方案概述

　　在一些安全等级非常高的应用场合，如保险库墙壁和门、夜间存款机等，需要多种方式监测其状态。无线振动报警器，可以在还未入侵时，检测如爆炸物和钻石尖钻头、机械和液压工具、 火焰切割机等工具造成振动的信号并及时告警。如何准确无误地探测振动信号?本方案使用灵敏的振动传感器与优秀的信号处理电路，低功耗电池供电，并通过无线传输方式将信息给监控中心，精准实现防盗预警。

　　优势

　　• 0.28um超薄压电薄膜传感器（LDT0-028K），无源器件方便布线，且可根据实际需求定制尺寸，方便安装。

LDT0-028K压电薄膜传感器

The LDT0-028K is a flexible componentcomprising a 28 µm thick piezoelectric PVDFpolymer film with screen-printed Ag-inkelectrodes, laminated to a 0.125 mm polyestersubstrate, and fitted with two crimped contacts.As the piezo film is displaced from themechanical neutral axis, bending creates veryhigh strain within the piezopolymer and thereforehigh voltages are generated. When the assemblyis deflected by direct contact, the device acts asa flexible "switch", and the generated output issufficient to trigger MOSFET or CMOS stagesdirectly. If the assembly is supported by itscontacts and left to vibrate "in free space" (withthe inertia of the clamped/free beam creatingbending stress), the device will behave as anaccelerometer or vibration sensor. Adding mass,or altering the free length of the element byclamping, can change the resonant frequencyand sensitivity of the sensor to suit specificapplications. Multi-axis response can beachieved by positioning the mass off center. TheLDTM-028K is a vibration sensor where thesensing element comprises a cantilever beamloaded by an additional mass to offer highsensitivity at low frequencies.

FEATURES

• Solder Tab Connection

• Both No Mass & With Mass Version

• Withstands High Impact

• Operating Temperature: 0ºC to 85ºC

• Storage Temperature: -40ºC to 85 ºC

• Higher Temperature Version up to 125 ºC available on a Custom Basis

APPLICATIONS

• Vibration Sensing in Washing Machine

• Low Power Wakeup Switch

• Low Cost Vibration Sensing

• Car Alarms

• Body Movement

• Security Systems

　　• 运行功耗仅64 μA/MHz，待机功耗1.4uA的超低功耗32位MCU（SI4438-C2A-GMR），延长报警器电池使用寿命。

【Si4438】

HIGH-PERFORMANCE, LOW-CURRENT TRANSCEIVER

Features

> Frequency range = 425–525 MHz

> Receive sensitivity = –124 dBm

> Modulation

》(G)FSK

》OOK

> Max output power

》+20 dBm

> Low active power consumption

》14 mA RX

> Ultra low current powerdown modes

》30 nA shutdown, 50 nA standby

> Data rate = 100 bps to 500 kbps

> Fast wake and hop times

> Power supply = 1.8 to 3.6 V

> Excellent selectivity performance

》58 dB adjacent channel

》75 dB blocking at 1 MHz

> Antenna diversity and T/R switch control

> Highly configurable packet handler

> TX and RX 64 byte FIFOs

> Auto frequency control (AFC)

> Automatic gain control (AGC)

> Low BOM

> Low battery detector

> Temperature sensor

> 20-Pin QFN package

> IEEE 802.15.4g ready

> China regulatory

Applications

> China smart meters

Description

Silicon Laboratories' Si4438 is a high-performance, low-currenttransceivers covering the sub-GHz frequency bands from 425 to525 MHz. The Si4438 is targeted at the Chinese smart meter market andis especially suited for electric meters. This device is footprint- andpin-compatible with the Si446x radios, which provide industry-leadingperformance for worldwide sub-GHz applications. The radios are part ofthe EZRadioPRO® family, which includes a complete line of transmitters,receivers, and transceivers covering a wide range of applications. Allparts offer outstanding sensitivity of –124 dBm while achieving extremelylow active and standby current consumption. The 58 dB adjacent channelselectivity with 12.5 kHz channel spacing ensures robust receiveoperation in harsh RF conditions. The Si4438 offers exceptional outputpower of up to +20 dBm with outstanding TX efficiency. The high outputpower and sensitivity results in an industry-leading link budget of 144 dBallowing extended ranges and highly robust communication links.

Functional Block Diagram

      【无线报警器】

　　无线报警器是探测电信号由空间电磁波传输的报警器。在某些防范现场很分散或不便铺设传输线的情况下，无线报警器才有独特之用。为了实现无线传输，必须在探测器和报警控制器之间，增加无线信道发射器和接收器。

　　简介

　　无线报警器是探测电信号由空间电磁波传输的报警器。在某些防范现场很分散或不便铺设传输线的情况下，无线报警器才有独特之用。为了实现无线传输，必须在探测器和报警控制器之间，增加无线信道发射器和接收器。

　　GSM无线电话报警器，充分利用公共电话网络与无处不在的GSM无线电话网，双网齐下，能与任何一款自动拨号报警系统配合使用，提供可靠性极高的信号传输服务，确保报警信号成功传输。它打破了报警系统的空间约束，在野外、海上等没有电话线的场所都将大派用场。

　　巡鹰GSM系列多功能GSM报警器G50B全球无线移动通讯网络控制报警主机利用全球GSM短信息数据传输模式及语音功能平台完成智能数据远程传输及控制报警，该主机集家庭、商店、办公场所安全，电器控制、私家车远方监控等智能家居功能为一体，由于GSM全球无线移动通讯网络信号覆盖面积广，真正实现了低价优质的超远距离方便、灵活的智能无线控制及报警，解决了固定电话或有线宽带网络有线报警的局限性。

　　工作原理

　　本报警系统利用GSM无线蜂窝电话网短信及语音功能平台完成远程报警数据传输及控制，系统可按主人设定的模式进行布防，当探测器探到入侵信号并把报警信号发送给主机，主机处理后向用户预先设好的手机号码发送有报警地址及类别的短信息，并自动拨打事先设好的1-3组电话号码进行语音报警并可对现场进行监听，另外用户可以通过远程发送短信方式对系统进行设防/撤防等远程操作。

　　网络覆盖

　　GSM全球无线移动通讯网络已在全世界普及，因此巡鹰PH-G系列多功能GSM报警器G50B全球无线移动通讯网络控制报警主机可广泛应用于单一家庭、小区物业、电力、交通、石油、煤炭、铁道、市政、公安等部门行业的安防装置、数据监测以及远程监控系统。