CN2177309Y

CN2177309Y - Anti-theft alarm for telephone

Info

Publication number: CN2177309Y
Application number: CN 93247018
Authority: CN
Inventors: 张连鸿
Original assignee: Individual
Current assignee: Individual
Priority date: 1993-12-03
Filing date: 1993-12-03
Publication date: 1994-09-14
Anticipated expiration: 2003-12-03

Abstract

The utility model relates to an anti-theft alarm for a telephone, which is characterized in that the alarm structure comprises a bleeder circuit which is composed of a resistor R1 and a resistor R2, a clad pipe which is composed o Q2, an NESS 555 oscillating circuit, and a Q3 status circuit which is composed of a triode Q3 and a cut-in user telephone set; a telephone line feeding voltage is connected with a base electrode of the Q1 after voltage dividing; the emitter electrode of the triode Q2 is connected with the power inputting terminal of the NE555 oscillating circuit; the oscillator signal outputting terminal of the oscillating circuit is connected with a vocal alarm and feeds in the speech wire through the capacitance C1. The base electrode, a collector, the emitter electrode of the triode Q3 are connected with a binding post of the telephone, and the base electrode of Q1 and the anode of the telephone line feeding voltage. The structure of the device is still oil saving, and is anti-theft for lines of a long-distance telephone and a city telephone.

Description

Anti-theft alarm for telephone

The utility model relates to a kind of telecommunications corollary equipment, particularly a kind of phone anti-theft warning device.

At present, phone progressively gos deep into family, whether user's telephone line is stolen, it is the problem that each user pays close attention to, existing long-distance lock words function is to be finished by the post office, needed interlocking telephone expenses usefulness in every month, and each conversation will be unblanked and shut, operation is complicated and can only lock long-distance call, and is inoperative to local telephone network.

The purpose of this utility model is that a kind of being attempted by of design talked about on the line, and except that the user, this words line of all uses all can in time give the alarm, and imports the phone anti-theft warning device that an interference signal can't be conversed it.

Task of the present utility model is done in such a way that its structure comprises the bleeder circuit that resistance R 1, R2 form, the multiple tube that triode Q1, Q2 form, NE555 oscillating circuit, the Q3 status circuit of forming with triode Q3 after substation inserts.Words line feed voltage joins with the base stage of triode Q1 after dividing potential drop, the power input of the emitter of triode Q2 and NE555 oscillating circuit joins, oscillator signal output is connected to the acoustic alarm device, and by C1 feed-in words line, the collector electrode of Q3 and the base stage of Q1 are joined, the emitter of Q3 joins with the positive pole of words line feed voltage, and the base stage of Q3 is the feed voltage input of substation.When the unmanned use of words line, Q3 is in cut-off state, and the feed voltage of words line is 48V, and this moment, triode Q1 base stage obtained high level through dividing potential drop, and triode Q1 is anti-inclined to one side, and multiple tube Q1, Q2 end, and the attention device non-transformer is not worked; When the words line is overlapped conversation by other people or disconnects, Q3 still locates cut-off state, words line feed voltage is reduced to 6V or 0V, and this moment, triode Q1 base stage obtained low level, at this moment triode Q1 positively biased, multiple tube Q1, Q2 conducting, the starting of oscillation of NE555 oscillating circuit is exported an oscillator signal and is promoted the warning of acoustic alarm device, and this signal is through capacitor C 1 feed-in words line simultaneously, make the ear-piercing vibration noise of appearance on this telephone line, can't converse; When user oneself used the words line, Q3 was in saturation condition, and words line feed voltage is reduced to 6V, because Q3's is saturated, makes the base stage of Q1 obtain the voltage of 6V, and triode Q1 is anti-inclined to one side, and multiple tube Q1, Q2 end, and the attention device non-transformer is not worked, and user's communication normally carries out.

The utlity model has power consumptive province simple in structure, and do not influence phone network work, all can in time send robber's telephone alarm and feed-in one interference signal, make and steal the function that words can't be carried out long-distance call and local telephone network.

Below in conjunction with legend the utility model is described further:

Fig. 1: schematic appearance

Fig. 2: circuit theory diagrams

With reference to Fig. 1: this is a phone anti-theft warning device schematic appearance, and circuit board etc. are fixed in the shell 1, on shell 1, be provided with words line feed voltage and introduce connector lug 2, and light-emitting diode 3, shell is by injection molded.

With reference to Fig. 2: form bleeder circuit by R1, R2, connect the base stage of triode Q1 after the dividing potential drop, export by the multiple tube that triode Q1, Q2 form, one the tunnel is connected to light-emitting diode, the power input of the oscillating circuit that another road and NE555 form joins, the oscillator signal output of oscillating circuit is connected to the acoustic alarm device, and by C1 feed-in words line, acoustic alarm can be selected loud speaker or piezo for use, and the base stage of triode Q3, collector electrode, emitter join with the base stage of phone binding post, Q1, the positive pole of words line feed voltage respectively.

Claims

1, a kind of phone anti-theft warning device, the structure that it is characterized in that attention device comprises resistance R 1, the bleeder circuit that R2 forms, the multiple tube that triode Q1, Q2 form, NE555 oscillating circuit, substation insert the Q3 status circuit of back and triode Q3 composition, words line feed voltage joins with the base stage of triode Q1 after dividing potential drop, the power input of the emitter of triode Q2 and NE555 oscillating circuit joins, and the output of oscillating circuit is connected to the acoustic alarm device, and by C1 feed-in words line.The base stage of triode Q3, collector electrode, emitter join with the base stage of phone binding post, Q1, the positive pole of words line feed voltage respectively.

2, phone anti-theft warning device according to claim 1 is characterized in that being connected to light-emitting diode on the emitter of triode Q2.

3, phone anti-theft warning device according to claim 1 is characterized in that the acoustic alarm device can select loud speaker or piezo for use.

4, phone anti-theft warning device according to claim 1 is characterized in that being connected to resistance R 6 between the emitter of triode Q3 and base stage, as the auxiliary channel of speech and ring.

5, phone anti-theft warning device according to claim 1 is characterized in that being provided with the phone binding post on the circuit board of attention device.