CN2442310Y

CN2442310Y - Data communication interface device of passive telephone line

Info

Publication number: CN2442310Y
Application number: CN 00221842
Authority: CN
Inventors: 崔宪; 王文潇; 陈竹林
Original assignee: PLANNING AND DESIGN INST MAGANG (GROUP) HOLDING CO Ltd
Current assignee: PLANNING AND DESIGN INST MAGANG (GROUP) HOLDING CO Ltd
Priority date: 2000-09-21
Filing date: 2000-09-21
Publication date: 2001-08-08
Anticipated expiration: 2010-09-21

Abstract

The utility model relates to a data communication interface device of a passive telephone line, which comprises a PC communication interface circuit 1, a simulation off-hook circuit 2, a telephone communication interface circuit 3, a voltage stabilizing feed circuit 4 and a single chip computer data and signal processing circuit 5. Photoelectric isolation is used between the utility model and a computer. The computer controls the simulation hooking off, and the off-hook current of the telephone line is used for feeding electricity. As the utility model spares the power transformer, the audio transformer, etc. with large volume, and uses a photoelectric coupler to replace a relay to realize the simulation hooking off, the utility model has the advantages of compact structure, small volume, low cost, reliable work and high practicability.

Description

Passive telephone wire data communication interface device

The utility model relates to a kind of calling line number according to communication interface circuit.

In the prior art, the telephone wire data communication equipment (DCE) needs externally fed, and isolates with audio-frequency transformer (AFT), makes the one-piece construction more complicated, and volume-diminished is restricted.

The purpose of this utility model will provide a kind of volume little exactly, does not need externally fed, and the calling line number that does not use the audio-frequency transformer (AFT) isolation is according to communication interface.

The technical solution of the utility model is design like this: a kind of passive telephone wire data communication interface device, be characterized in: it comprises the PC communication interface circuit 1 with computer serial communication, simulation circuit for answering 2 by the computer control off-hook, finish the telephone communication interface circuit 3 of telephone wires signals transmission, on telephone wire, draw the voltage stabilizing power supplying circuit 4 of electric energy, realize the single-chip data and the signal processing circuit 5 of dialing automatically, data transmit-receive and data processing.

The utility model is simulated off-hook by computer control, from telephone wire draw+5V voltage and the electric current that is no more than 20mA power to whole device, and use photoelectrical coupler with computing machine and interface arrangement isolation.Because this scheme need not externally fed circuit and telephone wire buffer circuit, the bigger power transformer of volume and audio-frequency transformer (AFT) etc. have been saved, adding with photoelectrical coupler replaces relay to realize the simulation off-hook, make structure become particularly succinct, for dwindling of whole device volume provides advantageous conditions.

Fig. 1 is a circuit block diagram of the present utility model.

Fig. 2 is an embodiment circuit diagram of the present utility model.

The utility model is described in further detail below in conjunction with accompanying drawing.

In PC communication interface circuit 1, CZ1 is a computing machine RS-232 interface socket, wherein 1. pin is the request transmitting terminal RTS of computing machine, computing machine is by its control simulation off-hook, 2. pin is the transmission data terminal of computing machine, the serial data that interface arrangement is sent by its receiving computer, and 3. pin is the reception data terminal of computing machine, interface arrangement sends serial data by it to computing machine, and 4. pin is the signal ground of computing machine.Commutation diode D1 and electrochemical capacitor C1 form circuit for generating negative voltage, produce the 4. operating voltage of negative 9 volts of pin with respect to interface socket CZ1 the.Photoelectrical coupler G1 and resistance R 2, R3 form photoelectricity isolated data receiving circuit, send the RXD of single-chip data and signal processing circuit 5 to hold the serial data that computing machine is sent.Photoelectrical coupler G2 and resistance R 1, R4 form photoelectricity isolated data transtation mission circuit, and the TXD end data of single-chip data and signal processing circuit 5 is sent to computing machine.

In simulation circuit for answering 2, electrochemical capacitor C2 two ends have no-voltage to depend on the 1. pin of interface socket CZ1, the request transmitting terminal RTS of computing machine just, when RTS=1, electrochemical capacitor C2 charging, make photoelectrical coupler G3 conducting by resistance R 5, connect telephone communication interface circuit 3, realize the simulation off-hook.When RTS=0, electrochemical capacitor C2 discharge, photoelectrical coupler G3 turn-offs, and disconnects telephone communication interface circuit 3, realizes the simulation on-hook.

In telephone communication interface circuit 3, CZ2 is the telephone wire socket, and ZL1 is the polarity rectifier bridge, and triode T1, resistance R 6 are formed the signal transmitting and receiving circuit with capacitor C 3, C4.The fsk data signal that receives from telephone wire send the RXA of single-chip data and signal processing circuit 5 to hold by C3, and the fsk data signal of TXA end and dual-tone dialing signal send by telephone wire after capacitor C 4 couplings and triode T1 amplification in addition.

Working current behind the telephone wire off-hook, the emitter by triode T1 be electrochemical capacitor C5 charging in voltage stabilizing power supplying circuit 4, and through the serial regulating circuit voltage stabilizing that stabilivolt DW1 and luminotron LED1 form, provides+the 5V operating voltage to other circuit at last.The maximum operating currenbt that can provide depends on the off-hook working current of telephone wire, generally is not less than 20mA.Here LED1 is double does power supply indication.

Single-chip data and signal processing circuit 5 are made up of one-chip computer circuit, signal tone identification circuit, dual-tone dialing circuit and FSK modulation-demodulation circuit etc.It can finish the identification of signal tones such as dialing tone, busy tone, with the data communication of computing machine, and dual-tone automatic dialing, the transmission of fsk data and reception etc.

Claims

1, a kind of passive telephone wire data communication interface device, it is characterized in that: it comprises the PC communication interface circuit (1) with computer serial communication, simulation circuit for answering (2) by the computer control off-hook, finish the telephone communication interface circuit (3) of telephone wires signals transmission, on telephone wire, draw the voltage stabilizing power supplying circuit (4) of electric energy, realize the single-chip data and the signal processing circuit (5) of dialing automatically, data transmit-receive and data processing.

2, a kind of passive telephone wire data communication interface device according to claim 1 is characterized in that: described PC communication interface circuit (1) comprises the socket CZ1 that data transmit circuit that data receiver circuit that the circuit for generating negative voltage be made up of capacitor C 1 and diode D1, photoelectrical coupler G1 and resistance R 2, R3 form, photoelectrical coupler G2 and resistance R 1, R4 form and serial ports of computers connect.

3, a kind of passive telephone wire data communication interface device according to claim 1 and 2, it is characterized in that: described simulation circuit for answering (2) comprises capacitor C 2, resistance R 5 and photoelectrical coupler G3.

4, a kind of passive telephone wire data communication interface device according to claim 3, it is characterized in that: described telephone communication interface circuit (3) comprises rectifier bridge ZL1, triode T1, resistance R 6, capacitor C 3, C4 and the socket CZ2 that connects with telephone wire.

5, a kind of passive telephone wire data communication interface device according to claim 4, it is characterized in that: described voltage stabilizing power supplying circuit (4) comprises stabilivolt DW1, luminotron LED1 and capacitor C 5.

6, a kind of passive telephone wire data communication interface device according to claim 5, it is characterized in that: described simulation circuit for answering (2), telephone communication interface circuit (3) and voltage stabilizing power supplying circuit (4) are connected in series with respect to the working current of telephone wire.