CN2291685Y - Burglar alarm - Google Patents

Abstract

The utility model discloses a burglar alarm, which belongs to the technical field of alarms, composed of a casing 1, a buzzer 2, an alarming control circuit 3, a power supply 4, a switch of the power supply and an anti-theft sensor 6. The utility model is characterized in that the alarming control circuit is composed of a switching circuit, a voltage division resistor R < 2 >, a regulator and a current-limiting resistor R < 1 >; the ratio of the voltage division resistor R < 2 > and the resistor R of the anti-theft sensor equals to the ratio of the initial voltage of switching tubes Q < 2 >, Q< 3 > and the conducting initial voltage of a switching tube Q < 1 >. The utility model has the advantages of simple circuits, reliability, electricity saving and low cost; though destroyers pinch wires, a door is opened, and the burglar alarm has a short circuit, the utility model can send out alarms.

Description

Burglar alarm

The utility model relates to a kind of burglar alarm, belongs to the alarm technique field.

Existing alarm, the one, complex structure, the 2nd, power consumption is big, and the 3rd, the cost height, what have is too simple, and poor reliability especially is not suitable for family and uses.

The utility model purpose provides a kind of simple in structure, and cost is low, the burglar alarm that reliability is big.

Burglar alarm of the present utility model reaches by the following technical programs.This alarm comprises shell 1, news Chinese percussion instrument 2, and alarm control circuit 3, power supply 4, power switch 5, theft-proof sensor 6, its special character be, described alarm control circuit 3 is by controllable silicon SCR, triode Q ₁, Q ₂, Q ₃The on-off circuit of forming, divider resistance R ₂, voltage stabilizer and current-limiting resistance R ₁The voltage of forming voltage stabilizer is slightly less than the conducting starting potential of on-off circuit and divider resistance R ₂Should equal resistance R with the ratio of the resistance R of theft-proof sensor ₂Corresponding switching tube Q ₂, Q ₃The switching tube Q that the conducting starting potential is corresponding with resistance R ₁The ratio of conducting starting potential guarantees that on-off circuit is not worked under the normal condition, and alarm is not reported to the police.Controllable silicon SCR is connected between positive source and the news Chinese percussion instrument 2, triode Q ₁Emitter and after positive source joined, the control utmost point by its collector and controllable silicon SCR joined; Triode Q ₂Collector and after positive source joins, its emitter and triode Q ₃Emitter join, and by triode Q ₃Collector and the control utmost point of controllable silicon SCR join; Triode Q ₁, Q ₂Base stage be connected to the B point mutually, then, again by divider resistance R ₂With triode Q ₃Base stage be connected to the C point mutually; Be the theft-proof sensor 6 of R by the lead series resistor between B point and positive source, voltage stabilizer one end and positive source join, the other end and triode Q ₃Base stage join, and by current-limiting resistance R ₁Be connected on the power cathode.The B point is the potential balance point of on-off circuit like this, and 2 of C, A are the reference point of two current potentials up and down.Its fundamental diagram as shown in Figure 2.Energized K switch (being switch 5), electric current flows into power cathode by positive source here behind voltage stabilizer (being stabilivolt) and current-limiting resistance R1.Because the dividing potential drop effect of divider resistance R2 and theft-proof sensor R guarantees that three triodes all are in cut-off state.When the duty of theft-proof sensor changed, the resistance that B, A are 2 was that zero (resistance R is connected in parallel on the normally closed contact of switch, and as shown in Figure 6), at this moment, the voltage of voltage stabilizer all is added in divider resistance R ₂On, make triode Q ₂, Q ₃Conducting, Q ₃Collector signal output is arranged and triggers the controllable silicon SCR conducting, make news Chinese percussion instrument work and report to the police; Or at this moment the resistance of 2 of B, A flow through R for infinitely great (resistance R is connected on the normally opened contact of switch) ₂Electric current all pass through Q ₁Base stage, make triode Q ₁Conducting and trigger the controllable silicon SCR conducting, SCR makes news Chinese percussion instrument work and reports to the police, as long as power switch K does not turn-off, the news Chinese percussion instrument will continue to send chimes of doom, and no matter whether the lead-in wire of theft-proof sensor is destroyed, whether the working sensor state restores.

Voltage stabilizer of the present utility model can be a stabilivolt, also can be the ordinary silicon diode, and circuit is worked under little current status.The voltage stabilizing value of existing little electric current stabilivolt is volt all 〉=6, must the above power supply of 9V, and such operating voltage generally will provide by AC/DC changeover switch, the price height, in case power failure, alarm is ineffective.If use the stabilivolt of voltage stabilizing value＜6 volts, working current is big, generally is several milliamperes to tens milliamperes, and as if using dry cell power supply, loss is too fast, therefore, also needs AC/DC changeover switch that working power is provided.If utilize the forward conduction function of silicon diode, as voltage stabilizer, circuit is worked under tens microamperes of current status it, only get final product with above No. 5 batteries of three joints, greatly reduce cost, the usable range of alarm is increased, particularly can promote in family.

A kind of embodiment preferably of the utility model is, at triode Q ₁, Q ₂Base stage between the serial connection diode D ₄, be equivalent to increase triode Q like this ₁Initial operating voltage, be convenient to regulate resistance R ₂, R resistance.

The utility model another kind embodiment preferably is, at triode Q ₁, Q ₂Base stage between be connected in series a diode D again ₅At this moment R ₂Resistance greater than the resistance of R.

The utility model another preferably embodiment be, at triode Q ₃Base stage and tie point C between be connected in series a diode D ₆Be equivalent to increase triode Q like this ₂, Q ₃Initial operating voltage.

The utility model another preferably embodiment be divider resistance R ₂Resistance preferably equate with the interior resistance R resistance of theft-proof sensor, can increase work efficiency like this, reduce production costs.

The utility model another preferably embodiment be that voltage stabilizer is the ordinary silicon diode.Can reduce cost greatly like this.The number of diode is relevant with the conducting starting potential of switch triode.That is, must guarantee that the voltage stabilizing value of voltage stabilizer is slightly less than the initial operating voltage of conducting of on-off circuit.

Because burglar alarm of the present utility model adopted above-mentioned solution, make it compared with prior art, have simple in structurely, it is reliable to report to the police, as long as powered-down not, warning can be carried out for a long time, till the operator on duty cuts off the electricity supply.And after adopting the ordinary silicon diode to make voltage stabilizer, can make it when early warning, be operated in little current status, and saved electric energy, reduced cost, very suitable universal in the family.

Provide embodiment of the present utility model below in conjunction with accompanying drawing, be used for further specifying the utility model.

The structural representation of Fig. 1-burglar alarm;

The circuit theory diagrams of an embodiment of Fig. 2-burglar alarm;

The circuit theory diagrams of another embodiment of Fig. 3-burglar alarm;

The circuit theory diagrams of the 3rd embodiment of Fig. 4-burglar alarm;

The circuit theory diagrams of the 4th embodiment of Fig. 5-burglar alarm;

A kind of structural representation of Fig. 6-theft-proof sensor;

The another kind of structural representation of Fig. 7-theft-proof sensor.

Wherein: 1-shell, 2-news Chinese percussion instrument, 3-alarm control circuit, 4-power supply, 5-switch, 6-theft-proof sensor, 7-lead-in wire, 8-push rod, 9-depression bar, 10-shell, 11-binding post.

Embodiment 1, with reference to figure 1, Fig. 2, Fig. 6.This is that a theft-proof sensor is a structure shown in Figure 6, and voltage stabilizer is the alarm of stabilivolt, and except that theft-proof sensor 6 and lead-in wire 7, news Chinese percussion instrument 2, alarm control circuit 3, battery 4, switch 5 all are placed on the shell 1.Sensor thoroughly does away with A, the B point that edge lead (i.e. lead-in wire) is connected to alarm with two.The voltage stabilizing value of stabilivolt DW is slightly less than the conducting starting potential of on-off circuit, promptly is slightly less than triode Q ₁, Q ₂, Q ₃Be knot conducting starting potential sum; And resistance R ₂With the ratio of comparison resistance R be (Q ₂, Q ₃Be knot conducting starting potential): Q ₁Be knot conducting starting potential.Be R ₂Resistance be 2 times of (R of R resistance ₂=16K, R=8K).Principle of work is, in monitored chamber (as resident family's hut downstairs), theft-proof sensor 6 is installed, during installation, with theft-proof sensor be installed in indoor can with doorframe that door contacts on, the alarm main frame is placed in the duty room (as the resident family bedroom), K switch places the state that closes, after monitored chamber door is closed, door is given depression bar 9 one pressure of sensor, depression bar 9 disconnects normally closed contact by push rod 8, at this moment is connected in parallel in the resistance R line attachment on the contact, and the resistance that makes 2 of B, A is R, the voltage stabilizing value of stabilivolt DW is by resistance R ₂, the R dividing potential drop, the voltage between CB, the BA is in equilibrium state, the triode Q of on-off circuit ₁, Q ₂, Q ₃All be in cut-off state, news Chinese percussion instrument 2 is not reported to the police, and because of current-limiting resistance R ₁Resistance is big (20K), and entire circuit is in little current work state.When opening the door of monitored chamber, door is applied to the pressure of depression bar 9 and removes, and normally closed contact is connected, and makes 2 short circuits of B, A, and at this moment the voltage that provides of voltage stabilizer all drops on resistance R ₂On, the voltage that CB is 2 is greater than triode Q ₂, Q ₃Initial forward voltage, two the pipe conductings, Q ₃Collector electric current output is arranged and triggers the control utmost point of controllable silicon SCR, make the SCR conducting, the news Chinese percussion instrument is in running order and send chimes of doom.If the saboteur nips off lead-in wire, then 2 resistance of BA are ∞., flow through triode Q ₁Electric current increase, make its conducting, and trigger the controllable silicon conducting and make the news Chinese percussion instrument send chimes of doom.If be not related to cut-off electricity power supply, then continue its alarm condition, thereby reached the warning purpose.Because voltage stabilizer has adopted stabilivolt, so the loss of power is bigger.

Embodiment 2, with reference to figure 1, Fig. 3, Fig. 7.This is that a theft-proof sensor is a structure shown in Figure 7, the alarm that voltage stabilizer is served as by three silicon diodes.Compare with embodiment 1, difference is, the resistance R of theft-proof sensor is serially connected on the normally opened contact, and voltage stabilizer is made of three diodes series connection.At triode Q ₁, Q ₂Be connected in series a diode D between the base stage ₄, the initial operating voltage of on-off circuit is increased.Press because the voltage stabilizing value of voltage stabilizer is the forward conduction of three silicon diodes, be about 1.8V, and the conducting starting potential of on-off circuit is about 2.0V, meet the condition that stabilivolt voltage stabilizing value is slightly less than on-off circuit conducting starting potential.Again because Q ₂, Q ₃The conducting starting potential and the Q of be knot ₁Be knot, D ₄Conducting starting potential value equate, so R ₂=R.Power supply is No. 5 batteries of 1.5 volts at three joints.Principle of work is identical with embodiment 1.Its advantage is, because of R ₂=R is so make simple; Because of voltage stabilizer is that three silicon diode serial connections form, thus can make entire circuit be operated in little current status of tens microamperes, power saving, but save No. 5 battery continuous workings more than three months with three.

Embodiment 3, with reference to figure 1, Fig. 4, Fig. 7.Compare with embodiment 2, at the triode Q of on-off circuit ₁, Q ₂Be connected in series a diode D between the base stage again ₅, voltage stabilizer has been connected in series a diode D again on the basis of former three diodes ₇The voltage stabilizing value of voltage stabilizer (diode is a silicone tube) is 2.4 volts, and the initial operating voltage of on-off circuit is 2.5 volts, Q ₁Be knot conducting starting potential adds D ₄Conducting starting potential (about 1.0V) is less than D ₅, Q ₂Be knot, Q ₃Be ties conducting starting potential (about 1.5V).Therefore, R ₂: R=1.5: 1.0=3: 2.If R ₂Resistance is 15K, and then the R resistance is 10K.Principle of work is identical with embodiment 2.Compare R with embodiment 2 ₂Different with the R resistance, to make more numerously relatively, power consumption is bigger.

Embodiment 4, with reference to figure 1, Fig. 5, Fig. 6.This example is compared with embodiment 1, at triode Q ₁, Q ₂Two diode D have been connected in series between the base stage ₄, D ₅, at triode Q ₃Be connected in series a diode D between base stage and the C point ₆, the conducting starting potential of on-off circuit is raise, promptly increased the conducting starting potential of three diodes.And, R ₂: R=(D ₅, Q ₂Be knot, Q ₃Be knot, D ₆The conducting starting potential): (Q ₁Be knot, D ₄The conducting starting potential)=2: 1, if R is 8K, then R ₂Be 16K.Compare with embodiment 1, the voltage stabilizing value increases, and power consumption increases.

Claims (6)

1, a kind of burglar alarm, it comprises shell (1), news Chinese percussion instrument (2), alarm control circuit (3), power supply (4), power switch (5), theft-proof sensor (6) is characterized in that, described alarm control circuit (3) is by controllable silicon SCR, switch triode Q ₁, Q ₂, Q ₃The on-off circuit of forming, divider resistance R ₂, voltage stabilizer and current-limiting resistance R ₁Form, the voltage of voltage stabilizer is slightly less than the conducting starting potential of on-off circuit, and divider resistance R ₂Should equal resistance R with the ratio of the resistance R of theft-proof sensor ₂Corresponding switching tube Q ₂, Q ₃The switching tube Q that the conducting starting potential is corresponding with resistance R ₁The ratio of conducting starting potential, controllable silicon SCR are connected between positive source and the news Chinese percussion instruments (2), triode Q ₁Emitter and after positive source joined, the control utmost point by its collector and controllable silicon SCR joined triode Q ₂Collector and after positive source joins, its emitter and triode Q ₃Emitter join, and by triode Q ₃Collector and the control utmost point of controllable silicon SCR join triode Q ₁, Q ₂Base stage be connected to the B point mutually, then, again by divider resistance R ₂With triode Q ₃Base stage be connected to the C point mutually, between B point and positive source by the lead-in wire series resistor be the theft-proof sensor (6) of R, voltage stabilizer one end and positive source join, the other end and triode Q ₃Base stage join, and by current-limiting resistance R ₁Be connected on the power cathode.

2, by the described burglar alarm of claim 1, it is characterized in that, at triode Q ₁, Q ₂Base stage between be connected in series a diode D ₄

3, by the described burglar alarm of claim 2, it is characterized in that, at triode Q ₁, Q ₂Base stage between be connected in series a diode D again ₅

4, by the described burglar alarm of claim 3, it is characterized in that, at triode Q ₃Base stage and tie point C between be connected in series a diode D ₆

By the described burglar alarm of claim 2, it is characterized in that 5, the resistance R on the described theft-proof sensor equals divider resistance R ₂Value.

By claim 2 or 3 described burglar alarms, it is characterized in that 6, described voltage stabilizer is a general-purpose diode forward conduction voltage stabilizer.

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