CN2267585Y - Double sound and multi-frequency dialing type telephone for preventing fraudulent use - Google Patents

Abstract

The utility model relates to an embezzlement preventing device for a telephone, connected in series between a telephone line and a subscriber telephone, and comprising an identifying control circuit for telephone embezzlement, a control circuit for telephone embezzlement, a power circuit, an acoustic-optic alarm circuit and a monitoring amplifying circuit. The control circuit for telephone embezzlement is composed of a DTMF dialing tone generating circuit connected with a DTMF output circuit. Line voltage is lowered when the telephone line is embezzled, and then the identifying control circuit for telephone embezzlement triggers the DTMF dialing tone generating circuit to work and output a group of preset and actually not existing numbers which are preemptively conveyed to the telephone line through the DTMF output circuit, so that an exchanger can not be connected, to reach the goal of preventing embezzlement. The utility model has neither interference nor range constraint.

Description

Dual-tone multifrequency dialing type Device for anti-fraudulent use telephone line

The utility model relates to a kind of telephone subscriber's device, relates to a kind of device that prevents to usurp phone or rather.

At present, in numerous Device for anti-fraudulent use telephone line, generally adopt below three class anti-theft techniques:

1) perturbation technique, the dispensing interference signal influences robber's machine conversation and dialing, makes the phone cisco unity malfunction of illegal parallel operation, but will lose interference effect during away from the alarm certain distance when the free call on sb. else's expense through illegal means phone, thereby anti-theft capability is limited;

2) to dam be dividing technology to low-resistance, promptly sets up shunt circuit in alarm, detects line voltage distribution and reduce behind the machine of robber off-hook, and then the control circuit conducting makes on the circuit and connects low value resistance resistance, causes stealing the machine operating current and reduces and cisco unity malfunction.But increase along with the circuit distance, the control ability of stealing machine is weakened gradually, the loop that low resistance circuit in this explanation alarm forms circuit, can only destroy the robber's machine that uses the pulse mode dialing, because little, thereby can not control the robber's machine that uses double-tone frequency mode to dial fully to the effect that the dual-tone dialing mode is produced;

3) disturb the complex art that combines with shunting.

Most of telephone loops are that diameter is the copper cabling of 0.5mm or 0.4mm, and every kilometer loop resitance is respectively 188,300 ohm, and the user is more than 2 kilometers on the subscriber's line and apart when robber's machine is connected on, and robber's machine just can normally use unaffected.The effect of above-mentioned three kinds of anti-theft techniques all is subjected to the influence of distance between robber's machine and subscriber computer, distance increases deleterious, no matter and the speech quality that the alarm that adopts which kind of technology all can only influence robber's machine can not effectively stop the dialing of robber's machine, the still available double-tone of appropriator frequently mode dial arbitrarily as 160,168, the telephone number of high cost such as long-distance, the user is sustained a loss.

In addition, discharge strong jamming on the line and realize that antitheft meeting causes cross-talk, forms and disturb to the All other routes in the telecommunication cable, is unfavorable for communication quality.And the alarm of employing dividing technology, owing to make the line current shunting, cause line voltage distribution further to descend, make anti-theft circuit enter self-locking state, circuit can not restore after the on-hook of robber's machine, and phone can't be squeezed into, and will influence user's normal use, therefore have to emphasize in some alarm operation instructions: when the machine of robber indicator light is lighted the user should pluck, on-hook once, remove the self-locking state of alarm with this.

Except that above-mentioned three class anti-theft techniques, " dialing restriction " function that also can utilize Local Exchange to provide is carried out effectively antitheft, and the user dials after importing password unlocking, locks behind end of conversation.Owing to need the telephone office business hall to apply for opening an account and paying expense, still have the problem that causes economic loss in case carelessness is forgotten to lock.

The purpose of this utility model is a kind of dual-tone multifrequency dialing type Device for anti-fraudulent use telephone line of design, can thoroughly solve all deficiencies of alarm in the aforementioned analysis, guarantees that fundamentally subscriber's line is not illegally usurped.

The anti-theft technique that the utility model utilization controller combines with switch, promptly actual and non-existent telephone number sends with the Dual Tone Multifrequency mode controller with one group when detecting subscribers feeder the free call on sb. else's expense through illegal means of robber's machine is arranged, make switch can't realize continuing, and no longer accept any dialing and instruct, reach the real anti-purpose of usurping, though its process is identical with proper communication, because switch do not finish this and continue, so accounting fee can not have any impact to communication network yet.

The utility model dual-tone multifrequency dialing type Device for anti-fraudulent use telephone line is serially connected with between telephone loop and subsets, comprises power circuit, and free call on somebody else's expense through illegal means recognition control circuit and anti-free call on somebody else's expense through illegal means control circuit is characterized in that:

Described anti-free call on somebody else's expense through illegal means control circuit produces circuit connection dual-tone multifrequency output circuit by the DTMF pulsing sound and constitutes; The DTMF pulsing sound produces the described free call on somebody else's expense through illegal means recognition control circuit of circuit control termination output, and the dual-tone multifrequency output circuit connects telephone loop.

Described anti-free call on somebody else's expense through illegal means control circuit also comprises an acoustic alarm that is connected with subscribers feeder and a monitoring amplifier circuit and an optical alarm circuit that is connected with power circuit.

Described free call on somebody else's expense through illegal means recognition control circuit is by voltage-stabiliser tube D1, transistor BG1, BG2, resistance R 1, R2, R3, R4 connect and compose, the negative rapids of D1 is connected outside line anode and subscriber phone one end with R4 one end, the D1 anode connects R2 one end, the R2 other end also connects R1 one end and BG1 base stage, the R4 other end also connects the BG1 collector electrode and the BG2 base stage, another termination subscriber phone other end of R1 and R3 one end, BG1 emitter, BG2 emitter and R3 other end extension telephone outside line negative terminal, BG2 collector electrode connect the DTMF pulsing sound and produce the circuit control end.

It is the dialing integrated circuit that has in the direct dialing memory function telephone set that described DTMF pulsing sound produces circuit, the power end of dialing integrated circuit is connected with described power circuit, dialing integrated circuit control end is connected with described free call on somebody else's expense through illegal means recognition control circuit output, the dialing ic output is connected with described dual-tone multifrequency output circuit, and dialing integrated circuit emergency telephone number memory control end is connected with described free call on somebody else's expense through illegal means recognition control circuit.

It is to be manufactured with the double-tone speech IC of number frequently that described DTMF pulsing sound produces circuit.

The free call on sb. else's expense through illegal means machine is as calling subscriber's off-hook the time, anti-free call on somebody else's expense through illegal means control circuit promptly begins to send out number, because what dial-out was gone is a non-existent at all number, switch can't complete connection, voice warning circuit sends " letting, do not have this telephone number down ... " in the meeting demand working, switch is no longer accepted the number of any input when doing voice suggestion, efficiently solves the stolen problem of subscriber's line.

Further specify technology of the present utility model below in conjunction with the embodiment accompanying drawing.

Fig. 1, dual-tone multifrequency dialing type Device for anti-fraudulent use telephone line theory diagram;

Fig. 2, press first kind that Fig. 1 principle realizes and implement circuit diagram;

Fig. 3, press second kind that Fig. 1 principle realizes and implement circuit diagram;

The third enforcement circuit diagram that Fig. 4, map interlinking 1 principle realize;

Referring to Fig. 1, dual-tone multifrequency dialing type Device for anti-fraudulent use telephone line mainly comprises power circuit 10, free call on somebody else's expense through illegal means recognition control circuit 11, produces the anti-free call on somebody else's expense through illegal means control circuit that circuit 12 and dual-tone multifrequency output circuit 13 are formed by the DTMF pulsing sound.Anti-free call on somebody else's expense through illegal means control circuit also can be provided with sound, light indication and monitoring amplifier 14, and dual-tone multifrequency dialing type Device for anti-fraudulent use telephone line is serially connected with between substation 20 and the subscribers feeder 30.

What squeeze in advance in the DTMF pulsing sound produces circuit 12 is a string (5 to 6) non-existent at all telephone number, as continuous 1,3,5 etc.In addition, because different switches there are differences the reaction time of caller off-hook, therefore in order to adapt to all switches, make antitheft control section can shift to an earlier date reaction time in switch, should before the number of sending out of robber's machine, try to be the first and send default 5-6 item sign indicating number, be that handset stealer's anti-theft controller in off-hook has begun to send out number, the number length that is sent is far more than the switch figure place that number can discern of playing a game, can receive 3-4 item sign indicating number to the slower switch of reaction, after receiving discrimination bit, also can receive the invalid dialling of 1-2 position reacting faster switch.

Referring to Fig. 2, A+, the B-outside line of answering the call, C, D connect substation.Form the free call on somebody else's expense through illegal means recognition control circuit by BG1, BG2, R1-R4, D1, D2, can discern and distinguish user's off-hook and circuit is usurped state.IC1 (UM91210) is the special-purpose DTMF signaling circuit of communication, and inside stores particular number in advance.BG4, D3, R7, R8 etc. form the DTMF output circuit, and R9, D4 (redness) form the luminous indicating circuit of usurping, and audio frequency power amplifier integrated circuit (IC) 2 (LM386) is formed monitoring and alarm sound amplifier with C4, R10, W, C6, Y, R11, C5 etc.E and power supply switch tube BG3 constitute power circuit, and for IC1, IC2 provide working power, D2 (green) is used to indicate user job.

Its voltage is the feed voltage (48v) of telephone office when circuit is unloaded, and this moment, voltage-stabiliser tube D1 puncture conducting formed pressure drop on R1, and BG1 conducting BG2 ends, and the control end HK of IC1 is a high level, and IC1 does not work.During user's off-hook, flow through line current on the R3 and to form a constant pressure drop D2 luminous, the indication validated user is using phone, though line voltage distribution decline this moment D1 ends, the pressure drop on the R3 still can make BG1 conducting BG2 still not work by IC1.

When the people usurps circuit, line voltage distribution descends, and BG1 is by, BG2 conducting when being lower than the D1 puncture voltage, and the HK that makes IC1 is an electronegative potential, IC1 enters the starting of oscillation of operating state internal oscillator, and the particular number that deposits in is in advance delivered on the telephone line by BG4 fast in the repeating transmission mode.Along with the also conducting of conducting BG3 of BG2, power supply send D4, IC2 etc. through BG3, and D4 sends ruddiness, and the double-audio signal that audio frequency amplifier will be delivered to the particular number of circuit amplifies as alarm sound.

K is a sense switch among the figure, and closure during operate as normal is opened user after the K switch and can be utilized the anti-effect of usurping of phone inspection of oneself.Alarm utilizes telephone line power supply and battery E work, and the number that can store in the long preservation IC1 chip before product is formally enabled because C2 is arranged, can not make contents lost among the IC1 simultaneously when changing battery.The employing powered battery also can reduce the requirement to the withstand voltage parameter of components and parts.

Referring to Fig. 3, implement circuit and utilized that existing dialing integrated circuit (as UM91265) produces circuit as alarm DTMF pulsing sound in the dual tone phone machine for second kind shown in Figure 3.BG1, BG2, BG4, BG5 and peripheral related elements R1～R5, voltage-stabiliser tube D1, D2 and C1, C2, D3 etc. form the free call on somebody else's expense through illegal means recognition control circuit, identification circuit change in voltage and user's off hook state, and the DTMF pulsing sound is produced circuit control.There is being BG2 when usurping also to have effect concurrently into the dial-up circuit power supply.BG3 and peripheral cell R6, R7 form the dual-tone multifrequency output circuit, to telephone line output dtmf signal.

Fig. 3 circuit production then becomes the telephone set with theftproof performance in telephone set, can utilize the direct dialing memory function that generally possesses in the commercially available telephone set to finish.The circuit that increases during user's off-hook is not worked, circuit has the circuit part that increases when usurping just to work, but because the phone switch hook is in off-state, therefore phone except that dial-up circuit, give, PAC circuit all do not work, after number sends automatically and finishes, because increasing that the electric current of partial circuit is very little can locked circuit, steal circuit restoration after the machine on-hook.

Among Fig. 3, BG5 is for sending out number switching tube, and its drain electrode links to each other with emergency telephone number memory control end R4, the C4 of dialing IC respectively with source electrode.Tandem working when BG3 and BG4 are connected in series in and send out number, the operate as normal that can not influence phone does not promptly produce shunting to the double-audio signal of dialing IC output, line voltage distribution reduces when circuit has the people to usurp, the operating voltage of BG2 conducting output dialing integrated circuit, BG4, BG5 conducting, dialing IC work is delivered to telephone line by BG3 in double-tone frequency mode with the particular number that originally was stored in the sheet, finishes antitheft process.

Antitheft number can be by the storage means input according to number of phone button.

Referring to Fig. 4, the third shown in the diagram implemented circuit and utilized integrated speech IC sheet to produce circuit as the DTMF pulsing sound.BG1, BG2, R1-R4 and peripheral related elements D1-D3, C1, C2 form the free call on somebody else's expense through illegal means recognition control circuit, and wherein BG2 also holds concurrently and is integrated speech IC circuit 3 (SR88A is serial or other are serial) power supply.Integrated speech sheet IC3 has one group of DTMF number of making in advance for the DTMF pulsing sound produces circuit, and R5, C3 are the Resistor-Capacitor Units of voice sheet oscillator section.BG3, R6, R7 form the dual-tone multifrequency output circuit, are responsible for sending dtmf signal to telephone line.

When telephone line had free call on sb. else's expense through illegal means, line voltage distribution descended, BG1 ends, the BG2 conducting, and the HK end of IC3 is high level, triggers IC3 work.

The course of work of the utility model Device for anti-fraudulent use telephone line is identical with a communication process, but switch do not continue, and can thoroughly solve subscriber phone by the problem of free call on sb. else's expense through illegal means, and subscriber's line is not produced interference, is not subjected to the restriction of circuit distance.Adopt the double-tone mode number of sending out frequently, no matter the sign indicating number position how long, and it is certain to send out the used time of number, helps the number of robbing fast.

Claims (5)

1, a kind of dual-tone multifrequency dialing type Device for anti-fraudulent use telephone line is serially connected with between telephone loop and subsets, comprises power circuit, and free call on somebody else's expense through illegal means recognition control circuit and anti-free call on somebody else's expense through illegal means control circuit is characterized in that:

Described anti-free call on somebody else's expense through illegal means control circuit produces circuit connection dual-tone multifrequency output circuit by the DTMF pulsing sound and constitutes; The DTMF pulsing sound produces the described free call on somebody else's expense through illegal means recognition control circuit of circuit control termination output, and the dual-tone multifrequency output circuit connects telephone loop.

2, dual-tone multifrequency dialing type Device for anti-fraudulent use telephone line according to claim 1 is characterized in that: described anti-free call on somebody else's expense through illegal means control circuit also comprises an acoustic alarm that is connected with subscribers feeder and a monitoring amplifier circuit and an optical alarm circuit that is connected with power circuit.

3, dual-tone multifrequency dialing type Device for anti-fraudulent use telephone line according to claim 1, it is characterized in that: described free call on somebody else's expense through illegal means recognition control circuit is by voltage-stabiliser tube D1, transistor BG1, BG2, resistance R 1, R2, R3, R4 connects and composes, the negative rapids of D1 is connected outside line anode and subscriber phone one end with R4 one end, the D1 anode connects R2 one end, the R2 other end also connects R1 one end and BG1 base stage, the R4 other end also connects the BG1 collector electrode and the BG2 base stage, another termination subscriber phone other end of R1 and R3 one end, the BG1 emitter, BG2 emitter and R3 other end extension telephone outside line negative terminal, BG2 collector electrode connect the DTMF pulsing sound and produce the circuit control end.

4, dual-tone multifrequency dialing type Device for anti-fraudulent use telephone line according to claim 1, it is characterized in that: it is the dialing integrated circuit that has in the direct dialing memory function telephone set that described DTMF pulsing sound produces circuit, the power end of dialing integrated circuit is connected with described power circuit, dialing integrated circuit control end is connected with described free call on somebody else's expense through illegal means recognition control circuit output, the dialing ic output is connected with described dual-tone multifrequency output circuit, and dialing integrated circuit emergency telephone number memory control end is connected with described free call on somebody else's expense through illegal means recognition control circuit.

5, dual-tone multifrequency dialing type Device for anti-fraudulent use telephone line according to claim 1 is characterized in that: it is to be manufactured with the double-tone speech IC of number frequently that described DTMF pulsing sound produces circuit.

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