CN2833618Y

CN2833618Y - Anti-theft fault alarm for telephone line

Info

Publication number: CN2833618Y
Application number: CN 200520087160
Authority: CN
Inventors: 陈传励; 江宝松
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-09-13
Filing date: 2005-09-13
Publication date: 2006-11-01
Anticipated expiration: 2015-09-13

Abstract

The utility model relates to an anti-theft fault alarm for telephone lines, which comprises a voltage detecting circuit, a sounding circuit and a relay. The anti-theft fault alarm is characterized in that the input terminal of the voltage detecting circuit is connected with the input terminal of the user telephone line which is input by local telephone network; the output terminal of the voltage detecting circuit is connected with the sounding circuit. After any line of the input terminal of telephone line in local telephone network is connected with a relay control coil in series, the line of the input terminal of telephone line in the local telephone network is connected with one end of the user telephone again; the other line is connected with the other end of the user telephone directly. The normal opening contact of the relay is connected with the output terminal of the voltage detecting circuit; the movable contact of the relay is connected with the ground of the circuit. Thus the anti-theft fault alarm can alarm when other people use the telephone line to use a telephone illegal to remind users of notices and the users can use the telephone normally.

Description

The antitheft fault alarm of telephone wire

Affiliated technical field

The utility model relates to the antitheft fault alarm of a kind of telephone wire.

Background technology

Phone has become a necessity in people's daily life, but because in some living quarterss, design unreasonable, many telephone wires are that open-wire line is installed, opportunity has been arranged for like this some lawless persons, they can come free call on somebody else's expense through illegal means with the extension telephone machine, and real user will sustain a loss.

Summary of the invention

The purpose of this utility model is to provide a kind of telephone wire antitheft fault alarm, and it can send chimes of doom when others' phone combined with other handset and illegally used is arranged, call user's attention, and user oneself still can normally use when using phone.

The utility model comprises voltage detecting circuit, phonation circuit and relay, it is characterized in that: the input end of voltage detecting circuit is connected with the input end that local network is input to subscriber's telephone line, and the output terminal of voltage detecting circuit is connected with phonation circuit; Be connected to an end of subsets behind relay control coil of wherein any wire serial connection of described local network telephone wire input end, single line is directly connected to an other end of subsets in addition; The normally opened contact of relay is connected with the output terminal of voltage detecting circuit, and the armature contact of relay is connected with the ground of circuit.

Remarkable advantage of the present utility model is: easy to use, anti-free call on sb. else's expense through illegal means is effective, and does not influence user's normal use.

Description of drawings

Fig. 1 is the theory diagram of the utility model embodiment.

Fig. 2 is the circuit diagram of embodiment of the present utility model.

Embodiment

The principle of work of the utility model embodiment.

The incoming line two ends DC voltage of 50V of having an appointment has voltage on the R4 when user's telephone set on-hook, makes the BG1 saturation conduction, and BG2 ends, and the integrated music IC circuit loudspeaker of not working are noiseless.

When if outside line is connect free call on sb. else's expense through illegal means steathily by others, line voltage distribution descends during off-hook, and R4 voltage is not enough, makes BG1 end, the BG2 saturation conduction, and integrated music IC circuit is started working, and loudspeaker can send chimes of doom, send chimes of doom, call user's attention.

And when this machine of user oneself was made a phone call, behind the off-hook, relay work promptly made BG1 collector and emitter short circuit to make the integrated music circuit not work, alarm free sound.

Claims

1, the antitheft fault alarm of a kind of telephone wire, comprise voltage detecting circuit, phonation circuit and relay, it is characterized in that: the input end of voltage detecting circuit is connected with the input end that local network is input to subscriber's telephone line, and the output terminal of voltage detecting circuit is connected with phonation circuit; Be connected to an end of subsets behind relay control coil of wherein any wire serial connection of described local network telephone wire input end, single line is directly connected to an other end of subsets in addition; The normally opened contact of relay is connected with the output terminal of voltage detecting circuit, and the armature contact of relay is connected with the ground of circuit.