Piezoelectric motors are used in digital cameras for autofocus,zooming and optical image stabilization. Theyare relatively small, lightweight and effi cient, but theyalso require a complicated driving scheme. Traditionally,this challenge has been met with the use ofseparatecircuits, including a step-up converter and an oversizedgeneric full-bridge drive IC. The resulting high componentcount and large board space are especially problematicin the design of cameras for ever shrinking cell phones.The LT®3572 solves these problems by combining astep-up regulator and a dual full-bridge driver in a 4mm× 4mm QFN package. Figure 1 shows a typical LT3572Piezo motor drive circuit. A step-up converter is usedto generate 30V from a low voltage power source suchas a Li-Ion battery or any input power source within thepart’s wide input voltage range of 2.7V to 10V. The highoutput voltage of the step-up converter, adjustable upto 40V, is available for the drivers at the VOUT pin. Thedrivers operate in a full-bridge fashion, where the OUTAand OUTB pins are the same polarity as the PWMA andPWMB pins, respectively, and the OUTA and OUTB pinsare inverted from PWMA and PWMB, respectively. Thestep-up converter and both Piezo drivers have their ownshutdown control. Figure 2 shows a typical layout
For a variety of reasons, it is desirable to charge batteriesas rapidly as possible. At the same time, overchargingmust be limited to prolong battery life. Such limitation ofovercharging depends on factors such as the choice ofcharge termination technique and the use of multi-rate/multi-stage charging schemes. The majority of batterycharger ICs available today lock the user into one fixedcharging regimen, with at best a limited number ofcustomization options to suit a variety of application needsor battery types. The LTC®1325 addresses these shortcomingsby providing the user with all the functionalblocks needed to implement a simple but highly flexiblebattery charger (see Figure 1) which not only addressesthe issue of charging batteries but also those of batteryconditioning and capacity monitoring.
為了改變目前電網(wǎng)現(xiàn)場作業(yè)管理的變電巡檢、變電檢修試驗(yàn)、輸電線路巡檢檢修等管理系統(tǒng)各自獨(dú)立運(yùn)行，信息不能共享，功能、效率受限，建設(shè)和維護(hù)成本高的現(xiàn)狀，提出了采用B/S+C/S構(gòu)架模式，將各現(xiàn)場作業(yè)管理模塊和生產(chǎn)MIS（管理系統(tǒng)）集成為一體的現(xiàn)場作業(yè)管理系統(tǒng)的設(shè)計(jì)方案，做到各子系統(tǒng)和生產(chǎn)MIS軟硬資源共享，做到同一數(shù)據(jù)唯一入口、一處錄入多處使用。各子系統(tǒng)設(shè)備人員等基礎(chǔ)信息來源于生產(chǎn)管理系統(tǒng)，各子系統(tǒng)又是生產(chǎn)管理系統(tǒng)的作業(yè)數(shù)據(jù)、缺陷信息的重要來源。經(jīng)過研究試用成功和推廣應(yīng)用，目前該系統(tǒng)已在江西電網(wǎng)220 kV及以上變電站全面應(yīng)用。
Abstract:
In order to improve the status that the substation field inspection system， substation equipments maintenance and testing system， power-line inspection and maintenance system are running independent with each other. They can?蒺t share the resource information which accordingly constrains their functions and efficiency， and their construction and maintenance costs are high. This paper introduces a field standardized work management system based on B/S+C/S mode， integrating all field work management systems based on MIS and share the equipments and employee?蒺s data of MIS，the field work data of the sub systems are the source information of MIS， by which the same single data resouce with one-time input can be utilized in multiple places. After the research and testing， this system is triumphantly using in all 220kV and above substations in Jiangxi grid.
Analog Inputs and Outputs in an S7 PLC are represented in the PLC as a 16-bit integer. Over
the nominal span of the analog input or output, the value of this integer will range between -
27648 and +27648. However, it is easier to use the analog values if they are scaled to the
same units and ranges as the process being controlled. This applications tip describes
methods for scaling analog values to and from engineering units.
The MAX9257/MAX9258 programmable serializer/deserializer (SerDes) devices transfer both video data and control signals over the same twisted-pair cable. However, control data can only be transmitted during the vertical blank time, which is indicated by the control-channel-enabled output (CCEN) signal. The electronic control unit (ECU) firmware designer needs to know how quickly to respond to the CCEN signal before it times out and how to calculate this duration. This application note describes how to calculate the duration of the CCEN for the MAX9257/MAX9258 SerDes chipset. The calculation is based on STO timeout, clock frequency, and UART bit timing. The CCEN duration is programmable and can be closed if not in use.
針對目前使用的RS232接口數(shù)字化B超鍵盤存在PC主機(jī)啟動(dòng)時(shí)不能設(shè)置BIOS，提出一種PS2鍵盤的設(shè)計(jì)方法?；赪78E052D單片機(jī)，采用8通道串行A/D轉(zhuǎn)換器設(shè)計(jì)了8個(gè)TGC電位器信息采集電路，電位器位置信息以鍵盤掃描碼序列形式發(fā)送，正交編碼器信號(hào)通過XC9536XL轉(zhuǎn)換為單片機(jī)可接收的中斷信號(hào)，軟件接收到中斷信息后等效處理成按鍵。結(jié)果表明，在滿足開機(jī)可設(shè)置BIOS同時(shí)，又可實(shí)現(xiàn)超聲特有功能，不需要專門設(shè)計(jì)驅(qū)動(dòng)程序，接口簡單，成本低。
Abstract: Aiming at the problem of the digital ultrasonic diagnostic imaging system keyboard with RS232 interface currently used couldn?蒺t set the BIOS when the PC boot， this paper proposed a design method of PS2 keyboards. Based on W78E052D microcontroller，designed eight TGC potentiometers information acquisition circuit with 8-channel serial A/D converter， potentiometer position information sent out with keyboard scan code sequentially.The control circuit based on XC9536 CPLD is used for converting the mechanical actions of the encoders into the signals that can be identified by the MCU， software received interrupt information and equivalently treatmented as key. The results show that the BIOS can be set to meet the boot， ultrasound specific functionality can be achieved at the same time， it does not require specially designed driver，the interface is simple and low cost.
氣壓是氣象監(jiān)測中的一個(gè)重要參數(shù)，提出了一種氣壓數(shù)據(jù)采集模塊設(shè)計(jì)方案，該模塊采用數(shù)字氣壓傳感器MS5534B、MSP430單片機(jī)MSP430F2272和帶實(shí)時(shí)時(shí)鐘（RTC）64 KB鐵電存儲(chǔ)器。通過低功耗軟件設(shè)計(jì)方法以微安級(jí)整體平均功耗實(shí)現(xiàn)了氣壓數(shù)據(jù)的采集和存儲(chǔ)，適合電池供電的連續(xù)高精度氣壓采集應(yīng)用。給出了模塊的軟硬件設(shè)計(jì)以及MS5534B的性能指標(biāo)和使用經(jīng)驗(yàn)。
Abstract:
Air pressure is an important parameter in weather monitor.This paper futs forward a new design scheme of low power-air pressure data acquisition module.The module uses a digital output barometer sensor MS5534B,MSP430 microcontroller MSP430F2272 and integrated RTC 64KB FRAM,precision air pressure measurement and storage chip.Another point of this module is low power consumption, so it is well suited for battery powered air pressure data acquisition applications. At the same time,the software and hardware deign of module is presented,And the speciaties and use notices of MS5534B are given.
采用單片機(jī)AT89C2051實(shí)現(xiàn)溫度測量與控制,鍵盤和顯示電路實(shí)現(xiàn)溫度的設(shè)定、修改、清零以及當(dāng)前溫度值的顯示,并對溫度超過上下限進(jìn)行報(bào)警。闡述了該系統(tǒng)設(shè)計(jì)的硬件和軟件設(shè)計(jì)。
Abstract:
The system of temperature measuring and controling is realized based on AT89C2051.The keyboard and display circuit is designed,which can be used for setting and modifying temperature value,resetting and displaying the present temperature value.At the same time the warning circuit is also designed in the system,which can deal with the alarm when temperature exceeds the upper limit and the lower limit.The hardware and software design of the system are explained．
針對眾多低成本數(shù)據(jù)采集需求，采用帶有片上USB控制器和D/A轉(zhuǎn)換器的混合信號(hào)微處理器C8051F340，設(shè)計(jì)了一款可通過USB接口和LabVIEW圖形用戶界面實(shí)現(xiàn)與PC機(jī)聯(lián)機(jī)的數(shù)據(jù)采集器，同時(shí)借助系統(tǒng)的SD卡存儲(chǔ)獨(dú)立實(shí)現(xiàn)現(xiàn)場長時(shí)間采集數(shù)據(jù)。該數(shù)據(jù)采集器成本低，結(jié)構(gòu)簡單，體積小，已成功用于工業(yè)現(xiàn)場。
Abstract:
Aiming at the need of low cost data acquisition, a data acquisition device is designed based on C8051F340 which is a mixed-signal microcontroller and integrates USB controller and A/D controller on a chip.The data acquisition device which can combine with PC by USB interface and LabVIEW graphical user interface,can realize data acquisition. At the same time,it can be solely run a long time in virtue of SD card in field.The date aequisition device features low cost,simple structure and little sharp, and it has been used in industry field.
在需要實(shí)時(shí)大量輸入漢字的顯示控制處理應(yīng)用中，利用傳統(tǒng)單片機(jī)實(shí)現(xiàn)顯示控制的設(shè)計(jì)方法是較難實(shí)現(xiàn)的。帶漢字字庫的液晶模塊的使用使得小容量ROM單片機(jī)的大量漢字信息輸入與顯示成為可能。提出了針對漢字字庫編碼的二級(jí)索引拼音輸入檢索方法,介紹了以ST7920作為控制器的帶漢字字庫的液晶顯示模塊的接口方法及漢字顯示和控制原理，給出了通用計(jì)算機(jī)鍵盤在單片機(jī)中的串行接口，采用該技術(shù)可大大增強(qiáng)單片機(jī)的漢字輸入功能。為小容量ROM單片機(jī)的大批量漢字信息處理提供了一種漢字輸入解決方案。
Abstract:
It is difficult to realize Chinese characters input method based on the embedded system by using the traditional design method of display control. It is possible to input and display Chinese characters based on the embedded system with the ROM of small content by using the LCD module with Chinese characters.Chinese characters input method of the quadric index recall in allusion to Chinese characters code is brought forward.The interface and the principle of Chinese characters display control based on the LCD module controlled with the ST7920 is introduced too.The serial interface of the computer keyboard in common use and the embedded system is given at the same time. It can enhance the embedded system function of Chinese characters input by using this technology, and provide a kind of Chinese characters input scheme for the embedded system with small capacity ROM.
