CN2174730Y

CN2174730Y - Apparatus for obtaining stable d/c current from communication transmission line

Info

Publication number: CN2174730Y
Application number: CN 92242695
Authority: CN
Inventors: 谢国河
Original assignee: Individual
Current assignee: Individual
Priority date: 1992-12-19
Filing date: 1992-12-19
Publication date: 1994-08-17
Anticipated expiration: 2002-12-19

Abstract

The utility model relates to a device for obtaining stable direct current voltage from telecommunication transmission line, comprising a polarity protective circuit (1), low-pass circuits (2) and (3), an oscillating circuit (4), a coupling circuit (5), a rectifying filter circuit (6) and a voltage regulating circuit (7). Direct current voltage is obtained by the utility model and transformed into an alternate current signal and coupled through a transformer to the rectifying filter circuit and the voltage regulating circuit to be processed. The earth point of the output direct current power supply voltage are separated from the earth point of an original transmission system, thus the direct current voltage does not have crosstalk interference to the power supply of the associated circuit connected with the transmission sending. The electric voltage is highly stable and specially adapted to the telecommunication transmission system of large capacitance and high velocity.

Description

Apparatus for obtaining stable d/c current from communication transmission line

The utility model relates to a kind ofly obtains the device of stable DC voltage from telecommunications transmission lines, and this voltage is powered with incoming call interlock circuit that above-mentioned transmission line connects, and does not produce cross-talk.

In the telecommunication system, the direct supply voltage of presenting by transmission line is superimposed with all alternating signals such as voice, data.Existing obtain the Alternating Component that the method for above-mentioned supply voltage normally adopts this DC voltage of passive network filtering to superpose from transmission line, the earth point of gained DC voltage can not separate with the earth point of former transmission system, be easy to generate cross-talk, especially under the high situation of the big back of amount of transmission data speed, cross-talk is even more serious.

The purpose of this utility model is to solve the cross-talk that above-mentioned DC voltage feed is introduced, and by a kind of device that comprises active net, obtains direct supply voltage from transmission line, offers the interlock circuit use that this transmission system connects.

The utility model is to realize like this.

At first obtain DC voltage from the transmission line of telecommunication system with one group of active low-pass network and one group of passive low-pass network; The earth potential that is different from former transmission system for the earth potential that makes the gained DC voltage, to overcome the cross-talk that the public coupling of above-mentioned earth point causes, the AC signal that above-mentioned dc voltage conversion bunchiness is answered again, and through transformer coupled rectification, filtering circuit and the mu balanced circuit of arriving, above-mentioned AC signal is processed into required high stable DC voltage, exports to interlock circuit and do power supply.

The utility model has the advantages that:

1. can obtain the DC feedback of telecommunications transmission lines, and be processed into the output of high stability dc power supply voltage;

2. institute output DC source voltage earth point separates with former transmission system earth point, thereby can not produce cross-talk, and it is big to be specially adapted to current capacity, the telecommunication transmission systems that speed is high.

Below in conjunction with drawings and Examples the utility model is further described.

Fig. 1 is the utility model block scheme.

Fig. 2 is the utility model schematic diagram.

Be numbered in the accompanying drawing:

The 1-polar protective circuit, 2-low pass circuit, Q1, Q2-triode; R1, R2, R3-resistance, C1-electric capacity, 3-low pass circuit; C2-electric capacity, L1, L2-inductance, 4-oscillatory circuit, Q3-triode; the 5-coupled circuit, L3, L4-transformer coil, 6-current rectifying and wave filtering circuit; C4-electric capacity, D6-diode, 7-mu balanced circuit; the Q4-triode, the D7-Zener diode.

Embodiment: the utility model is made up of polar protective circuit 1, low pass circuit 2,3, oscillatory circuit 4, coupled circuit 5, current rectifying and wave filtering circuit 6, mu balanced circuit 7; as shown in Figure 2; polar protective circuit 1 LA that connects, LB are the two ends of communication system transmission line; (as the two ends of subscriber's line that telephone set connects); OUT is a dc voltage output end; VG2 is the earth point of original transmission system, and GND is other circuit ground ends that are different from VG2, and A, B, C, D represent potential point.Polar protective circuit 1 is made of four diodes, and it act as guarantees that the A point is a positive potential;

Low pass circuit 2 mainly is made of triode Q1, Q2, resistance R 1, R2, R3 and capacitor C 1, when A point signal is AC signal, the capacitive reactance of capacitor C 1 is almost nil, make the voltage of triode Q1 base stage be similar to triode Q2 emitter, triode Q1, not conducting of Q2, thereby the AC signal that A is ordered can not arrive the B point; Otherwise when A point signal was direct current, the capacitive reactance of capacitor C 1 was infinitely great, the DC voltage that A is ordered will be via the dividing potential drop of resistance R 1 and R2, and reach triode Q1 base stage, and and then starting triode Q1 and Q2, A point DC voltage is just passed through triode Q2 collector, emitter and is arrived the B point.Resistance R 3 is a high value.Be generally more than 1 megaohm, its effect is the interference of avoiding floating signal;

Low pass circuit 3 is made of inductance L 1, L2 and capacitor C 2, and its effect is further to intercept AC signal to arrive the C point, and direct current signal can arrive the C point;

Oscillatory circuit 4 is made of triode Q3 and inductance, electric capacity, and its effect is that C point direct current signal is become AC signal, and by transformer coupled to other circuit;

Coupled circuit 5 is made of transformer coil L1, L2, is used for AC signal is coupled to the D point;

Current rectifying and wave filtering circuit 6 mainly is made of diode D6 and capacitor C 4, and diode is used as rectification, and electric capacity is as filtering;

Mu balanced circuit 7 mainly is made of triode Q4 and Zener diode D7, and the stable DC voltage of its output terminal OUT is that Zener diode D7 voltage deducts triode Q4 base stage---0.6 volt of emitter forward voltage.

Claims

1, a kind of device of obtaining stable DC voltage from telecommunications transmission lines that relates to is used for to interlock circuit that above-mentioned transmission line connects power supply, and does not produce cross-talk; The utility model is made up of polar protective circuit (1), low pass circuit (2), (3), oscillatory circuit (4), coupled circuit (5), current rectifying and wave filtering circuit (6), mu balanced circuit (7), it is characterized in that:

Polar protective circuit (1) is used for guaranteeing that the A point is a positive potential;

Low pass circuit (2) is made of triode (Q1), (Q2), resistance (R1), (R2), (R3) and electric capacity (C1), when A point signal is AC signal, the capacitive reactance of electric capacity (C1) is almost nil, make the voltage of triode (Q1) base stage be similar to triode (Q2) emitter, triode (Q1), (Q2) not conducting, thereby the AC signal that A is ordered can not arrive the B point; Otherwise, when A point signal is direct current, the capacitive reactance of electric capacity (C1) is infinitely great, therefore, the DC voltage that A is ordered will be via resistance (R1) and dividing potential drop (R2), and reach triode (Q1) base stage, and and then starting triode (Q1) and (Q2), A point DC voltage is just passed through triode (Q2) collector, emitter and is arrived the B point; Resistance (R3) is high value, is generally more than 1 megaohm, and its effect is the interference of avoiding floating signal;

Low pass circuit (3) is made of inductance (L1), (L2) and electric capacity (C2), and its effect is further to intercept AC signal to arrive the C point, and direct current signal can arrive the C point;

Oscillatory circuit (4) is made of triode (Q3) and inductance, electric capacity, and it is used for the direct current signal that C is ordered is become AC signal, and by transformer coupled to other circuit;

Coupled circuit (5) is made of transformer coil (L1), (L2), and it is used for AC signal is coupled to the D point;

Current rectifying and wave filtering circuit (6) is made of diode (D6) and electric capacity (C4), and diode is used as rectification, and electric capacity is as filtering;

Mu balanced circuit (7) is made of triode (Q4) and Zener diode (D7), and the stable DC voltage of its output terminal (OUT) is that Zener diode (D7) voltage deducts 0.6 volt of triode (Q4) base-emitter forward voltage.