CN2898974Y

CN2898974Y - Magnetic sensor of safety alarming device

Info

Publication number: CN2898974Y
Application number: CN 200520116129
Authority: CN
Inventors: 蔡春良
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-10-19
Filing date: 2005-10-19
Publication date: 2007-05-09
Anticipated expiration: 2015-10-19

Abstract

A magnetic sensor of safety alarming device suitable for doors and windows, especially for sliding windows, comprising a magnetic switch and a signal conversion circuit, which changes the reverse signal of the switch state of the magnetic switch into the pulse signal and outputs. The sensor outputs no pulse signal at ordinary times, and outputs the pulse signal only when movement of the paired permanent magnet makes the switch state of the magnetic switch reverse. The window provided with the magnetic sensor has the safety alarming function, without losing the due ventilation function. The magnetic sensor has also multiple self-protection function, without being damaged even if being arranged in the place that can be reached by thieves. The magnetic sensor has simple structure and small volume. When being arranged, a plurality of magnetic sensors are connected with three wires by the parallel way to form a sensor output circuit, and the installment is extremely convenient. The magnetic sensor can be used in a plurality of doors and windows.

Description

The burglar alarm magnetic sensor

Technical field

The utility model relates to a kind of sensor, specifically is a kind of burglar alarm magnetic sensor and servicing unit thereof.

Background technology

At present home security is reported to the police and use sensor, and commonly used have two kinds of infrared sensor and magnetic switchs (magnetic).The scheme that alarm adopts usually is installed is: Passive Infrared Sensor is loaded onto at indoor important seat, adorns a door magnetic on the door, enter the room to be wiped by infrared sensor and survey in case the burglar gets over window, or door is pried open and causes a magnetic to disconnect, and alarm will be reported to the police.Can report to the police when the burglar is arranged though this scheme is indoor, have serious potential safety hazard.The burglar prizes window and goes into when the late into the night, and alarm equipment alarm is waken up with a start owner, and owner will head-on confrontation take place with the burglar unavoidably, so this scheme can not be brought the sense of security to owner.Desirable burglar alarm scheme should the burglar refuse outside window, alarm just should be reported to the police when promptly window was pried open by the burglar, reach this purpose must be on window sensor installation.

The burglar alarm sensor that can be used for window now mainly contains two kinds of magnetic switch and active infrared sensors.But these two kinds are all impracticable, active infrared sensor cost height, and reliability is low, and Installation and Debugging are difficult and easily destroyed; And magnetic switch is when alarm is set up defences, and all windows must be closed and lost the due draught effect of window.In addition, the latent fraud of installation magnetic switch is very poor on sliding window in a row, adds that magnetic switch self does not have the better protect function again, is destroyed by the burglar easily.

Summary of the invention

The purpose of this utility model provide be fit to door and window particularly sliding window install, the burglar alarm with multiple autoprotection function is with magnetic sensor and servicing unit thereof.

This burglar alarm is with magnetic sensor (abbreviation magnetic sensor) for achieving the above object; comprise magnetic switch, signaling conversion circuit, autoprotection circuit; servicing unit; it is characterized in that signaling conversion circuit is an impulse hits detecting device of being made up of logical circuit; the input of impulse hits detecting device connects magnetic switch, and output connects the autoprotection circuit.When the opening of magnetic switch (conducting) when closing that (ending), two states reversed mutually, signaling conversion circuit triggers alarm equipment alarm with regard to output pulse signal, output pulse signal has not so just brought dirigibility to practical application at ordinary times.

With the window is example, and magnetic sensor is installed on the fixed frame of window during practical application, and corresponding sash is adorned one.Permanent magnet is contained on the housing of sash, and each sash can be adorned one or two permanent magnets as required.The sash of only adorning a permanent magnet just has the warning effect when only being in the closed condition permanent magnet over against sensor, the sash that two permanent magnets are housed all has the warning effect when closing and opening this two states of certain width (being no more than 15 centimeters), because this two states all has a permanent magnetism over against sensor, or when promoting sash, the burglar passes through sensor.The sash of certain safer (burglar is difficult for patronizing or having taked other measure) is opened ventilation fully,, do not influence the warning function of whole other sash of warning system though this sash has lost the warning effect.

According to the different in kind of magnetic sensor output pulse, can be divided into two kinds of the electric current magnetic sensors of the voltage magnetic sensor of output voltage pulse and output current pulse.It is power input that the voltage magnetic sensor has three links, signal output part and earth terminal; It is power input and earth terminal that the electric current magnetic sensor has only two links.But the autoprotection function ratio electric current magnetic sensor of voltage magnetic sensor is strong.

Magnetic sensor is installed on the many sliding window housings in a row of sash, is difficult to accomplish that each sensor all is installed in the seat that the burglar can't touch.Destroy for anti-theft, magnetic sensor also has multiple autoprotection circuit, comprises the field effect transistor of pick-proof switch, vandal-proof protective wire, anti-off-line and pair magnetic switch of anti-external permanent magnet " deception " magnetic sensor.

A plurality of magnetic sensors should adopt mode in parallel to connect, load in mixture if these magnetic sensors all are voltage magnetic sensor or voltage magnetic sensor and electric current magnetic sensor, just needing to connect leads with three be that power lead, signal wire and ground wire connect into the sensor output loop; If all be the electric current magnetic sensor then only need two connecting lines, promptly power lead and ground wire connect into the sensor output loop.

Magnetic sensor volume simple in structure is little, can be processed into different shapes according to the specific requirement of different use occasions.

Based on the anti-servicing unit of usurping magnetic sensor, comprise transition and reverberator, the output of transition is connected to alarm, and input connects the sensor output loop, a transition can connect one or several sensor output loop as required, and reverberator is connected in the end of sensor output loop.

Transition is mainly by voltage detecting circuit, current detection circuit and signal transition circuit are formed, its effect mainly contains: 1, voltage or the transition of electric current alerting signal that the sensor output loop is sent here is the alerting signal output that alarm can be discerned, and triggers alarm equipment alarm.2, filtering interference signals.3, can send prompt tone output alarm signal the time and play the additional alarm effect.4, the loop of several sensors output is accumulated one tunnel output, reduced magnetic sensor with the connecting line between the alarm, the convenient installation.

The reference voltage source that has a high precision low temperature to float in the reverberator, its effect are to basic voltage of the output of the signal wire in the sensor output loop and base current, play protection sensor and output loop thereof and are not destroyed by the burglar.

Under multiple autoprotection circuit in magnetic sensor and filtrator, the reverberator synergy, magnetic sensor and output loop thereof possess good autoprotection function.No matter the burglar destroys magnetic sensor and output loop thereof with which kind of means, transition all can be exported one to alarm and trigger alerting signal, as long as transition and reverberator are installed in the seat that the burglar can't touch, magnetic sensor and output loop thereof just are mounted in the place that the burglar can touch also can't be destroyed.So magnetic sensor can use on the many sliding windows in a row of sash safely.

Description of drawings

Fig. 1 is voltage magnetic sensor circuit figure

Fig. 2 is electric current magnetic sensor circuit figure

Fig. 3 is the transition circuit diagram

Fig. 4 is reflector circuit figure

Embodiment

Below in conjunction with accompanying drawing the utility model is further specified.

Fig. 1 is the voltage magnetic sensor, and this sensor comprises magnetic switch, signaling conversion circuit and autoprotection circuit, and it is connected in the sensor output loop by three links, and these three links are+the 9.5V input end Signal output terminal and GND end respectively.

Magnetic switch SK1 plays a part to leave shutoff near the permanent magnet conducting.Under the effect of pull-up resistor R1, the counter-rotating of SK1 on off state can cause the saltus step of A level point height.Signaling conversion circuit comprises a reverser U1A and two OR circuit U2A, U2B and resistance R 2, R3 capacitor C 1, C2.Signaling conversion circuit of A level point height saltus step just produces a voltage pulse signal, exports from the Signal output terminal.

The autoprotection circuit comprises pick-proof switch S K2, protective wire S, field effect transistor Q1, Q2 and pair magnetic switch SK3.

The effect of pick-proof switch S K2 is to disconnect when magnetic sensor is prized.Protective wire S is wrapped in the periphery of magnetic sensor by low-melting thin wire with certain spacing, the outside surface inboard, and to be magnetic sensor destroyed or physical damage is a broken string with burning by the burglar in its effect.Pick-proof switch S K2 disconnects or the output of protective wire S broken string U2B becomes high level by low level, triggers alarm equipment alarm by transition.

Q1, Q2 are that N links up the MOS depletion field effect transistor, and its effect is whether three links that detect magnetic sensor are connected intact with three leads of its output loop.The grid of Q1 links to each other with+9.5V input end, and when having only this end off-line in three links, Q1 loses grid voltage and conducting absorbs certain electric current; The grid of Q2 links to each other with the Signal output terminal, and when having only this end off-line in three links, Q2 loses grid voltage and conducting absorbs certain electric current; When having only the off-line of GND end in three links, Q2 because of losing the conducting of screen voltage, changes the basic voltage of the signal wire that connects with the Signal output terminal by D3 equally.Therefore any one link off-line all can make the change signal of a curtage of magnetic sensor output, triggers alarm equipment alarm by transition, prevents that the burglar from utilizing the off-line method to make the magnetic sensor effect of can not bringing into normal play.

SK3 is for paying a magnetic switch, and its effect is burglar when wanting to utilize standby permanent magnet " deception " magnetic sensor, the triggering alarm equipment alarm.Pay magnetic switch SK3 and separate certain distance with magnetic switch SK1, it is inoperative that the magnetic field of permanent magnet that plays the warning effect at ordinary times tackles magnetic switch SK3, have only when the burglar takes standby permanent magnet near magnetic sensor and pay magnetic switch SK3 conducting, absorb certain electric current, trigger warning horn by transition and report to the police.

Fig. 2 is the electric current magnetic sensor, this magnetic sensor and voltage magnetic sensor are basic identical, its effect of element numbers components identical is also identical, and difference has: 1, the voltage pulse signal of signaling conversion circuit output converts current pulse signal output to by enhancement mode field effect transistor Q.2, have only two links to be respectively+9.5V input end and GND end.3, there is not link off-line holding circuit.So the electric current magnetic sensor is installed more convenient than voltage magnetic sensor, but does not have the off-line defencive function, can only be installed in the place that the burglar can't touch.The static working current that but increases this sensor possesses the off-line defencive function equally to certain value.

Fig. 3 is the transition circuit diagram, and this circuit comprises current detection circuit, voltage detecting circuit, transition circuit.The input interface of transition (+9.5V output terminal, Signal input end and GND end) is connected the sensor output loop, and it exports alarm to.

Whether the effect of current detection circuit is to detect the electric current that flows through inductance L to change.During the autoprotection circuit working of magnetic sensor, or can cause that all the electric current that flows through inductance L changes during its output current pulse alerting signal.The output terminal net1 of current detection circuit links to each other with an input end net1 of transition circuit.Operational amplifier U2B, U2C resistance R 7, R8, R9 form a bound voltage comparator, and bound voltage VA1, VB1 are symmetrically distributed in supply voltage central point both sides, and R8 regulates the degree of separation of bound voltage VA1, VB1.Operational amplifier U2A plays the signal amplification, regulates and exports the voltage near the supply voltage central point when R1 makes the input of U2A no signal.The signal that the inductance L self-induction produces is coupled to the in-phase input end of operational amplifier U2A through capacitor C 3, outputs to the input end of bound voltage comparator after U2A amplifies.When the input voltage of bound voltage comparator drops between bound voltage VA1, the VB1, the Net1 output low level; When input voltage exceeded bound voltage VA1, VB1, Net1 exported high level.Net1 just exports high level pulse when the electric current that flows through inductance L has the variation of certain intensity so have only.Regulate the sensitivity that detects electric current by regulating R6, R8, external interference is caused flow through the electric current of inductance L to change and can not make Net1 output high level pulse, just can make Net1 output high level pulse when having only magnetic sensor to send the alarm current signal here, obviously change intensity greater than the electric current that interference causes because the electric current of alerting signal changes intensity.

The effect of voltage detecting circuit is the change in voltage on the signal wire in the detecting sensor output loop.This circuit also is a bound voltage comparator of being made up of operational amplifier U3A, U3B resistance R 11, R12, R13, R14, and the Signal input end connects signal wire, and output terminal Net2 links to each other with another input end Net2 of transition.The adjustable reference voltage source (not drawing among the figure) that high precision low temperature floats provides a tunable center reference voltage ADJREF for the bound voltage comparator, requires the size of tunable center reference voltage ADJREF to equal the basic voltage of Singnal input end input.Bound reference voltage V A2, VB2 is distributed in the both sides of tunable center reference voltage ADJREF, when the voltage of Signal input end drops between bound reference voltage V A2, the VB2, Net2 output low level, Net2 output high level when exceeding.When voltage magnetic sensor work output voltage pulse signal, Net2 exports high level pulse.

For improve the sensitivity that the burglar reports to the police when destroying magnetic sensor and output loop thereof, difference between bound reference voltage V A2, the VB2 in the voltage detecting circuit is transferred to minimum, alerting signal and undesired signal from the input of Singnal input end all can make Net2 end output high level pulse like this, but the pulsewidth difference.

The effect of light emitting diode D7 has two: 1, indicating operating status, 2, the signal wire from the sensor output loop absorbs a base current, to increase the difficulty that the burglar wants to cut off sensor output loop connecting line and don't warning.

The main effect of transition circuit is the high level signal of current detection circuit and voltage detecting circuit output, is the trigger pip that alarm (generally adopting the telephone network alarm) can be discerned by relay R ELAY transition.

Above-mentioned current detection circuit itself possesses the effect of filtering undesired signal, so it directly triggers controllable silicon Q4 conducting by R20 from the high level signal of Net1 output, at this moment, the base stage of triode Q1 flows through a base current and conducting by R15, C5, Q4, relay R ELAY adhesive, the alarm output terminal is to trigger pip of alarm output, and hummer BUZZER sends prompt tone simultaneously.(a few second) Q1 ends when the C5 charging finishes, and Q4 ends thereupon, and relay discharges.R16 plays the slow discharge process of C5, plays C5 rapid discharge effect during field effect transistor Q2 conducting.

The high level signal of above-mentioned voltage detecting circuit Net2 output just can trigger controlled half a step Q4 conducting through D12, R20 by the time-delay filtrator of being made up of R17, C6, D11 again if trigger alerting signal; If undesired signal just can not be by the time-delay filtrator.Because the pulse width that triggers alerting signal is obviously greater than the pulse width of undesired signal.Conducting C6 rapid discharge when field effect transistor Q3 is low level at the Net2 input end, the filtrator of avoiding delaying time can not the continuous disturbing pulse signal of filtering.

Shutoff made field effect transistor Q2 be in cut-off state all the time when switch S K was flat, when opening when normally whether routine detects each magnetic sensor, needed only Net2 this moment and held high level Q2 with regard to conducting.Magnetic sensor is detected (opening sash in turn) in turn,, can hear that all hummer BUZZER sends prompt tone, need not wait the C5 discharge, conveniently sensor is detected as long as normally all can send the high level pulse signal here.

When transition shown in Figure 3, when connecting a plurality of sensor output loop that contains the voltage magnetic sensor simultaneously, need the voltage detecting circuit (only having drawn among the figure) of corresponding number.The input end of each voltage detecting circuit connects with separately signal wire, and the Net2 input end that crosses circuit is taken in output jointly, and electric current inspection circuit can each sensor output loop shared one.

Fig. 4 is reflector circuit figure, and it is connected in the end of sensor output loop, comprises reference voltage source D1, D2 that a high precision low temperature floats, divider resistance R1, R2, R3, R4, voltage follower UA.Its effect is to provide a basic voltage to the signal wire that is connected with the Signal output terminal.Adjusting R3 can change the size of basic voltage.Basic voltage should be adjustable in certain scope, the each household warning system of installing like this, and the basic voltage of its sensor output loop signal wire is just inequality, increases the difficulty that the burglar destroys.

If what connect in certain sensor output loop is the electric current magnetic sensor entirely, so, the end of this sensor output loop does not just need reverberator, but the quiescent current of last sensor is wanted enough big (several milliamperes), just can guarantee burglar's alarm equipment alarm when any seat cut-out connecting line of this sensor output loop.

Claims

1, a kind of burglar alarm magnetic sensor comprises magnetic switch, signaling conversion circuit, autoprotection circuit, and servicing unit is characterized in that signaling conversion circuit is an impulse hits detecting device of being made up of logical circuit.

2, burglar alarm magnetic sensor according to claim 1 is characterized in that the input of impulse hits detecting device connects magnetic switch, and output connects the autoprotection circuit.

3, burglar alarm magnetic sensor according to claim 1 is characterized in that the autoprotection circuit comprises pick-proof switch S K2, protective wire S, field effect transistor Q1, Q2 and pair magnetic switch SK3.

4, burglar alarm magnetic sensor according to claim 1, it is characterized in that servicing unit comprises transition and reverberator, the output of transition is connected to alarm, input connects the sensor output loop, reverberator is connected in the end of sensor output loop, transition is mainly by voltage detecting circuit, and current detection circuit and signal transition circuit are formed, the reference voltage source that has a high precision low temperature to waft in the reverberator.