CN2208301Y

CN2208301Y - Special telephone

Info

Publication number: CN2208301Y
Application number: CN 94229932
Authority: CN
Inventors: 冯朝敦
Original assignee: Electronic Equipment Factory Shuxin Science And Technology Combination Co Sic
Current assignee: Electronic Equipment Factory Shuxin Science And Technology Combination Co Sic
Priority date: 1994-12-01
Filing date: 1994-12-01
Publication date: 1995-09-20
Anticipated expiration: 2004-12-01

Abstract

The utility model relates to a special telephone with a program control function, which comprises a signal emitting circuit composed of a coding circuit, a decoding circuit, an audio frequency amplifying circuit, a power amplifying circuit, a ringing circuit and a busy tone circuit, a signal receiving circuit and a control circuit, etc. The utility model has the advantages that the digital tone dialing is reliable, the ringing time is delayed and automatically controlled to a setting time, the functions of a dialing tone, echo, busy tone (busy tone), and group call are complete, the duplex conversation voice is clear, and transmission distance can reach 50 to 100 km.

Description

Special telephone

The utility model relates to a kind of communication telephone set, and it is particularly related to a kind of special service telephone set with programmable function.

The prior art situation is, general telephone set is made up of the parts of coding, ring, amplification and other additional function, and it has general encoding function, and decoding function is realized by the program control exchange of local telephone network.This technology only is useful for the fixing occasion of conversation object, it is characterized in that telephone set can not be carried out long-distance transmissions with the programme-controlled unit that separates, and can only amplify, transmit by middle, just may carry out long-distance transmissions.Through new to looking into of Chinese patent database and electronics, post and telecommunications publication, not finding does not have similar techniques to apply for a patent, and does not have similar techniques to carry out open report and publication yet.

The purpose of this utility model is to propose a kind of button special service telephone set with perfect transmission, reception, coding, decoding, selective call function, makes it to integrate program control and function telephone set, and can carry out the communication of 50-100 kilometer.

The purpose of this utility model can realize by following technical measures.

This special service telephone set, it comprises that the signal sending circuit and signal receiving circuit and the control circuit etc. that are made of coding circuit, decoding circuit, audio amplifier circuit, power amplification circuit, ringing circuit, busy tone circuit form, it is characterized in that in the signal sending circuit part, the output of coding circuit links to each other with the input of power amplification circuit, input with power amplification circuit after voice signal amplifies through pre-amplification circuit links to each other, the output of power amplification circuit links to each other with the input of step-up transformer B1, the output output boost signal of transformer B1.In the signal receiving circuit part, input with decoding circuit after the signal one tunnel that circuit is sent here amplifies through another pre-amplification circuit links to each other, the output of decoding circuit links to each other with the input of decimal system change-over circuit, and an end of change-over circuit links to each other with circuits for triggering and ring back tone circuit with time-delay control through behind locking circuits for triggering and the level shifting circuit; One output of locking circuits for triggering links to each other with the input of control circuit; Another road of the signal that circuit is sent here links to each other with audio frequency reception, amplifying circuit.In the control circuit part, two outputs of control circuit link to each other with busy tone generation circuit with dialing tone generation circuit respectively, and another output of control circuit links to each other with the big circuit of audio interface retractable of signal receiving circuit.

Specific implementation technology of the present utility model is: the parts of signal sending circuit are to become decoding circuit by integrated circuit (IC) 7 be attached thereto the button that connects etc. and form, the 7-8 pin of IC7 meets crystal oscillator JX1, and code signal links to each other with the base stage of the transistor BG9 of pre-amplification circuit with resistance W1 by capacitor C 23; Transistor amplifier circuit BG10, the BG9 that front end circuit is amplified by two-stage and be attached thereto the capacitor C 34-C39, the resistance R 42-R47 that connect and form, wherein, BG9 is an emitter output circuit, to reduce the input impedance of power amplifier, the output of Mike MC1 is continuous with the base stage of BG10 through capacitor C 35, the other end ground connection of MC1 (negative pole of power supply); Power amplification circuit is made up of power amplification circuit IC9 and the capacitor C 40-C42 that is attached thereto thereof and resistance R 49 and R52, the signal of BG9 emitter-base bandgap grading output links to each other by the input of capacitor C 39 with IC9, link with the elementary of transformer B1 by capacitor C 42 power output signals, the contact of the elementary other end by K switch 5 through loud speaker Y2 after ground connection, output voltage passes through K switch 1 to line output signal through secondary the boosting of transformer B1 after.

Signal receiving circuit of the present utility model is to link to each other by the input of capacitor C 6 with the integrated circuit (IC) 1 with strong automatic gain control, also be connected with capacitor C 1-C11 and resistance R 1-R6 on the IC1, resistance R 5, R6 and diode D1, capacitor C 8 constitute automatic gain control circuit, make the output voltage of IC1 keep constant in certain scope, IC1 is by capacitor C 11, C13 and resistance R 8 output voltage signals; Decoder ic IC2 and the resistance R 8-R10 that is attached thereto, crystal oscillator JX1 and capacitor C 15 are formed decoding circuit, signal after decoding circuit is deciphered by the 11-14 pin output of IC2 is also respectively with 10 of decimal system change-over circuit IC3,13,12,11 pin link to each other, the output pin 1-7 of IC3,9,14, gating signal after the 15 output conversions triggers integrated circuit (IC) 4 to locking, 3 pin of IC4 link to each other with 3 pin of IC3,7 of IC4,11,15 pin can link to each other according to the arbitrary output pin of coding needs with IC3, constitute the specific coding of this machine, this machine of gating in this way, IC4 outputs signal to the base stage of the BG1 of level shifting circuit by diode D4, and the collector electrode output triggering signal by BG2 is given input 2 pin of integrated circuit (IC) 5 after BG1 and BG2 amplification, be connected with capacitor C 17-C19 and resistance R 19-R22 on the IC5, time-delay control links to each other with the base stage of triggering signal through resistance R 22 allomeric pipe BG3, on the collector electrode of BG3, be connected with the winding of relay J 1, the other end of J1 winding links to each other the grounded emitter of BG3 with the positive pole of power supply; The end of one group of contact J1B of relay J 1 links to each other with the positive pole of power supply, and the other end links to each other with the collector electrode of the transistor BG4 of the feeder ear of ring back tone integrated circuit (IC) 11 and amplification output circuit, and continuous with an end of button 8 by diode D7, D19; Be connected with the amplifying circuit that ring integrated circuit (IC) 11 and transistor BG4, BG5 constitute on the positive pole of D7, bell signal is exported an end that connects loud speaker through the collector electrode of BG5, and the other end of loud speaker Y3 links to each other with the positive pole of D7; The end of another contact J1A of relay J 1 links to each other with the output of integrated regulator IC12, and the other end links to each other with 6 pin of integrated circuit (IC) 4 by diode D5, also passes through diode D6 on this end with integrated circuit (IC) 3; 5 pin link to each other to form lock-in circuit; The power supply circuits that also connect integrated circuit (IC) 1, IC2, IC3, IC4, IC8 on the output of integrated regulator IC12; Audio amplifier circuit is the audio signal that circuit transmits, by the contact J2A of control circuit, the effect of J4A, to link to each other by the input of capacitor C 31 through the audio signal after resistance R 38, the R39 dividing potential drop with integrated circuit (IC) 6, with IC6 link to each other also have capacitor C 26-C31, C49 and, IC6 gives earphone Y1 by capacitor C 27 output audio signals, and resistance R 37 is short range damping resistances.

Control circuit of the present utility model is that a NAND gate input of integrated circuit (IC) 8 is continuous with an output 2 pin of integrated circuit (IC) 4, after another group NAND gate circuit of signal process IC8 is anti-phase, base stage through resistance R 28 allomeric pipe BG7 links to each other, and after transistor BG6 amplifies control relay J2, one end of the electromagnetism winding of J2 links to each other the other end ground connection of winding with the collector electrode of BG6; Two groups of NAND gate circuit in addition of IC8 constitute an oscillating circuit, constitute the dialing tone circuit by capacitor C 24 with the continuous input that transfers to audio frequency amplification circuit IC6 of the contact J4A of relay J 4; Another part of control circuit is the effect by button in the coding circuit 8, controllable silicon STR1 is triggered, the positive pole of STR1 links to each other by the positive pole of K switch 4 with power supply, ground connection behind the winding of the negative pole series relay J4 of STR1 is finished conversion between audio signal, dialing tone and the busy tone by its contact J4A; Finish conversion between dialing tone and the audio signal by one group of contact of J2A; Also have the effect by the contact J2B of relay J 2 in the control circuit, the moving plate D of J2B links to each other with the positive pole of power supply through diode D12, and the end of the fixed contact C of J2B links to each other with the power end of power amplifier IC9, coding circuit IC7; Another fixed contact E of J2B exports busy-back signal by integrated circuit (IC) 10 power supplies of resistance R 58 in the busy tone phonation circuit by J2A, what link to each other with IC10 is capacitor C 43, C44, C49 and resistance R 51-R56 and R58, D22 is a voltage-stabiliser tube, one end of resistance R 56 links to each other with an end of resistance R 58, the base stage of other end allomeric pipe BG13 links to each other, the base stage of the collector electrode allomeric pipe BG8 of BG13 links to each other, fixed point with K switch 4 behind the winding of the collector electrode series relay J3 of BG8 links to each other, one end of the electric shock of J3 is continuous with the positive pole of electric current by the fixed point of K4, and another contact links to each other with the power supply pin of coding integrated circuit (IC) 7 by diode D11; With the continuous positive pole that also has diode D20 of the contact E of relay J 2, the negative pole of D20 links to each other by the trigger electrode of resistance R 40 with controllable silicon STR1.

The utility model has following advantage compared with the prior art:

1. digital keys dialing is reliable, automatic control one setting-up time of delaying time ring time, and dialing tone, echo, busy(-back) tone (busy tone) are multiple functional, and duplex conversation speech is clear.

2. the utility model also has the function of grouping busy, presses and can realize conference call functions after grouping busy key.

3. owing to this product circuit gain control range wide (can reach 60 decibels), power output is greater than 4W, and speech range can reach 50 to 100 kilometers between the unit, makes it to be fit to program circuit loop resistance variation requirement greatly, inserts existing program circuit and gets final product work.

4. working power can adopt the alternating current-direct current mode of conversion automatically, does not select power supply.

Description of drawings of the present utility model:

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

Fig. 2. the circuit theory diagrams of the coding in the utility model, transmission part and interlock circuit.

Fig. 3. the circuit theory diagrams of the utility model amplification, decoding, control section and interlock circuit.

Embodiment of the present utility model.

Referring to Figure of description 1.Basic principle of the present utility model and structural member are: it comprises that the signal sending circuit and signal receiving circuit and the control circuit etc. that are made of coding circuit, decoding circuit, audio amplifier circuit, power amplification circuit, ringing circuit, busy tone circuit form.In the signal sending circuit part, the output of coding circuit links to each other with the input of power amplification circuit, input with power amplification circuit after voice signal amplifies through pre-amplification circuit links to each other, input with power amplification circuit after voice signal amplifies through pre-amplification circuit links to each other, the output of power amplification circuit links to each other with the input of step-up transformer B1, the output output boost signal of transformer B1.In the signal receiving circuit part, input with decoding circuit after the signal one tunnel that circuit is sent here amplifies through another pre-amplification circuit links to each other, the output of decoding circuit links to each other with the input of decimal system change-over circuit, and an end of change-over circuit links to each other with circuits for triggering and ring back tone circuit with time-delay control through behind locking circuits for triggering and the level shifting circuit; One output of locking circuits for triggering links to each other with the input of control circuit; Another road of the signal that circuit is sent here links to each other with audio frequency reception, amplifying circuit.In the control circuit part, two outputs of control circuit link to each other with busy tone generation circuit with dialing tone generation circuit respectively, and another output of control circuit links to each other with the big circuit of audio interface retractable of signal receiving circuit.

Referring to Figure of description 2, the parts of signal sending circuit of the present utility model are to become decoding circuit by integrated circuit (IC) 7 be attached thereto the button that connects etc. and form, the 7-8 pin of IC7 meets crystal oscillator JX1, and code signal links to each other with the base stage of the transistor BG9 of pre-amplification circuit with resistance W1 by capacitor C 23; Transistor amplifier circuit BG10, the BG9 that front end circuit is amplified by two-stage and be attached thereto the capacitor C 34-C39, the resistance R 42-R47 that connect and form, wherein, BG9 is an emitter output circuit, to reduce the input impedance of power amplifier, the output of Mike MC1 is continuous with the base stage of BG10 through capacitor C 35, the other end ground connection of MC1 (negative pole of power supply); Power amplification circuit is made up of power amplification circuit IC9 and the capacitor C 40-C42 that is attached thereto thereof and resistance R 49 and R52, the signal of BG9 emitter-base bandgap grading output links to each other by the input of capacitor C 39 with IC9, link with the elementary of transformer B1 by capacitor C 42 power output signals, the contact of the elementary other end by K switch 5 through loud speaker Y2 after ground connection, output voltage passes through K switch 1 to line output signal through secondary the boosting of transformer B1 after.

Referring to Figure of description 3, signal receiving circuit in the utility model is to link to each other by the input of capacitor C 6 with the integrated circuit (IC) 1 with strong automatic gain control, also be connected with capacitor C 1-C11 and resistance R 1-R6 on the IC1, resistance R 5, R6 and diode D1, capacitor C 8 constitute automatic gain control circuit, make the output voltage of IC1 keep constant in certain scope, IC1 is by capacitor C 11, C13 and resistance R 8 output voltage signals; Decoder ic IC2 and the resistance R 8-R10 that is attached thereto, crystal oscillator JX1 and capacitor C 15 are formed decoding circuit, signal after decoding circuit is deciphered by the 11-14 pin output of IC2 is also respectively with 10 of decimal system change-over circuit IC3,13,12,11 pin link to each other, the output pin 1-7 of IC3,9,14, gating signal after the 15 output conversions triggers integrated circuit (IC) 4 to locking, 3 pin of IC4 link to each other with 3 pin of IC3,7 of IC4,11,15 pin can link to each other according to the arbitrary output pin of coding needs with IC3, constitute the specific coding of this machine, this machine of gating in this way, IC4 outputs signal to the base stage of the BG1 of level shifting circuit by diode D4, and the collector electrode output triggering signal by BG2 is given input 2 pin of integrated circuit (IC) 5 after BG1 and BG2 amplification, be connected with capacitor C 17-C19 and resistance R 19-R22 on the IC5, time-delay control links to each other with the base stage of triggering signal through resistance R 22 allomeric pipe BG3, on the collector electrode of BG3, be connected with the winding of relay J 1, the other end of J1 winding links to each other the grounded emitter of BG3 with the positive pole of power supply; The end of one group of contact J1B of relay J 1 links to each other with the positive pole of power supply, and the other end links to each other with the collector electrode of the transistor BG4 of the feeder ear of ring back tone integrated circuit (IC) 11 and amplification output circuit, and continuous with an end of button 8 by diode D7, D19; Be connected with the amplifying circuit that ring integrated circuit (IC) 11 and transistor BG4, BG5 constitute on the positive pole of D7, bell signal is exported an end that connects loud speaker through the collector electrode of BG5, and the other end of loud speaker Y3 links to each other with the positive pole of D7; The end of another contact J1A of relay J 1 links to each other with the output of integrated regulator IC12, and the other end links to each other with 6 pin of integrated circuit (IC) 4 by diode D5, also passes through diode D6 on this end with integrated circuit (IC) 3; 5 pin link to each other to form lock-in circuit; The power supply circuits that also connect integrated circuit (IC) 1, IC2, IC3, IC4, IC8 on the output of integrated regulator IC12; Audio amplifier circuit is the audio signal that circuit transmits, by the contact J2A of control circuit, the effect of J4A, to link to each other by the input of capacitor C 31 through the audio signal after resistance R 38, the R39 dividing potential drop with integrated circuit (IC) 6, with IC6 link to each other also have capacitor C 26-C31, C49 and, IC6 gives earphone Y1 by capacitor C 27 output audio signals, and resistance R 37 is short range damping resistances.

Referring to Figure of description 2 and accompanying drawing 3, control circuit of the present utility model is that a NAND gate input of integrated circuit (IC) 8 is continuous with an output 2 pin of integrated circuit (IC) 4, after another group NAND gate circuit of signal process IC8 is anti-phase, base stage through resistance R 28 allomeric pipe BG7 links to each other, and after transistor BG6 amplifies control relay J2, one end of the electromagnetism winding of J2 links to each other the other end ground connection of winding with the collector electrode of BG6; Two groups of NAND gate circuit in addition of IC8 constitute an oscillating circuit, constitute the dialing tone circuit by capacitor C 24 with the continuous input that transfers to audio frequency amplification circuit IC6 of the contact J4A of relay J 4; Another part of control circuit is the effect by button in the coding circuit 8, controllable silicon STR1 is triggered, the positive pole of STR1 links to each other by the positive pole of K switch 4 with power supply, ground connection behind the winding of the negative pole series relay J4 of STR1 is finished conversion between audio signal, dialing tone and the busy tone by its contact J4A; Finish conversion between dialing tone and the audio signal by one group of contact of J2A; Also have the effect by the contact J2B of relay J 2 in the control circuit, the moving plate D of J2B links to each other with the positive pole of power supply through diode D12, and the end of the fixed contact C of J2B links to each other with the power end of power amplifier IC9, coding circuit IC7; Another fixed contact E of J2B exports busy-back signal by integrated circuit (IC) 10 power supplies of resistance R 58 in the busy tone phonation circuit by J2A, what link to each other with IC10 is capacitor C 43, C44, C49 and resistance R 51-R56 and R58, D22 is a voltage-stabiliser tube, one end of resistance R 56 links to each other with an end of resistance R 58, the base stage of other end allomeric pipe BG13 links to each other, the base stage of the collector electrode allomeric pipe BG8 of BG13 links to each other, fixed point with K switch 4 behind the winding of the collector electrode series relay J3 of BG8 links to each other, one end of the electric shock of J3 is continuous with the positive pole of electric current by the fixed point of K4, and another contact links to each other with the power supply pin of coding integrated circuit (IC) 7 by diode D11; With the continuous positive pole that also has diode D20 of the contact E of relay J 2, the negative pole of D20 links to each other by the trigger electrode of resistance R 40 with controllable silicon STR1.

Electronic device in the utility model can be by following selection of parameter:

Resistance R 1-R64 can select the common metal film resistance for use, and capacitor C 1-C50 can select electrochemical capacitor, ceramic disc capacitor, leaded multilayer ceramic capacitor etc. as required for use; In the diode, D1, D2, D5, D8, D9, D11-D14, D16-D19, D29 can select 1N4148 for use, D3 selects 2AP9 for use, D20-D22, D24-D27 select 1N4007 for use, D28, D30 are the light-emitting diodes of different colors, D15, D10 are the voltage-stabiliser tubes of 7.5V, and D6, D23 are the voltage-stabiliser tubes of 6V, and D7 is the voltage-stabiliser tube of 3.5V; In the triode, BG1, BG2, BG4, BG6, BG8, BG9, BG11 are LM9014, and BG3, BG7 are 8050, BG5, BG10 are 9015, and BG12, BG13 are 3AX83, and B1 is a transformer, W is the 100K potentiometer, and JX1, JX2 are the crystal oscillators of 3.579545MHz, and J1-J5 is a relay; STR1 is a common 1-3 peace controllable silicon; Integrated circuit is IC1=uPC1350, IC2=MJ8870, IC3=CD4028, IC4=CD4043, IC5=NE555, IC6=LM386-3; IC7=95087, IC8=CD4011, IC9=TDA2030, IC10=CD4001, IC11=HFC1500, IC12=LM7806; Y1-Y3 is a loud speaker, and MC1 is a microphone.

Using method of the present utility model and basic functional principle are: Fig. 2, shown in Figure 3 be the state of depressing receiver, when other phone is wailed, the signal via line by resistance R 59 capacitor C 6 with amplifying circuit IC1(upc1350) input link to each other, signal passes through IC2(MJ8870 after amplifying) decoding, the output decoded signal is given IC3, and as not being this machine of selective call, 7,11,15 ends of IC4 high level can not occur, 1 pin of IC4 can not be a low level, and following circuit will be kept normality.If the coding of this machine is 234,2,15,1 pin with IC3 when dispatching from the factory links to each other with 7,11,15 pin of IC4 respectively, if calling is plane No. 234, then 7 of IC4,11,15 pin will be high level, the 1 pin output low level of IC4, make not conducting of BG1, the BG2 conducting triggers IC5, make it adhesive by relay J 1, make the positive pole of D5, D6, D7 be in high potential, and make ringing circuit IC11 work, notice is answered the call.Answer the call as nobody, surpass the time of delay that IC circuit 5 is set, as 20 seconds, the output of IC5 was low level, the J1 dead electricity, and circuit returns to normal.Have the people to answer the call between time delay, it will pick up a receiver, and make K switch 1, K4 closure, transtation mission circuit gets, transtation mission circuit work, and press 9 keyboards, make 2 pin of IC4 be locked in high potential, move by J2, control makes busy tone send out the device power supply, as also having called telephone, to represent that this machine works, and pass through IC9(2030) speech is passed speech to the other side by transformer B1.Meanwhile, the other side's voice signal is the same IC6(LM386-3 in contact by J2A, J4A after resistance R 38, R39 dividing potential drop) input link to each other, after IC6 amplifies, hear that from loud speaker Y1 the other side's sound finishes obedient function.

As want a certain phone of dial-up, mention receiver, K4 closure, coding circuit IC7(95087), amplifying circuit (BG9, BG10), IC9(TDA2030) supply lines rood electricity, earlier by 8 keyboards, the J4 adhesive, IC6 connects with circuit, and code signal boosts the back to the circuit transmission, as subscriber engaged by IC9 amplification, transformer B1, to hear the sound of the other side's busy tone generator, the expression subscriber engaged.Nobody meets sb. at the airport as the other side, will not have the possibility of conversation.Answer as the other side, can from Y1, hear the other side's sound, finish dial-up, conversation overall process.

As grouping busy function, arbitrary machine can be considered main frame, and all the other all are extension sets, the J5A moving plate ground connection of extension set, and decoding circuit lost efficacy, and all was in strobe state, is equivalent to a machine multimachine is conversed, and all the other functions are identical with the unit conversation.

Claims

1, a kind of special service telephone set, it comprises that signal sending circuit, signal receiving circuit and the control circuit etc. that are made of coding circuit, decoding circuit, audio amplifier circuit, power amplification circuit, ringing circuit, busy tone circuit form, and it is characterized in that:

A. signal sending circuit is that the output of coding circuit links to each other with the input of power amplification circuit, input with power amplification circuit after voice signal amplifies through pre-amplification circuit links to each other, the output of power amplification circuit links to each other with the input of step-up transformer B1, and the output output boost signal of transformer B1 is to circuit;

B. signal receiving circuit is that the signal one tunnel that circuit is sent here links to each other through the input of another pre-amplification circuit amplification back with decoding circuit, the output of decoding circuit links to each other with the input of decimal system change-over circuit, and an end of change-over circuit links to each other with circuits for triggering and ring back tone circuit with time-delay control through behind locking circuits for triggering and the level shifting circuit; One output of locking circuits for triggering links to each other with the input of control circuit; Another road of the signal that circuit is sent here links to each other with audio frequency reception, amplifying circuit;

C. control circuit is that two outputs of control circuit link to each other with busy tone generation circuit with dialing tone generation circuit respectively, and another output of control circuit links to each other with the big circuit of audio interface retractable of signal receiving circuit.

2, a kind of special service telephone set according to claim 1, the parts that it is characterized in that wherein said signal sending circuit are to become decoding circuit by integrated circuit (IC) 7 be attached thereto the button that connects etc. and form, the 7-8 pin of IC7 meets crystal oscillator JX1, and code signal links to each other with the base stage of the transistor BG9 of pre-amplification circuit with resistance W1 by capacitor C 23; Transistor amplifier circuit BG10, the BG9 that front end circuit is amplified by two-stage and be attached thereto the capacitor C 34-C39, the resistance R 42-R47 that connect and form, wherein, BG9 is an emitter output circuit, to reduce the input impedance of power amplifier, the output of Mike MC1 is continuous with the base stage of BG10 through capacitor C 35, the other end ground connection of MC1 (negative pole of power supply); Power amplification circuit is made up of power amplification circuit IC9 and the capacitor C 40-C42 that is attached thereto thereof and resistance R 49 and R52, the signal of BG9 emitter-base bandgap grading output links to each other by the input of capacitor C 39 with IC9, link with the elementary of transformer B1 by capacitor C 42 power output signals, the contact of the elementary other end by K switch 5 through loud speaker Y2 after ground connection, output voltage passes through K switch 1 to line output signal through secondary the boosting of transformer B1 after.

3, a kind of special service telephone set according to claim 1, it is characterized in that wherein said signal receiving circuit is to link to each other by the input of capacitor C 6 with the integrated circuit (IC) 1 with strong automatic gain control, also be connected with capacitor C 1-C11 and resistance R 1-R6 on the IC1, resistance R 5, R6 and diode D1, capacitor C 8 constitute automatic gain control circuit, make the output voltage of IC1 keep constant in certain scope, IC1 is by capacitor C 11, C13 and resistance R 8 output voltage signals; Decoder ic IC2 and the resistance R 8-R10 that is attached thereto, crystal oscillator JX1 and capacitor C 15 are formed decoding circuit, signal after decoding circuit is deciphered by the 11-14 pin output of IC2 is also respectively with 10 of decimal system change-over circuit IC3,13,12,11 pin link to each other, the output pin 1-7 of IC3,9,14, gating signal after the 15 output conversions triggers integrated circuit (IC) 4 to locking, 3 pin of IC4 link to each other with 3 pin of IC3,7 of IC4,11,15 pin can link to each other according to the arbitrary output pin of coding needs with IC3, constitute the specific coding of this machine, this machine of gating in this way, IC4 outputs signal to the base stage of the BG1 of level shifting circuit by diode D4, and the collector electrode output triggering signal by BG2 is given input 2 pin of integrated circuit (IC) 5 after BG1 and BG2 amplification, be connected with capacitor C 17-C19 and resistance R 19-R22 on the IC5, time-delay control links to each other with the base stage of triggering signal through resistance R 22 allomeric pipe BG3, on the collector electrode of BG3, be connected with the winding of relay J 1, the other end of J1 winding links to each other the grounded emitter of BG3 with the positive pole of power supply; The end of one group of contact J1B of relay J 1 links to each other with the positive pole of power supply, and the other end links to each other with the collector electrode of the transistor BG4 of the feeder ear of ring back tone integrated circuit (IC) 11 and amplification output circuit, and continuous with an end of button 8 by diode D7, D19; Be connected with the amplifying circuit that ring integrated circuit (IC) 11 and transistor BG4, BG5 constitute on the positive pole of D7, bell signal is exported an end that connects loud speaker through the collector electrode of BG5, and the other end of loud speaker Y3 links to each other with the positive pole of D7; The end of another contact J1A of relay J 1 links to each other with the output of integrated regulator IC12, and the other end links to each other with 6 pin of integrated circuit (IC) 4 by diode D5, also passes through diode D6 on this end with integrated circuit (IC) 3; 5 pin link to each other to form lock-in circuit; The power supply circuits that also connect integrated circuit (IC) 1, IC2, IC3, IC4, IC8 on the output of integrated regulator IC12; Audio amplifier circuit is the audio signal that circuit transmits, by the contact J2A of control circuit, the effect of J4A, to link to each other by the input of capacitor C 31 through the audio signal after resistance R 38, the R39 dividing potential drop with integrated circuit (IC) 6, with IC6 link to each other also have capacitor C 26-C31, C49 and, IC6 gives earphone Y1 by capacitor C 27 output audio signals, and resistance R 37 is short range damping resistances.

4, a kind of special service telephone set according to claim 1, it is characterized in that wherein said control circuit is that a NAND gate input of integrated circuit (IC) 8 links to each other with an output 2 pin of integrated circuit (IC) 4, after another group NAND gate circuit of signal process IC8 is anti-phase, base stage through resistance R 28 allomeric pipe BG7 links to each other, and after transistor BG6 amplifies control relay J2, one end of the electromagnetism winding of J2 links to each other the other end ground connection of winding with the collector electrode of BG6; Two groups of NAND gate circuit in addition of IC8 constitute an oscillating circuit, constitute the dialing tone circuit by capacitor C 24 with the continuous input that transfers to audio frequency amplification circuit IC6 of the contact J4A of relay J 4; Another part of control circuit is the effect by button in the coding circuit 8, controllable silicon STR1 is triggered, the positive pole of STR1 links to each other by the positive pole of K switch 4 with power supply, ground connection behind the winding of the negative pole series relay J4 of STR1 is finished conversion between audio signal, dialing tone and the busy tone by its contact J4A; Finish conversion between dialing tone and the audio signal by one group of contact of J2A; Also have the effect by the contact J2B of relay J 2 in the control circuit, the moving plate D of J2B links to each other with the positive pole of power supply through diode D12, and the end of the fixed contact C of J2B links to each other with the power end of power amplifier IC9, coding circuit IC7; Another fixed contact E of J2B exports busy-back signal by integrated circuit (IC) 10 power supplies of resistance R 58 in the busy tone phonation circuit by J2A, what link to each other with IC10 is capacitor C 43, C44, C49 and resistance R 51-R56 and R58, D22 is a voltage-stabiliser tube, one end of resistance R 56 links to each other with an end of resistance R 58, the base stage of other end allomeric pipe BG13 links to each other, the base stage of the collector electrode allomeric pipe BG8 of BG13 links to each other, fixed point with K switch 4 behind the winding of the collector electrode series relay J3 of BG8 links to each other, one end of the electric shock of J3 is continuous with the positive pole of electric current by the fixed point of K4, and another contact links to each other with the power supply pin of coding integrated circuit (IC) 7 by diode D11; With the continuous positive pole that also has diode D20 of the contact E of relay J 2, the negative pole of D20 links to each other by the trigger electrode of resistance R 40 with controllable silicon STR1.