CN2689246Y

CN2689246Y - Circuit alarming devices

Info

Publication number: CN2689246Y
Application number: CN 200420010745
Authority: CN
Inventors: 董长富; 董海艳
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-04-29
Filing date: 2004-04-29
Publication date: 2005-03-30
Anticipated expiration: 2014-04-29

Abstract

The utility model discloses a line anti-theft alarm, composed of a plurality of resistors, a transistor, a relay, a digital instrument, an alarm device and a direct current power supply which are connected with each other. The line anti-theft alarm makes use of an electric bridge theory to operate, and when an electric line is accessed, the relay is disconnected if the line is electrified, and the anti-theft alarm is out of service; when the line is power-off, the contact of the relay is closed, and the anti-theft alarm operates by its own power supply, and can monitor the change of the resistance value of the resistor in the line from time to time and then sends alarm signals. The line anti-theft alarm is particularly applied to rural areas, most time of where are power off.

Description

Line burglar alarm

Technical field

The utility model belongs to the emergency protective circuit device, relates in particular to a kind of line burglar alarm.

Background technology

Rural area 400V drought resisting circuit electric power feeding time is limited at present, and this just cut power circuit to the offender robber and caused a lot of opportunities all at shut down condition about 3/4ths time.For running these circuits well, line disconnection, reinstall when needing electricity consumption when not electricity consumption in some rural area again, and this is the wasting manpower and material resources both, loses electrical lead again.Some is local carries out the patrol of whole day twenty four hours, but hundred close unavoidable one dredge, and the stolen phenomenon of power circuit still happens occasionally.Therefore, a kind of line burglar alarm that is adapted at using on the more circuit of rural area power failure of invention is a necessary job.

Summary of the invention

The purpose of this utility model provides a kind of line burglar alarm that can send alerting signal when circuit is cut under powering-off state.

For this purpose, the utility model adopts following technical scheme: a kind of line burglar alarm, and it comprises resistance R 1, R2 and variable resistor R3, an end of resistance R 1 is a free end, the other end and the R2 of R1 join, the other end of R2 and variable resistor R3 join, and the other end of R3 is a free end, and the positive pole of direct supply is connected between R1 and the R2, negative pole is connected on the free end of R3, digital instrument V links to each other with direct supply, and the debugging of digital instrument V terminates between R2 and the R3, and the working end is connected on the free end of R1; It also comprises two triode T1, T2 and three relay ZJ0, ZJ1, ZJ2, be connected on the free end of R1 behind pressure limiting resistance R X of base stage series connection of triode T1, the collector of T1 connects the positive pole of direct supply by relay ZJ1, the emitter of T1 connects the negative pole of direct supply, the base stage of triode T2 is connected between R2 and the R3, the collector of T2 connects the positive pole of direct supply by relay ZJ2, the free end of the emitter connecting resistance R1 of T2, relay ZJ0 are connected between the free end of the free end of R1 and R3; It also comprises warning device, warning device by and the relay ZJ1 that connects and ZJ2 the two poles of the earth of being connected on direct supply; It also comprises plurality of fixed resistance R Y, and in use, each fixed resistance RY is connected on the end of a protected circuit respectively.

Resistance R 1 equates with the resistance of R2.

Described warning device is a light alarming device.

Described warning device is a loudspeaker.

It also comprises relay ZJ3, and ZJ3 is connected on the two poles of the earth of direct supply, and the normally opened contact of ZJ3 links to each other with the normally closed contact of ZJ2.

Adopt the line burglar alarm of technique scheme, utilized electrical bridge principle work, after inserting power circuit, if circuit is charged, then relay disconnects, burglar alarm is not worked, when circuit cuts off the power supply, relay contact closure, burglar alarm relies on self power work, at any time the variation of resistance and send alerting signal in the Monitoring Line is particluarly suitable for the more rural area of power off time and uses.

Description of drawings

Figure is circuit theory diagrams of the present utility model.

Embodiment

As shown in the figure, this line burglar alarm comprises resistance R 1, R2 and variable resistor R3, and resistance R 1 equates with the resistance of R2.One end of resistance R 1 is a free end, the other end and the R2 of R1 join, the other end of R2 and variable resistor R3 join, and the other end of R3 is a free end, and the positive pole of direct supply is connected between R1 and the R2, negative pole is connected on the free end of R3, digital instrument V links to each other with direct supply, and the input end of digital instrument V is divided into debugging end and working end, and the debugging end is controlled by a double throw switch K1 with the working end, debugging end M is connected between R2 and the R3, and working end N is connected on the free end of R1; It also comprises two triode T1, T2 and three relay ZJ0, ZJ1, ZJ2, be connected on the free end of R1 behind pressure limiting resistance R X of base stage series connection of triode T1, the collector of T1 connects the positive pole of direct supply by relay ZJ1, the emitter of T1 connects the negative pole of direct supply, the base stage of triode T2 is connected between R2 and the R3, the collector of T2 connects the positive pole of direct supply by relay ZJ2, the free end of the emitter connecting resistance R1 of T2, relay ZJ0 are connected between the free end of the free end of R1 and R3; It also comprises warning device, warning device by and the relay ZJ1 that connects and ZJ2 the two poles of the earth of being connected on direct supply, warning device can be light alarming device HD, also can be loudspeaker FM; It also comprises plurality of fixed resistance R Y, and in use, each fixed resistance RY is connected on the end of a protected circuit respectively, for ease of judging that the resistance of each fixed resistance RY is all inequality.Between direct supply the two poles of the earth, also be connected on relay indicating light LD

When protected circuit has many; the free end of the free end of resistance R 1 and variable resistor R3 will join with all protected circuit simultaneously as the input end of burglar alarm; each protected circuit is state in parallel and inserts; what show in the drawings is the situation that four protected circuits are arranged; fixed resistance RY1, RY2, RY3, RY4 insert respectively in the protected circuit, and its resistance increases progressively to RY4 successively from RY1, RY2, RY3.

When the protection transformer, can seal in fixed resistance RY in the transformer secondary coil.

For guaranteeing safety, also comprise relay ZJ3 in the line burglar alarm, ZJ3 is connected on the two poles of the earth of direct supply, and the normally opened contact of ZJ3 links to each other with the normally closed contact of ZJ2.In addition, between digital instrument V and direct supply, be connected to a gauge tap K2.

Pressure limiting resistance R X is designed to the form of variable resistance box among the figure; its each grade resistance R X1, RX2, RX3, RX4 ... resistance successively decrease successively; and form corresponding relation with the resistance of fixed resistance RY; that is to say; when protected circuit was one, the RX1 that pressure limiting resistance is transferred in the resistance maximum was when protected circuit is two; pressure limiting resistance transfers to the slightly little RX2 of resistance, and the like.The effect of pressure limiting resistance is the all-in resistance in the regulating loop, thereby guarantees to work as circuit just often, and triode T1 is in cut-off state.

Relay ZJ0 is a high-voltage relay, when protected circuit is sent a telegram here, and relay ZJ0 action, its normally closed contact is opened, and makes the relay ZJ3 action that is attached thereto simultaneously, play double protection, thereby the protection circuit burglar alarm can not burnt out by high pressure.When protected circuit cuts off the power supply, relay ZJ0 action, its normally closed contact closure, and make the relay ZJ3 action that is attached thereto, line burglar alarm rearming.

Learn that from electrical bridge principle resistance R 1 and R2 constitute two arms of electric bridge, variable resistor R3 is another arm of electric bridge, and the all-in resistance of all protected circuits constitutes the 4th arm of electric bridge.

After circuit connects, the K2 that closes a switch earlier connects the power supply of digital instrument V, again K switch 1 is pushed debugging end M, regulate the resistance of variable resistor R3, make electric bridge reach balance, what at this moment digital instrument V showed is the voltage at variable resistor R3 two ends, because the all-in resistance in the circuit is a fixed value, the numerical value that shows behind the digital instrument V working stability also just is a determined value, and this determined value can be in advance by calculating.After debugging finishes, K switch 1 is pushed working end N get final product.When stolen or other open circuit conditions of circuit takes place,, broken the balance of electric bridge because the all-in resistance of protected circuit increases; triode T2 conducting; relay ZJ1 normally opened contact closure, warning that light alarming device is luminous, loudspeaker is sounded, the display digit of digital instrument V also will change.

Because the resistance of each fixed resistance RY is all inequality; like this; when different circuits open circuit; the all-in resistance of protected circuit becomes different numerical value, and the display digit of digital instrument V is also just different, can measure the display digit of digital instrument V under the different open circuit conditions in advance; when the generation circuit is stolen; just can make comparisons with the numerical value of measuring in advance, judge it is that problem has taken place which bar circuit rapidly, thereby handled as early as possible according to the numeral of digital instrument V actual displayed.

When artificial or accident is short-circuited when protected circuit, triode T2 conducting, protection digital instrument V is not burnt by high pressure, and digital instrument V display digit is zero, the relay ZJ2 closing of contact, warning that light alarming device HD is luminous, loudspeaker FM sounds.

After debugging finishes, can cut-off switch K2, digital instrument V is quit work, and when alerting signal is arranged Closing Switch K2 again, this can prolong the serviceable life of digital instrument V.

Claims

1, a kind of line burglar alarm, it is characterized in that: it comprises resistance R 1, R2 and variable resistor R3, one end of resistance R 1 is a free end, and the other end and the R2 of R1 join, and the other end of R2 and variable resistor R3 join, the other end of R3 is a free end, the positive pole of direct supply is connected between R1 and the R2, and negative pole is connected on the free end of R3, and digital instrument V links to each other with direct supply, the debugging of digital instrument V terminates between R2 and the R3, and the working end is connected on the free end of R1; It also comprises two triode T1, T2 and three relay ZJ0, ZJ1, ZJ2, be connected on the free end of R1 behind pressure limiting resistance R X of base stage series connection of triode T1, the collector of T1 connects the positive pole of direct supply by relay ZJ1, the emitter of T1 connects the negative pole of direct supply, the base stage of triode T2 is connected between R2 and the R3, the collector of T2 connects the positive pole of direct supply by relay ZJ2, the free end of the emitter connecting resistance R1 of T2, relay ZJ0 are connected between the free end of the free end of R1 and R3; It also comprises warning device, warning device by and the relay ZJ1 that connects and ZJ2 the two poles of the earth of being connected on direct supply; It also comprises plurality of fixed resistance R Y, and in use, each fixed resistance RY is connected on the end of a protected circuit respectively.

2, line burglar alarm as claimed in claim 1 is characterized in that: resistance R 1 equates with the resistance of R2.

3, line burglar alarm as claimed in claim 1 or 2 is characterized in that: described warning device is a light alarming device.

4, line burglar alarm as claimed in claim 1 or 2 is characterized in that: described warning device is a loudspeaker.

5, line burglar alarm as claimed in claim 1 or 2 is characterized in that: it also comprises relay ZJ3, and ZJ3 is connected on the two poles of the earth of direct supply, and the normally opened contact of ZJ3 links to each other with the normally closed contact of ZJ2.