CN202183146U

CN202183146U - Magnetic alarm device of door

Info

Publication number: CN202183146U
Application number: CN2011203379469U
Authority: CN
Inventors: 范晓枫; 胡建春; 陈永兵
Original assignee: JIANGSU ZHONGXUN DIGITAL ELECTRONIC CO Ltd
Current assignee: JIANGSU ZHONGXUN DIGITAL ELECTRONIC CO Ltd
Priority date: 2011-09-09
Filing date: 2011-09-09
Publication date: 2012-04-04
Anticipated expiration: 2021-09-09

Abstract

The utility model discloses a magnetic alarm device of a door, which comprises a triggering circuit, and an alarm circuit and a magnet connected with the triggering circuit, wherein the triggering circuit is connected with a hall device which detects the magnetic field intensity of the magnet and transmits signals to the triggering circuit. A magnetic sensing device is adopted as the hall device to replace a reed pipe and detect the magnetic field change caused by increased distance between the magnet and the hall device after the door and a window are opened, and once the magnetic field intensity is detected to be smaller than a preset valve, the triggering circuit triggers the alarm circuit to give out an alarm.

Description

A kind of magnetic warning device

Technical field

The utility model relates to the security alarm field, or rather, relates to a kind of alarm triggering device that adopts hall device.

Background technology

A kind of important alarm triggering device in security alarm field (door magnetic) mainly is made up of tongue tube and magnet at present.Magnet and tongue tube are installed in respectively on door and doorframe or window and the window frame; When door or window are opened; The distance of tongue tube and magnet strengthens; Tongue tube can not obtain enough magnetic field and after recovering the work of magnet trigger circuit triggers door magnetic main body tongue tube, warning message launched with high frequency transmission circuit, and main frame is reported to the police by warning circuit after receiving alerting signal.

The tongue tube sheathing material is a glass, and brittle fracture lost efficacy; Sensitivity is on the low side, and the magnetic induction distance is short partially, particularly is installed on iron door, the window; Because iron plate has shielded the magnetic field of magnet, make the magnetic induction distance generally have only about 5mm, this is very high to the requirement of installing; Need be magnet near tongue tube, certain restriction that use occasion receives; The volume of tongue tube is bigger, is difficult to accomplish miniaturization; Can only be used for manual welding, can not mount automatically with chip mounter, efficient is low.

The utility model content

The utility model purpose: the utility model technical matters to be solved is the deficiency to prior art, and a kind of magnetic warning device is provided.

In order to solve the problems of the technologies described above; The utility model discloses a kind of magnetic warning device, comprise the warning circuit and the magnet of trigger circuit, connection trigger circuit, trigger circuit connect a hall device; Detect the magnetic field intensity of magnet by hall device, and transmit to trigger circuit.

In the utility model, said hall device is the nonpolarity Hall switch of TP4913.

In the utility model, said trigger circuit comprise the EM508P single-chip microcomputer.Can detect cell voltage, put and take pass, hall device etc. apart, in case detect door, window is opened and to be caused hall device to detect less than magnetic field, will trigger warning device work.

In the utility model, said warning circuit comprises PT4450 wireless transmit chip.Warning circuit is issued radio receiver to warning message through wireless signal and is realized reporting to the police; Also can be the wired alarming circuit, pass to wired receiving equipment to warning message through electric wire and realize reporting to the police; Also can be local warning circuit, realize reporting to the police through sounding, light light, unlatching electromechanical equipment etc.

In the utility model, the 1st pin ground connection of said nonpolarity Hall switch, the 3rd pin connects power supply, and the 2nd pin is out to leak the 7th pin of output connecting triggering circuit single-chip microcomputer, and the 2nd pin of single-chip microcomputer connects the 4th pin of wireless transmit chip.

The utility model adopts hall device as the magnetic induction device; The alternative dry reed pipe; Detect owing to causing the changes of magnetic field that the distance change causes greatly between magnet and the hall device after door, the window unlatching,, just report to the police by trigger circuit triggers in case detect magnetic field intensity less than setting value.Hall device in the utility model is generally selected non-polar hall ic for use; Its non-polar characteristic has reduced the installation requirement of magnet; Device inside is made up of timing circuit and amplifying circuit, and timing circuit makes amplifying circuit every at a distance from 100ms-200ms work several milliseconds times, detects the magnetic field intensity that Hall element is sensed; In case magnetic field is greater than or less than setting value, just export different state.Timing circuit can make the power consumption of device reduce greatly, to satisfy the requirement of adopting the long-term work of battery ability.Amplifying circuit can improve the sensitivity that detects magnetic field greatly, and the operating distance between magnet and the hall device is reached about 2CM, has application scenario widely.

Beneficial effect: the utility model adopts hall device as the magnetic induction device; The alternative dry reed pipe; Detect owing to causing the changes of magnetic field that the distance change causes greatly between magnet and the hall device after door, the window unlatching,, just report by trigger circuit triggers in case detect magnetic field intensity less than setting value.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the utility model is done specifying further, the above-mentioned and/or otherwise advantage of the utility model will become apparent.

Fig. 1 is the utility model structural representation.

Fig. 2 is the circuit theory diagrams of the utility model.

Embodiment

As shown in Figure 1; The utility model discloses a kind of alarm triggering device that adopts hall device, comprise the warning circuit 2 and the magnet 3 of trigger circuit 1, connection trigger circuit, trigger circuit connect a hall device 4; Detect the magnetic field intensity of magnet by hall device, and transmit to trigger circuit.In case magnetic field intensity is lower than detection threshold, just trigger single-chip microcomputer, send coded signal by single-chip microcomputer and give radio transmitter, pass to the reception main frame to alerting signal.

As shown in Figure 2; A kind of embodiment of the utility model; Said employing hall device can adopt the nonpolarity Hall switch of TP4913 of Nanjing topology company, and single-chip microcomputer is the EM508P of Wuxi Hua Jing, and the wireless transmit chip of radio transmitter adopts the general sincere PT4450 chip in Taiwan.

More particularly, the 1st pin ground connection of TP4913 is nonpolarity Hall switch U3, the 3rd pin connects the 3V power supply, and the 2nd pin draws resistance R 3 backs to link to each other with the 7th pin of single-chip microcomputer U1 for opening Lou output, connecting.When door, when window is closed, magnet is near hall device, and the detected magnetic field intensity of hall device is higher; The 2nd pin output electronegative potential of TP4913 is nonpolarity Hall switch U3, single-chip microcomputer U1 does not work, and the wireless transmit chip U2 of radio transmitter does not work yet; When door, when window is opened, magnet is away from hall device, and TP4913 is nonpolarity, and Hall switch U3 detects less than magnetic field; Its 2nd pin output high level triggers single-chip microcomputer U1 work, and gives the 4th pin of wireless transmit chip U2 through the 2nd pin outupt coded signal of single-chip microcomputer U1; The work of control radio transmitter passes to the reception background host computer to alerting signal.

The U1 chip is a 8 pin single-chip microcomputers, and model is BJ8P506, and its 1 pin is VDD; 8 pin are GND, and 7 pin are used to detect the signal of Hall switch TP4913 output for detecting pin; 2 pin are the coded signal output pin, export the work of 20 coded signal control radio transmitters.Its course of work is: U1 is in the standby dormant state at ordinary times, when Hall switch output high level is given 7 pin of U1 chip, and the wake-up trigger single-chip microcomputer, and export 8 groups of 20 coded signals, the work of control radio transmitter from 2 pin.

U2 is the wireless transmit chip, and model is PT4450, and 2 pin of U2 are GND, and 5 pin are VDD, and C2 and C3 are power filtering capacitor; The 1st, 6 pin of U2 are oscillatory circuit, and external 433.92M sound table resonator can produce the signal that frequency is 433.92M at chip internal, and capacitor C 5 is a sound table resonance matching capacitance with C5A; The 3rd pin of U2 is the output of RF signal, and through resonance, filtering circuit that external inductance L 1, L2, capacitor C 6, C7, C8, C9 form, launching intensity is the OOK signal of 10DBm.4 pin are control pin, and when high level is to transmit, low level is that standby quits work, owing to link to each other with 2 pin of single-chip microcomputer U1, launch the OOK wireless signal of 8 groups of 20 codings.

Workflow: the state that Hall switch U3 detecting gate, window are opened; Trigger single-chip microcomputer U1 work; Send 8 groups of 20 coded signals control wireless transmit chip U2 and transmit, emission finishes back U1 and U2 quits work, and waits for and being triggered by wireless transmit chip U3 next time.

Nonpolarity Hall switch U3 inside mainly is made up of current offset and temperature-compensation circuit, offset compensation circuit, oscillator box timing generator circuit, threshold values generator circuit, hall probe, chopper amplifier circuit, hysteresis comparator circuit, logic decision and latch cicuit, output circuit etc., and oscillator and sequential take place.

Nonpolarity Hall switch TP4913 is a nonpolarity Hall switch based on mixed signal CMOS technology, and this IC has adopted advanced chopped wave stabilizing technology, thereby accurate and stable magnetic switch point can be provided.

On circuit design; Nonpolarity Hall switch TP4913 provides an embedded controlled clock mechanism to come for hall device and analog signal processing circuit the clock source to be provided, and this controlled clock mechanism can be sent control signal and makes the bigger circuit period property ground of current sinking get into " dormancy " pattern simultaneously; Same through this mechanism, chip periodically " is waken up " and is passed the size of hall device magnetic field intensity according to being scheduled to the good magnetic field intensity threshold test external world.If magnetic flux density is higher than " operating point " threshold value or is lower than " point of release " threshold value, then opening Lou, output transistor is driven and latchs corresponding with it state.And in " dormancy " in the cycle, output transistor is locked under its previous state.In making battery-powered application, this design provides preferably support for prolonging battery service life.The output transistor of nonpolarity Hall switch TP4913 is the state of being locked in out when the South Pole that has certain intensity towards encapsulation sign one side or magnetic field, the arctic, and when no magnetic field, is locked in off status.

The utility model provides the thinking and the method for a kind of magnetic warning device; The method and the approach of concrete this technical scheme of realization are a lot, and the above only is the preferred implementation of the utility model, should be understood that; For those skilled in the art; Under the prerequisite that does not break away from the utility model principle, can also make some improvement and retouching, these improvement and retouching also should be regarded as the protection domain of the utility model.The all available prior art of each ingredient not clear and definite in the present embodiment realizes.

Claims

1. door magnetic warning device comprises trigger circuit, connects the warning circuit and the magnet of trigger circuit, it is characterized in that trigger circuit connect a hall device, detects the magnetic field intensity of magnet by hall device, and transmits to trigger circuit.

2. a kind of magnetic warning device according to claim 1 is characterized in that, said hall device is the nonpolarity Hall switch of TP4913.

3. a kind of magnetic warning device according to claim 2 is characterized in that said trigger circuit comprise the EM508P single-chip microcomputer.

4. a kind of magnetic warning device according to claim 3 is characterized in that said warning circuit comprises PT4450 wireless transmit chip.

5. a kind of magnetic warning device according to claim 4; It is characterized in that, the 1st pin ground connection of said nonpolarity Hall switch, the 3rd pin connects power supply; The 2nd pin is out to leak the 7th pin of output connecting triggering circuit single-chip microcomputer, and the 2nd pin of single-chip microcomputer connects the 4th pin of wireless transmit chip.