CN2852144Y

CN2852144Y - Cable burglar alarm

Info

Publication number: CN2852144Y
Application number: CN 200520092394
Authority: CN
Inventors: 何首贤; 邢迎春; 张晶; 张风海; 马振峰
Original assignee: 何首贤
Priority date: 2005-09-04
Filing date: 2005-09-04
Publication date: 2006-12-27
Anticipated expiration: 2015-09-04

Abstract

The utility model relates to a cable burglar alarm which is characterized in that a cable loop which is measured is connected with a measuring circuit; a direct current power supply is connected with the cable loop and the measuring circuit; a signal output terminal of the measuring circuit is connected with a control circuit; the output of the control circuit drives a wired or wireless alarm circuit. The utility model has the characteristics that a cable is connected with the measuring circuit, electricity is supplied by the direct current power supply, therefore the cable can be equivalent into a pure resistor over the ground; the variation of the resistance of the measuring circuit reflects the conditions of a street lamp cable; the structure is simple, and the performance is reliable; the utility model adopts a wired or wireless alarming mode to directly return to a real-time monitoring terminal, and people can discover that the street lamp cable is stolen in time and can prevent the street lamp cable from being stolen in time.

Description

Anti-theft alarm for cable

Technical field the utility model relates to a kind of warning device, particularly a kind of road lighting cable burglar alarm.

The stolen case of road lighting cable happens occasionally in the background technology city, not only destroys urban public utilities, has influence on illumination, also can cause traffic hazard indirectly, even the harm personal safety.At present, do not retrieve the relevant relevant report that road lighting cable is stolen that prevents.

The summary of the invention the purpose of this utility model is to provide a kind of can prevent effectively that cable is stolen and simple in structure, the anti-theft alarm for cable of dependable performance.

The purpose of this utility model is achieved in that a kind of anti-theft alarm for cable, it is characterized in that tested cable loop is connected in the metering circuit, the power supply that is connected cable loop and metering circuit is a direct supply, the signal output part of metering circuit is connected with control circuit, and control circuit output drives wired or wireless warning circuit.

Tested cable is connected with metering circuit by the two-way contact by the relay of delay circuit control.

End at tested cable can perception in parallel or resistive load.

The bridge circuit of metering circuit for being connected and composed by resistance, tested cable is connected on the brachium pontis.

Also include display circuit, its input end is connected with the output terminal of metering circuit.

The utility model is to report to the police by the change in resistance realization of metering circuit, what metering circuit adopted is DC power supply, tested cable is connected in the metering circuit, cable over the ground between actual bulb, ballast resistor, trigger, the ac capacitor that connects, for direct current, its bulb and ac capacitor are equivalent to open circuit, are equivalent to only insert in metering circuit the equivalent resistance of ballast resistor and trigger like this, by the variation of monitoring cable resistance, just can in time find and prevent larceny.In order to improve the sensitivity of monitoring, can and connect transformer or resistance even load at cable end piece.The setting of delay circuit can be treated to be linked in the metering circuit after the discharge of tested cable loop again, prevents that residual electricity from causing the fluctuation of demonstration to the influence of metering circuit, guarantee the accuracy of measuring, showing.

Characteristics of the present utility model are: cable is connected in the metering circuit, and employing DC power supply, like this, cable can equivalence become pure resistance over the ground, the situation of the variation reflection road lighting cable by the metering circuit impedance, it is simple in structure, dependable performance, adopt wired or wireless type of alarm directly to feed back to the terminal of real-time monitoring, in time find and prevent that road lighting cable is stolen.

Description of drawings

Fig. 1 is a circuit block diagram of the present utility model;

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

Embodiment

The utility model is described in further detail below in conjunction with accompanying drawing:

As shown in Figure 1, 2, the road lighting cable burglar alarm mainly is made up of dc signal source, metering circuit, comparator circuit, control circuit, delay circuit and display circuit.Dc signal source is to be made of transformer, bridge rectifier circuit, filtering circuit, mu balanced circuit, and what wherein mu balanced circuit adopted is the regulator block of 7805 models.The loop that metering circuit comprises the resistance R 6, Rw1, R7 loop of serial connection, is made of contact J10-12, the J20-22 of diode VD6, the delay circuit relay that is connected with cable interface C, O and resistance R 8, R9 serial connection, adjustable resistance Rw1 in one loop is connected with display circuit, resistance R 8 in another loop is connected with comparator circuit with display circuit respectively by switch with the intermediate contact of resistance R 9, and two loops also connect formation bridge-type metering circuit.Diode in the metering circuit is used to prevent that alternating current from entering direct supply.The position of the two-way contact of figure repeat circuit is the state that alarm is in the access failure power supply.Comparator circuit is to be made of voltage comparator, the threshold voltage of one input end of voltage comparator for setting, another input end is connected with metering circuit, output terminal is connected with the switching tube of control circuit, the collector of switching tube is connected with relay J 4, contact J40, the J42 of relay or J41 can be connected with wired alarming output or radio alarming output, can send alerting signal to monitor terminal by wired or wireless.

The alarm energized, under the effect of delay circuit, cable is not linked in the metering circuit, is the discharge process of cable at this moment, and promptly the contact connected mode of relay goes out the position as solid line mark among the figure.After time-delay finished, relay tip switched, and connected mode is in the position of dotted line mark, and cable is linked in the metering circuit.If have the people to cut off cable this moment, the resistance in the bridge-type metering circuit changes, and comparator circuit output is connected the switching tube in the control circuit, sends alerting signal.

Claims

1, a kind of anti-theft alarm for cable, it is characterized in that tested cable loop is connected in the metering circuit, the power supply that is connected cable loop and metering circuit is a direct supply, and the signal output part of metering circuit is connected with control circuit, and control circuit output drives wired or wireless warning circuit.

2, anti-theft alarm for cable according to claim 1 is characterized in that tested cable is connected with metering circuit by the relay two-way contact by delay circuit control.

3, anti-theft alarm for cable according to claim 1, it is characterized in that can perception in parallel or resistive load at the end of tested cable.

4, anti-theft alarm for cable according to claim 1 is characterized in that metering circuit is the bridge circuit that is connected and composed by resistance, and tested cable is connected on the brachium pontis.

5, anti-theft alarm for cable according to claim 1 is characterized in that also including display circuit, and its input end is connected with the output terminal of metering circuit.