CN2057541U - Line-concentrating volume-enlarging telephone exchanger - Google Patents

Abstract

The utility model discloses a line-concentrating volume-enlarging telephone exchange, which is composed of a microcomputer control circuit, an output interface and driving circuit, a relay matrix, an input interface circuit, an internal and external lines state recognizer, a peak voice generator, a ringing generator and a power source. The utility model is characterized in that the internal and external lines state recognizer comprises an external line state recognizer and an internal wire state recognizer, and the external line state recognizer comprises an external line dial-up signal recognizer and an external line ringing recognizer. The exchange concentrates the advantages of private branch exchanges and subscriber concentrators, improving the traffic index without increasing the local subscriber lines and occupying local numbers. The utility model is suitable to be used in office buildings and places with busy local lines and a large number of subscribers.

Description

Line-concentrating volume-enlarging telephone exchanger

The utility model relates to telephone exchange, a kind of line concentration dilatation telephone exchange.

Telephone is as the important means of communication, use more and more widely in China town and country, but because the installed capacity of each department phone is limited, the circuit anxiety, can not satisfy the demand of society far away, and carry out investment for trnasforming urban land on a large scale and still have any problem, therefore, adopt small switch to alleviate above-mentioned contradiction mostly.

There is following problem in employed most of switches at present: the one, and the direct dialing in incoming call needs post and telecommunications office that trunk rather than general link circuit are provided, and therefore need increase the line facility investment at local side.For this reason, the switch arrangement operator who has is on duty, increases operator on duty and communication security problem.The 2nd, the extension set under the switch can only just can be gone in the local network by And after dialling " 0 ", and this just makes troubles to the user.The 3rd, general switch is equipped with inner cord circuit, during internal communication, can only dial extension number, and this needs the user to understand oneself and the other side to be inside line ， And and need to understand the different dial-up of memory number, caused another trouble to the user.

Task of the present utility model is intended to address the above problem, and proposes a kind of novel switch that can use general link circuit to realize the direct dialing call-in and call-out functions.

The utility model telephone exchange, by microcomputer control circuit, output interface and drive circuit, relay matrix, input interface circuit, internal and external line state identifier, buzzer generator, ringing current generator and power supply are formed.Microcomputer controlled electro route central processing unit (CPU), program storage (EPROM), latch and anti-clutter circuit are formed; Output interface circuit and drive circuit are made up of D-latch, decoder and drive circuit; Input interface circuit is a tristate buffer.It is characterized in that the internal and external line state identifier comprises external line state identifier and interior lines state identifier, the external line state identifier comprises outside line dial-up signal identifier and outside line ringing-current identifier, outside line dial-up signal identifier is by the dummy load circuit, full-wave rectifying circuit, low pass filter, photoelectrical coupler and filter are formed, outside line ringing-current identifier is isolated by outside line, photoelectrical coupler, amplifying circuit, monostable circuit and gated circuit are formed, and the interior lines state identifier is by the voltage stabilizing didoe box-bit circuit, low pass filter, photoelectrical coupler and filter circuit are formed.

Detailed technology content of the present utility model reaches accompanying drawing in conjunction with the embodiments and is further specified.

Fig. 1 is an embodiment circuit The general frame.

Fig. 2 is the block diagram of embodiment microcomputer control circuit part.

Fig. 3 is the block diagram of embodiment output interface circuit and drive circuit thereof.

Fig. 4 is the circuit block diagram and the circuit theory diagrams of outside line dial-up signal identifier, and wherein Fig. 4 .1 is a circuit block diagram, and Fig. 4 .2 is circuit theory diagrams.

Fig. 5 is the circuit block diagram and the circuit theory diagrams of outside line ringing-current identifier, and wherein Fig. 5 .1 is a circuit block diagram, and Fig. 5 .2 is circuit theory diagrams.

Fig. 6 is the circuit block diagram and the circuit theory diagrams of interior lines state identifier, and wherein Fig. 6 .1 is a circuit block diagram, and Fig. 6 .2 is circuit theory diagrams.

Fig. 7 is the dial circuit theory diagrams.

Fig. 8 is the relay matrix circuit theory diagrams.

Fig. 9 is electric principle schematic.

Present embodiment is program control 2/8 line concentration dilatation telephone exchange, this function is opened eight extension subscribers in two pairs of outside lines (local user's line), eight extension set inside can exchange by a cord circuit, use this function not increasing local user's line, do not take the Local Number, improve the affair figureofmerit of living.Present embodiment mainly is made up of microcomputer control circuit, output interface and drive circuit, relay matrix, input interface circuit, internal and external line state identifier, buzzer generator, ringing current generator and power supply.

Microcomputer control circuit comprises central processing unit (CPU), program storage (EPROM), latch and anti-clutter circuit, these circuit are mixed corresponding program, be used to explain each state variation of switch, and, be that index request designs according to the telephone exchange behavior in different situations.CPU (central processing unit) is carried out and is for example transmitted data, changes functions such as data and enforcement of judgment execute a judgement, the 80C39 chip that present embodiment selects for use Japan to produce.Program storage is used to deposit working procedure, during microcomputer work, provides course of work instruction by it, and present embodiment is selected EPROM27C32 for use.Latch is used for the latching of address signal on the data/address bus BUS, and present embodiment is selected 8D latch 74HC373 high-speed cmos 8D flip-flop circuit for use.Anti-clutter circuit plays the hardware self-healing, and the anti-clutter circuit of present embodiment is made of two monostable multichannel tuned oscillators (CD4098).

Output interface circuit and drive circuit thereof comprise D-latch, decoder and drive circuit.D-latch latchs as data bus signal output, and present embodiment adopts 4 d latch CD4042, and decoder adopts BCD-to-decimal decoder CD4028, and drive circuit adopts MC1413.

Input interface circuit is a tristate buffer, is used as the external signal input buffering in circuit, and present embodiment is selected 6 tristate buffer CD4503 for use.

The internal and external line state identifier comprises external line state identifier and interior lines state identifier, and these two parts constitute the test section.The external line state identifier comprises outside line dial-up signal identifier and outside line ringing-current identifier.Outside line dial-up signal identifier is used for " very ", " puppet " of microcomputer identification outside line signal, it is the key that the exchange function realizes the direct dialing incoming call, present embodiment is made up of dummy load circuit, full-wave rectifying circuit, low pass filter, photoelectrical coupler and filter, and Fig. 4 .2 has shown the physical circuit schematic diagram.Outside line ringing-current identifier is the ring situation after the judgement outside line incoming call, is used for after the dialing of microcomputer recognition machine is " very " state, and the user sends ring-back tone to outside line.Present embodiment is made up of outside line buffer circuit, photoelectricity coupling circuit, amplifying circuit, monostable circuit and gated circuit, and Fig. 5 .2 shows its physical circuit schematic diagram.The interior lines state identifier is used to reflect whether state such as off-hook, on-hook, ringing-current, dialing of user, present embodiment is made up of voltage stabilizing didoe clamp circuit, low pass filter, photoelectrical coupler and filter circuit, and Fig. 6 .2 shows its physical circuit schematic diagram.

Relay matrix is made of relay, a relay all is set on formed each crosspoint between horizontal line and the vertical line, present embodiment is by eight of inner phones, two of outside phones, they all are connected in the matrixing network, have 50 relays in the network, all controlled circuit control of each relay is carried out.The conversion portion of this machine all is to carry out control relay by mainframe program by data/address bus to carry out.

Buzzer generator constitutes the pulse oscillation circuit of 450Hz by the CD4069 chip, passes through the isolation of power amplification and output transformer again, realizes ring-back tone, dialing tone and busy tone by buzzer relay control.

The ringing-current transmitter is made up of ringing current generator and control contact, and ringing current generator is by the signal of 25 He Zhi oscillating circuits through 25 He Zhi of one 60 volts of amplifying circuit generations, and the output of ringing-current is realized by host computer control.Buzzer generator and ringing current generator are familiar technology, are not described in detail here.

The outside line key of this machine can directly deposit EPROM inside in, user's use of installing for convenience, also can on microcomputer control circuit, increase the dial circuit, the dial circuit is made up of BCD dial and scan-data memory, tristate buffer and switching diode, resistance etc., mainly in order to determine the dialing feature of this switch, adopt the dial circuit can discern dialing and whether belong to internal user, thereby alleviate the telephone traffic burden of outside line.

For the user that need carry out multi-metering to local telephone network, can on former microcomputer control circuit, increase the multi-metering display, reach the function of multi-metering, the multi-metering display adopts general electromagnetic type pulse counter.

The utility model course of work brief description is as follows:

The inner phone of external call: when outside phone is called out this switch number, just by exchange to this switch ringing-signal feeding, bell signal is by outside ringing-current identifier, produce a request pulse, deliver to middle fracture, processor will respond this interrupt requests, interrupt routine is handled dummy load is connected the outside line cord circuit, make the outside be in off hook state, and open the external signal identifier, wait for receiving last dial-up signal of caller.After last dial-up is finished, just can determine that outside phone will call out that inner phone, processor is just inquired about the immediate status of this telephone set from machine account, if this phone is in answer, then send busy tone, if this phone is in hook state (having time) to the outside line phone, then send ring-back tone to the outside line phone, called phone send the ringing-current ring, answers until called off-hook, till the two is connected.

Inner phone is called out inner phone: when internal user was called out internal user, processor will detect this calling by detecting mouth, and at ordinary times, processor is that periodically (every 1ms) reads state of user.For example, when an internal user will be called out, when being in off hook state, by inside knowledge portion circuit, its signal becomes level"1" from level "0", and processor just has been construed to the customer requirements call, for this reason, processor has been remembered its previous state situation, but with regard to this state status of respective handling, after having dialled telephone code, processor is through discriminant analysis, is it interior lines that dial-up requires, or outside line, and inquiry machine account cord circuit is free? carrying out control corresponding handles.

In sum, the utility model has been concentrated the advantage of Private Branch Exchange PBX and Subscriber Line Concentrator, can not increase local user's line, do not take the Local Number, improve the telephone traffic index, have the advantages such as volume is little, low in energy consumption, easy to maintenance thereby save a large amount of track investment ， And. Be applicable to the many places of the nervous user of suburb, residential area, office block and local line.

Claims (3)

1, a kind of line concentration dilatation telephone exchange, by microcomputer control circuit, output interface and drive circuit, relay matrix, input interface circuit, the internal and external line state identifier, buzzer generator, ringing current generator and power supply are formed, it is characterized in that: the internal and external line state identifier comprises external line state identifier and interior lines state identifier, the external line state identifier comprises outside line dial-up signal identifier and outside line ringing-current identifier, outside line dial-up signal identifier is by the dummy load circuit, full-wave rectifying circuit, low pass filter, photoelectrical coupler and filter are formed, outside line ringing-current identifier is by the outside line buffer circuit, the photoelectricity coupling circuit, amplifying circuit, monostable circuit and gated circuit are formed, and the interior lines state identifier is by the voltage stabilizing didoe clamp circuit, low pass filter, photoelectrical coupler and filter circuit are formed.

2, telephone exchange according to claim 1 is characterized in that microcomputer control circuit is connected to the dial circuit, and this circuit is made up of binary-coded decimal dial and scan-data latch, tristate buffer and switching diode.

3, telephone exchange according to claim 1 and 2 is characterized in that microcomputer control circuit is connected to the multi-metering display, and compound count display adopts universal electromagnetic formula pulse counter.

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