Designers spend much time combating thermal effects incircuitry. The close relationship between temperature andelectronic devices is the source of more design headachesthan any other consideration.
標(biāo)簽： 測(cè)量 控制電路 管理技術(shù)
上傳時(shí)間： 2013-10-17
上傳用戶：風(fēng)之驕子
Occasionally, we are tasked with designing circuitry for aspecific purpose. The request may have customer originsor it may be an in-house requirement. Alternately, a circuitmay be developed because its possibility is simply tooattractive to ignore1. Over time, these circuits accumulate,encompassing a wide and useful body of proven capabilities.They also represent substantial effort. These considerationsmake publication an almost obligatory propositionand, as such, a group of circuits is presented here. This isnot the first time we have displayed such wares and, giventhe encouraging reader response, it will not be the last2.Eighteen circuits are included in this latest effort, roughlyarranged in the categories given in this publication’s title.They appear at the next paragraph.
標(biāo)簽： 信號(hào)源 調(diào)節(jié)器 電源 電路分析
上傳時(shí)間： 2013-11-12
上傳用戶：012345
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.
上傳時(shí)間： 2013-10-19
上傳用戶：royzhangsz
為了改變目前電網(wǎng)現(xiàn)場(chǎng)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(chǎng)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(chǎng)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(lái)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(lái)源。經(jīng)過(guò)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.
標(biāo)簽： 電網(wǎng) 信息化 管理系統(tǒng)
上傳時(shí)間： 2013-11-15
上傳用戶：han_zh
Demonstration circuit 1562A is an engineering toolto design and evaluate the LTC699X-X family ofTimerBlox circuits. The center section of the boardcontains a pre-configured TimerBlox function.DC1562A comes in twelve timing function variationsas outlined in Table 1.Surrounding the center board is a ”playground”prototyping area. The prototyping area has padsfor Dip-8, S8, MS8, or S6 packages with breadboarding connections to each pin and two convenientpower buses and ground bus surrounding theentire area. This area is for conditioning signals tocontrol the timer function and for adding loads controlled in time.
標(biāo)簽： 6994 LTC PCB 參考設(shè)計(jì)
上傳時(shí)間： 2013-10-18
上傳用戶：如果你也聽(tīng)說(shuō)
HIGH SPEED 8051 μC CORE - Pipe-lined Instruction Architecture; Executes 70% of Instructions in 1 or 2 System Clocks - Up to 25MIPS Throughput with 25MHz System Clock - 22 Vectored Interrupt Sources MEMORY - 4352 Bytes Internal Data RAM (256 + 4k) - 64k Bytes In-System Programmable FLASH Program Memory - External Parallel Data Memory Interface – up to 5Mbytes/sec DIGITAL PERIPHERALS - 64 Port I/O; All are 5V tolerant - Hardware SMBusTM (I2CTM Compatible), SPITM, and Two UART Serial Ports Available Concurrently - Programmable 16-bit Counter/Timer Array with 5 Capture/Compare Modules - 5 General Purpose 16-bit Counter/Timers - Dedicated Watch-Dog Timer; Bi-directional Reset CLOCK SOURCES - Internal Programmable Oscillator: 2-to-16MHz - External Oscillator: Crystal, RC, C, or Clock - Real-Time Clock Mode using Timer 3 or PCA SUPPLY VOLTAGE ........................ 2.7V to 3.6V - Typical Operating Current: 10mA @ 25MHz - Multiple Power Saving Sleep and Shutdown Modes 100-Pin TQFP (64-Pin Version Available) Temperature Range: –40°C to +85°C
標(biāo)簽： C8051F020
上傳時(shí)間： 2013-10-12
上傳用戶：lalalal
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.
標(biāo)簽： SerDes MAXX 9257 9258
上傳時(shí)間： 2014-01-24
上傳用戶：xingisme
針對(duì)科研實(shí)驗(yàn)中對(duì)拉壓千斤頂加載過(guò)程控制的需要，采用ATmega128單片機(jī)控制步進(jìn)電機(jī)進(jìn)而實(shí)現(xiàn)對(duì)執(zhí)行系統(tǒng)的電動(dòng)泵站實(shí)行自動(dòng)控制。對(duì)力和位移的數(shù)據(jù)采集與處理及用步進(jìn)電機(jī)控制電動(dòng)泵站手柄的技術(shù)細(xì)節(jié)作了重點(diǎn)描述。通過(guò)單片機(jī)的A/D變換器對(duì)AMP放大模塊采集的電橋信號(hào)作量化處理，千斤頂?shù)牟倏厥直恢靡离妱?dòng)油泵閥門開(kāi)啟的方向和大小作若干定位，單片機(jī)根據(jù)力或位移傳感器信號(hào)，實(shí)時(shí)控制步進(jìn)電機(jī)驅(qū)動(dòng)手柄旋轉(zhuǎn)到相應(yīng)操控位置。 Abstract: This article describes the use of ATmega128 AVR microcontroller series of DBS electric pumping stations and QF100/200 separate twoway hydraulic jack to automate the process of manipulating the work of the technical content. Articles on force and displacement data acquisition and processing， and stepper motor control electric pump with the handle of the key technical details were described. Through the MCU’s A / D converter module is collected on the AMP amplification quantify the signal bridge， jack handle position control valve opening according to the direction of electric pumps for a number of positioning and size of the microcontroller based on force or displacement sensor signals， real-time control stepper motor drive control handle rotate to the appropriate location.
標(biāo)簽： AVR 單片機(jī) 閉環(huán)控制
上傳時(shí)間： 2014-01-16
上傳用戶：hasan2015
針對(duì)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。基于W78E052D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(guò)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(kāi)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(jiǎn)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.
標(biāo)簽： 單片機(jī) B超 數(shù)字化 鍵盤設(shè)計(jì)
上傳時(shí)間： 2013-10-10
上傳用戶：asdfasdfd
為了有效地提升鉛酸蓄電池的使用壽命，同時(shí)實(shí)現(xiàn)對(duì)充電過(guò)程的監(jiān)控，設(shè)計(jì)出一種用單片機(jī)控制的36 V鉛酸蓄電池充電電源。本電路采用反激式拓?fù)洌B續(xù)電流工作模式，電源管理IC設(shè)計(jì)在電源的副邊，由ELAN公司的EM78P258N單片機(jī)模擬，是用可編程器件模擬電源管理IC，實(shí)現(xiàn)智能電源低成本化的一次成功嘗試，通過(guò)對(duì)單片機(jī)的軟件設(shè)計(jì)實(shí)現(xiàn)了充電電源的狀態(tài)顯示、充電時(shí)間控制、報(bào)警、過(guò)溫保護(hù)、過(guò)壓保護(hù)、過(guò)流保護(hù)等功能。本充電器真正的實(shí)現(xiàn)了鉛酸蓄電池的三段式充電過(guò)程，其最高輸出功率可達(dá)90 W，效率約85%，成本不到20元，具有很高的市場(chǎng)競(jìng)爭(zhēng)力。 Abstract: In order to extend the life of lead-acid battery efficiently and supervise the charging process meanwhile， a 36V lead-acid battery charge powe supply controlled by microcontroller is designed. The charger is flyback switching power supply and works in CCM mode. A EM78P258N microcontroller made by ELAN microelectronics corporation is used as power management IC which is designed at the secondary circuit. The project is a successful attempt to low-cost intelligent power used microcontroller simulating power management IC. The charger also has the functions of the status reveal， charge time control， alarming， thermal protect， current limit and overvoltage protect by the software design. The circuit actually implements the three-step charge process， whose power is up to 90W and whose efficiency can get 85%. The net cost of this charger is less than 20 RMB， so that the charger is of powerful market competitiveness.
標(biāo)簽： 單片機(jī)控制 充電電源 鉛酸蓄電池
上傳時(shí)間： 2013-11-16
上傳用戶：cepsypeng
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