CN2185963Y

CN2185963Y - Theft-proof alarm for telephone line

Info

Publication number: CN2185963Y
Application number: CN 93248000
Authority: CN
Inventors: 倪晓文
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-12-15
Filing date: 1993-12-15
Publication date: 1994-12-21
Anticipated expiration: 2003-12-15

Abstract

The utility model relates to a theft-proof alarm for a telephone line used for the subscriber line of a wired automatic telephone and the junction line of a PBX subscriber exchange to prevent the householder telephone line being illegally stolen. The theft-proof alarm for a telephone line is composed of a telephone line interface circuit, a time delay circuit, a blocking charge and discharge circuit, and an alarm circuit. The theft-proof alarm for a telephone line has the advantages of reasonable and simple design, low cost and high reliability. The theft-proof alarm for a telephone line not only can be singly used but also can be arranged in a telephone set.

Description

Theft-proof alarm for telephone line

The utility model relates to a kind of telephone line burglar alarm.Specifically be exactly that the user connects this alarm in the telephone set of oneself or on the telephone wire, just can prevent that any other people this trackage of illegal steal from conversing, and have alarm apparatus.

Raising along with living standards of the people, the development of telecommunications, phone has become requisite means of communication in people's daily life, the work, but, on telephone line, there is others' circuit of people's trespassory taking to use phone often, user's telephone charges is increased, cause the contradiction of user and postal and telecommunication entities, though advanced programme-controlled exchange machine equipment has electronic cipher call blocking function, also easily phone or the broken sign indicating number of multifrequency decoding/pulse decoding are arranged by some band dialing Presentation Functions.

There is the people on the thief-proof problem of telephone line, to do research at present, but because of its complex structure, and easily cause stored-program control exchange work abnormal running after the user installation, can not be incorporated into the power networks.

The purpose of this utility model be to provide a kind of simplicity of design, rationally, cost is low, and do not influence stored-program control exchange work after the user installation, and has the telephone line burglar alarm of warning device.

The utility model is achieved like this: it comprises telephone interface circuit, delay circuit, every straight charge-discharge circuit, sound light alarming circuit.Wherein, telephone interface circuit connects a resistance R 1 by telephone wire a, diode D1, and integrated electro coupler IC1, triode BG1, resistance R 2, and diode D1 connects toggle switch K composition; Delay circuit connects resistance R 4 respectively by ic chip 2, capacitor C 1, C2, and relay J is formed, and 2 pin of ic chip 2 are connected in the emitter of triode BG1; Every straight charge-discharge circuit, by telephone wire a connection-resistance R 3, capacitor C 3, relay J 1-2 toggle switch K also is connected to telephone wire b; Report to the police electricity by road speech music sheet IC3, light-emitting diode D3, loud speaker SP, relay J 1-3 constitute.

Come the utility model done below in conjunction with embodiment and accompanying drawing and describe in further detail:

Accompanying drawing 1 is the utility model circuit structure diagram.

With reference to accompanying drawing: the utility model is by telephone interface circuit, delay circuit, form every straight charge-discharge circuit, warning circuit.Wherein telephone interface circuit connects resistance R 1 by telephone wire a; diode D1, integrated electro coupler 1C1(T1L113), resistance R 2; triode BG1; and diode connects toggle switch K and forms, and R1 is a current-limiting resistance, guarantees T1L113 D2 conducting when on-hook; and D2 ends when carrying machine; diode D1 plays the polarity protection effect, in case a, b line connect instead, D2 is breakdown.K switch is used for making when the user dials alarm to break away from telephone wire and the energy normal dialing.It when on-hook ground vapour, one 48V direct voltage is arranged on the b line, D2 forward conduction, excitation T1L113 output conducting at this moment, this moment, the emitter A point of triode BG1 was a high potential, connect 2 pin of ic chip 2 by the A point, so that start the work of delay circuit control relay when carrying machine.Delay circuit is by ic chip 2(model 555) 7.8 pin 5.6 pin that connect resistance R 4, IC2 respectively connect capacitor C 1, C2 respectively, 3 pin of IC2 connect, relay J, 2 pin of IC2 link to each other with the A point, ic chip 2 forms a monostable trigger-action circuit, R4, C2 parameter set point value are to guarantee relay effective pickup time.Connect resistance R 3 every straight charging circuit by telephone wire a, capacitor C 3, the J1-2 contact of relay is formed, and T1L113 ends when non-owner user carries machine, and the high potential of A point current potential during by on-hook becomes electronegative potential.The relay J adhesive, J1-2, the adhesive simultaneously of J1-3 contact, J1-2 adhesive capacitor C 3 is by resistance R 3 chargings, the dialing tone that this moment, stored-program control exchange was sent here constitutes virtual short through charging circuit, non-owner carries the machine, and the person can't hear normal dialing tone, can't dial, and promptly is attempting having dialled telephone number also can be consumed by capacitor C 3.When he again during on-hook, capacitor C 3 in time discharge by resistance R 3, the voltage on a, the b line is got back to again when having discharged-48V simultaneously, promptly is that he is permanent, at this moment overtime, exchange opportunity is sent howler tone.The adhesive of J1-3 makes the work of speech music sheet, sends chimes of doom, notifies owner, the people is arranged at this telephone line of steal, and alarm circuit is by the J1-3 of relay, contact loud speaker SP, and speech music sheet IC3, light-emitting diode D3 forms.

The theft-proof alarm for telephone line of the utility model design is mainly used on the junction line of automatic wire telephone subscribers feeder and PBX user's switched line machine, prevent that illegal steal householder phone is with weighing, and connect party-line, has simplicity of design, reasonable, the warning function that also has at ordinary times broken string, swinging cross, thief-proof line makes the householder in time find fault and in time declaring so that the circuit on-call maintenance to postal and telecommunication entities. This design has following characteristics:

1, this designing institute adopts Control of Voltage principle, has avoided the passivity of the tone control that switch sends, and it is reliable to be swift in motion.

2, this design all is suitable for audio frequency/Pulse Electric phone.

3, the delay release tech has been adopted in this design, has avoided the alarm descendant for discharging and to the false fault that switch causes, switch system normally being moved.

4, this designing institute has used the speech music warning circuit, and can produce acousto-optic newspaper device.

5, this design can be used separately as product, can be installed in telephone set inside simultaneously again.

Claims

1, a kind of telephone line burglar alarm, it comprises telephone interface circuit, delay circuit, every straight charge-discharge circuit, sound light alarming circuit constitutes, and it is characterized in that:

A, telephone interface circuit: connect resistance R 1, two utmost point villous themeda D1 by telephone wire a, integrated electro coupler 1C1, three utmost point villous themeda BG1, resistance R 2, and two utmost point villous themeda D1 connect toggle switch K composition;

B, delay circuit: by 7,8 pin edge joint resistance R 4 of ic chip 2,5,6 pin of IC2 are edge joint capacitor C 1, C2 respectively, and 3 pin of IC2 connect relay J and constitute, and 2 pin of ic chip 2 are connected in the emitter e of three utmost point villous themeda BG1;

C, every straight charge-discharge circuit, connect capacitor C 3 by telephone wire a by resistance R 3, relay node J1-2, and connect toggle switch K and be connected to telephone wire b;

The d sound light alarming circuit: by power supply, speech music sheet IC3, light-emitting diode D3, loud speaker SP, the node J1-3 of relay J constitutes.

2, telephone line burglar alarm as claimed in claim 1 is characterized in that being connected with the 6-9V power supply at 4,8 pin of ic chip 2 and the collector electrode of triode BG1.