CN2227892Y - Automatic anwsering function expander for modem - Google Patents

Abstract

The utility model relates to a function expander for modems in computer communication. After receiving signals, a ring current conversion control circuit 1 controls a relay 1J to switch on the working power supply of a modem. After output signals from the output ends of an RI and a CD pass through a level changing circuit 4 and a monostable delay circuit 5, a counter 6 is controlled to output signals to trigger a speech chip and a sound enlarging circuit 7 to distinguish a conversation state from a communication state. After receiving and conversion, the modem controls a delay switch circuit 2 to output signals to control the relay 1J in the ring current conversion control circuit to switch off the power of the modem. The utility model has simple structure and perfects the functions of the modem.

Description

Modulator-demodulator automatic answer function expander

The utility model relates to a kind of modulator-demodulator automatic answer function expander that is used for compunication.

Universal day by day along with computer and program controlled telephone, computer utilizes public telephone network to carry out remote data communication more and more widely, is the indispensable equipment that carries out this communication with modulator-demodulator.At present, when being the modulator-demodulator MOdem automatic-answering back device of representative with U.S. smartmodem, MOdem in running order both having wasted energy has constantly also shortened the useful life of MOdem, have again, if when having the people to call, concerning we, MOdem off-hook ring is no longer loud; To the other side say put through phone after, one comes sound also not have.Rather inconvenience when making its automaticdata communication situation that is used for industrial control system.

The modulator-demodulator automatic answer function expander that the purpose of this utility model is to provide a kind of power supply of energy auto switching modulator-demodulator and people's response process is called out in ring when the conversation task.

The utility model is finished with following mode: modulator-demodulator automatic answer function expander is by the photoelectrical coupler CD that is connected on the telephone wire ₁Output meets switch triode BG ₃Base stage, at switch triode BG ₃Emitter serial connection relay 1J constitute ringing-current conversion control circuit 1; Delay switch circuit 2 is by photoelectrical coupler CD ₂Normal opened contact 1J through relay 1J _1-2The line of answering the call, photoelectrical coupler CD ₂Output series resistor R ₄And capacitor C ₂Form timing circuit, in capacitor C ₂The normally closed contact 1J of electrical equipment 1J is also succeeded in two ends _1-1, from capacitor C ₂Last dividing potential drop output is through unijunction transistor BG ₁Meet switch triode BG ₂Base stage, switch triode BG ₂Collector electrode meet switch triode BG in the ringing-current conversion and control control circuit 1 ₃Base stage; Between modulator-demodulator Modem circuit 3 and power supply, be connected in series the normal opened contact 1J of relay 1J _3-2The RI end output of modulatedemodulate device Modem circuit 3 triggers single stabilization delay circuit [5] time-delay through level-conversion circuit 4 and outputs signal to counter 6, the CD end output of modulator-demodulator Modem circuit 3 inputs to the clear terminal of counter 6 behind level-conversion circuit 4, at the output termination speech chip and the loudspeaker circuit 7 of counter 6.Level-conversion circuit 4 is to be made of integrated circuit MC1489, and single stabilization delay circuit 5 is to be made of monostable trigger integrated circuit 74LS123 and outer meeting resistance and electric capacity, and counter 6 is to be made of integrated circuit 74LS93.

The utility model is that modulator-demodulator automatic answer function expander is to be applied to not enough development of Industry Control automaticdata communication at the modulator-demodulator product that is representative with U.S. HAYES.It can be implemented in the power supply of opening modulator-demodulator MOdem when calling out automatically, behind communication or end of conversation, close the MOdem power supply automatically, thereby energy savings and maintenance of equipment update cost greatly, in addition when MOdem automatic-answering back device is session services, realize that this power ringing calls out people's response process and give the other side with waiting signal, thereby truly make a phone possess the conversation and the multiplexing function of communicating by letter.The utility model expander is simple in structure, reliable operation, and cost is low, is a kind of comparatively ideal MOdem additional function expander.

Fig. 1 is the utility model circuit block diagram.

Fig. 2 is this practical circuit schematic diagram.

Below in conjunction with accompanying drawing this practicality is done an explanation:

As shown in Figure 1, the utility model is by ringing-current conversion control circuit 1, delay switch circuit 2, and modulator-demodulator Modem circuit 3, level-conversion circuit 4, single stabilization delay circuit 5, counter 6, speech chip and loud speaker 7 are formed.As shown in Figure 2, ringing-current conversion control circuit 1 is by being connected to telephone wire L ₁And L ₂On diode D ₆, D ₁And capacitor C ₅With photoelectrical coupler CD ₁Output meets switch triode BG ₃Base stage, relay 1J serial connection switch triode BG ₃Emitter, the normal opened contact 1J of relay 1J _2-2Be attempted by photoelectrical coupler CD ₁Output on.Delay switch circuit 2 is by photoelectrical coupler CD ₂Output series resistor R ₄And capacitor C ₂Form timing circuit, in capacitor C ₂Go up and succeed the normally closed contact 1J of electrical equipment 1J _1-1, from capacitor C ₂Last dividing potential drop output order junction transistors BG ₁Grid, unijunction transistor BG ₁Drain electrode output is through diode D ₅Meet switch triode BG ₂Base stage, switch triode BG ₂Grounded emitter, its collector electrode is through voltage-stabiliser tube D ₂Meet triode BG ₃Base stage.Be connected in series relay 1J between modulator-demodulator Modem circuit 3 and the power supply ₁Normal opened contact 1J _3-23 outputs of modulator-demodulator Modem circuit connect level-conversion circuit 4, level-conversion circuit 4 is to be made of integrated circuit MC1489, export single stabilization delay circuit 5 to from the output of level-conversion circuit 4, single stabilization delay circuit 5 is to be made of monostable integrated circuit 74LS123 and outer meeting resistance electric capacity, another output of level-conversion circuit 4 inputs to the clear terminal CLK of counter 6 through diode, single stabilization delay circuit 5 is behind its A end incoming level signal lag, export the input of counter 6 to from its D end, counter 6 is to adopt 74LS93, from the D of counter 6 ₀End exports speech chip to and promotes loud speaker 7 work.

The operation principle of the utility model circuit is:

As shown in Figure 2, when ring, telephone wire L ₁And L ₂There is the ringing-current voltage signal about 90 volts at two ends, and this signal inputs to ringing-current conversion control circuit 1, and ringing-current is through diode D ₆And capacitor C ₅Make photoelectrical coupler CD ₁Lumination of light emitting diode, CD ₁Interior photosensitive tube internal resistance diminishes and conducting rapidly, thereby makes triode BG ₃Conducting is serially connected in triode BG ₃Relay 1J energising adhesive on the emitter, its normal opened contact 1J _2-2Closure, short circuit CD ₁Output, and realize self-sustaining, even also triode BG ₃Protect special conducting state, simultaneously the normal opened contact 1J of relay J _3-2Also closed simultaneously, and the power supply of connection modulator-demodulator MOdem makes it in running order, the normally closed contact 1J of relay 1J _1-1Open normal opened contact 1J _1-2Closed, on-delay switching circuit 2, after the 3 energized work of modulator-demodulator MOdem circuit, the beginning automatic off-hook is replied, its RI end output low level becomes high level through level-conversion circuit 4 (MC1489) level conversion, trigger single stabilization delay circuit 5, single stabilization delay circuit 5 is by monostable trigger 74LS123 and outer meeting resistance, electric capacity constitutes, the delay adjustments time of this single stabilization delay circuit 5 can be set at about 6 seconds, input from single stabilization delay circuit 5 output high level to counter 6 (74LS93), the CD end of MOdem circuit 3 outputs signal to level-conversion circuit 4 (MC1489) and carries out level conversion after diode inputs to the clear terminal of counter 6 (74LS93), if in the setting-up time of single stabilization delay circuit 5, the CD end output low level of MOdem, after level shifting circuit 4 converts high level to, counter 6 is carried out zero clearing, then counter 6 outputs are low level, and do not trigger speech chip and speaker circuit 7, just not sending ring calls out people's back-signalling, then expression MOdem this moment is in the data communication state, and when in the setting-up time of single stabilization delay circuit 5, convert low level at the CD of MOdem end output high level to through level conversion level 4, this moment, the CD output end signal was invalid to counter 6, then counter 6 output high level triggering speech chips and speaker circuit 7 send ringing signal, are expressed as the session services shape this moment.Behind the MOdem automatic off-hook, at telephone wire L ₁And L ₂Both end voltage is lower than below 10 volts, at this moment photoelectrical coupler CD ₂Can not conducting work, delay switch circuit 2 is not worked yet.When the MOdem received communication finish or the on-hook of conversing after, at L ₁And L ₂There are about 60 volts of direct voltages at two ends, at this moment, and photoelectrical coupler CD ₂Conducting, and this moment triode BG ₃Be self-sustaining in conducting state, relay 1J adhesive, its normally closed contact 1J _1-1Open, power supply is through resistance R ₄To capacitor C ₂Charging is delayed time, and works as capacitor C ₂Last voltage rises to unijunction transistor BG gradually ₁Peak point voltage the time, BG ₁Conducting, thus make switch triode BG ₂Conducting, BG ₂Collector electrode through voltage-stabiliser tube D ₂Meet the triode BG in the ringing-current change-over circuit 1 ₃Base stage, make BG ₃Base potential descend, its collector current reduces, and makes relay 1J discharge its normal opened contact 1J _3-2Open, thus the power supply of disconnection MOdem, and the normally closed contact 1J of relay 1J _1-1Return closure, make capacitor C ₂Discharge performs down the preparation of task.

Claims (2)

1. a modulator-demodulator automatic answer function expander is characterized in that by the photoelectrical coupler CD that is connected on the telephone wire ₁Output meets switch triode BG ₃Base stage, at switch triode BG ₃Emitter serial connection relay 1J constitute ringing-current conversion control circuit [1]; Delay switch circuit [2] is by photoelectrical coupler CD ₂Normal opened contact 1J through relay 1J _1-2The line of answering the call, photoelectrical coupler CD ₂Output series resistor R ₄And capacitor C ₂Form timing circuit, in capacitor C ₂The normally closed contact 1J of electrical equipment 1J is also succeeded in two ends _1-1, from capacitor C ₂Last dividing potential drop output is through unijunction transistor BG ₁Meet switch triode BG ₂Base stage, switch triode BG ₂Collector electrode meet switch triode BG in the ringing-current conversion control circuit [1] ₃Base stage; Between modulator-demodulator Modem circuit [3] and power supply, be connected in series the normal opened contact 1J of relay 1J _3-2The RI end output of modulatedemodulate device Modem circuit [3] triggers single stabilization delay circuit [5] time-delay through level-conversion circuit [4] and outputs signal to counter [6], the CD end output of modulator-demodulator Modem circuit [3] inputs to the clear terminal of counter [6] behind level-conversion circuit [4], at the output termination speech chip and the loudspeaker circuit [7] of counter [6].

2. according to the described function expander of claim 1, it is characterized in that level-conversion circuit [4] is to be made of integrated circuit MC1489, single stabilization delay circuit [5] is to be made of monostable trigger integrated circuit 74LS123 and outer meeting resistance and electric capacity, and counter [6] is to be made of integrated circuit 74LS93.