embodiment, the power consumption of the subscriber circuit LC accommodating the short-distance subscriber line in the subscriber circuit unit LCU2 is reduced by approximately half, and The power consumption of PW is also minimal.

Note that FIG. 3 is only one embodiment of the present invention, and for example, the means for switching the subscriber circuits LCI to LC2m from a -48 volt DC power supply to a -24 volt DC power supply is a relay contact s.
1 to s2m, and many other modifications may be considered, such as realization by semiconductor switches S1a and slb to s2ma and S2mb as shown in FIG. The effect remains the same. Further, the power supply voltage and the low voltage are not limited to 148 volts and 124 volts, respectively, and many other modifications may be considered, but the effects of the present invention will not change in any case. Furthermore, it goes without saying that the device having a plurality of subscriber circuits LC is not limited to the subscriber circuit unit 1-LCU.

(fl) Effects of the Invention As described above, according to the present invention, the power consumption in a device including a plurality of subscriber circuits accommodating short-distance subscriber lines is significantly reduced, and the amount of heat generated is also reduced.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of a subscriber circuit to which the present invention is applied, FIG. 2 is a diagram showing an example of a conventional power feeding system, and FIG. 3 is a diagram showing a power feeding system according to an embodiment of the present invention. FIG. 4 is a diagram showing a power supply system according to another embodiment of the present invention. In the figure, LC is a subscriber circuit, L is a subscriber line, telephone is placed, B1 and B2 are constant current circuits, T is a 2-wire 4-wire conversion circuit, BN is a balanced wiring network, COD is a code circuit, and DEC is a decoding circuit. The circuits LCUI to LCU3 are subscriber circuit units, sl to s2m are relay contacts, and sla and slb to s2ma and s2mb are semiconductor switches. 2nd @

Claims (1)

[Claims] In an apparatus having a plurality of subscriber circuits equipped with a speech current supply circuit with a current limiting function, a first means for generating a plurality of low voltages equally divided from a power supply voltage; A second means for switching from the power supply voltage to the low voltage, and a third means for controlling the second means so that the subscriber circuit is equally connected to each of the low voltages. Power supply method.