Abstract: A resistive feedback network is often used to set the output voltage of a power supply. A mechanical potentiometer (pot)conveniently solves the problem of adjusting a power supply. For easier automatic calibration, a mechanical pot can be replaced witha digital pot. This application note presents a calibration solution that uses a digital pot, because digipots are smaller, do not movewith age or vibration, and can be recalibrated remotely. This proposed solution reduces the susceptibility of the system to thetolerance of the digital pot's end-to-end resistance, making the solution optimal fordesigners. This application note also explainssome of the equations required to calculate the resistor chain values and to use a digital pot in this way. A spreadsheet withstandard reisistor values is available for easy calculations.
上傳時間： 2013-10-31
上傳用戶：caiguoqing
PCI ExpressTM is the third generation of PCI (PeripheralComponent Interconnect) technology used to connect I/Operhipheral devices in computer systems. It is intended asa general purpose I/O device interconnect that meets theneeds of a wide variety of computing platforms such asdesktop, mobile, server and communications. It alsospecifies the electrical and mechanical attributes of thebackplane, connectors and removable cards in thesesystems.
上傳時間： 2013-11-17
上傳用戶：squershop
Abstract: As electronic systems take over many of the mechanical functions in a car—ranging from engine timing to steering andbraking—there is a growing concern about fault tolerance. There should not be a single point of failure that would prevent a car fromat least "limping" off the road or making it to the nearest service station. Redundant systems, watchdog timers, and other controlcircuits are used to reroute signals and perform other functions that ensure that a vehicle can safely make it off the road when afailure occurs.
上傳時間： 2013-11-10
上傳用戶：diets
為了提高PCB板制作的效率，改變傳統的化學腐蝕制板工藝，使用機械仿形銑制作電路板的方法，設計了以ATMEGA16單片機為核心部件的PCB板雕刻機控制系統。其中包括PCB雕刻機的基本功能、主要硬件電路設計和軟件的實現流程，并給出了相關設計電路。重點分析了雕刻機步進電機的驅動電路以及主軸電機的驅動電路，該雕刻機經實際運行，系統工作良好，可有效提高PCB板的制作效率。 Abstract: In order to improve the efficiency of production of PCB board and change the traditional chemical etching plates， using of mechanical copying milling method makes circuit boards，this paper introduces the PCB engraving machine control system used ATMEGA16 microcomputer as the core components. It includes basic function， the hardware circuit design and software realization process， and gives the corresponding circuit design.It analyses the drive circuit of engrawing machine stepper motor and spindle motor in detail. This engraving machine by practical operation， the system works well， which can effectively improve the production efficiency of PCB board.
上傳時間： 2013-10-17
上傳用戶：liangliang123
針對目前使用的RS232接口數字化B超鍵盤存在PC主機啟動時不能設置BIOS，提出一種PS2鍵盤的設計方法。基于W78E052D單片機，采用8通道串行A/D轉換器設計了8個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送，正交編碼器信號通過XC9536XL轉換為單片機可接收的中斷信號，軟件接收到中斷信息后等效處理成按鍵。結果表明，在滿足開機可設置BIOS同時，又可實現超聲特有功能，不需要專門設計驅動程序，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.
上傳時間： 2013-10-10
上傳用戶：asdfasdfd
針對當前安檢力學試驗機所能完成的試驗種類單一、自動化程度低等問題，提出一種以ATmega128單片機為核心控制器的安檢力學試驗機的設計。詳細闡述了該安檢力學試驗機各個組成部分的設計原理和方案，并且給出了各部分的軟件設計思想和操作流程。經過大量測試試驗表明：設計的安檢力學試驗機可以完成多達十余種的力學安檢試驗，完全符合相關國家標準，并且具有數據采集精度高、傳輸速度快、操作安全簡便等特點，實現了安檢設備的多功能化、數字化和自動化。 Abstract: Currently， many mechanical security testing machines have only one function. The degree of automation of them is low. To solve those problems， a new kind of mechanical security testing machine， using ATmega128 micro-controller as its core controller， has been advanced. It describes the components of the machine. The principles and the scheme in the designing processes are presented in detail， and the software architecture and the operation processes of each part are given. After having done many testing， we have reached the following conclusions: the mechanical security testing machine presented can do over ten mechanical security tests complying with related national standards. It has high data acquisition accuracy and high transmission speed. The operation of the machine is simple and safe. In general， this machine is a multi-functional， highly automatic， digitalized security testing device.
上傳時間： 2013-11-05
上傳用戶：a67818601
Information in this document is subject to change without notice and does notrepresent a commitment on the part of the manufacturer. The software describedin this document is furnished under license agreement or nondisclosureagreement and may be used or copied only in accordance with the terms of theagreement. It is against the law to copy the software on any medium except asspecifically allowed in the license or nondisclosure agreement. The purchasermay make one copy of the software for backup purposes. No part of this manualmay be reproduced or transmitted in any form or by any means, electronic ormechanical, including photocopying, recording, or information storage andretrieval systems, for any purpose other than for the purchaser’s personal use,without written permission.
上傳時間： 2014-12-27
上傳用戶：Tracey
CAT5110/18/19/23/24/25 linear-taper digitally programmable potentiometers perform the same function as a mechanical potentiometer or a variable resistor. These devices consist of a fixed resistor and a wiper contact with 32-tap points that are digitally controlled through a2-wire up/down serial interface.
上傳時間： 2013-11-22
上傳用戶：541657925
Xilinx is disclosing this user guide, manual, release note, and/or specification (the "Documentation") to you solely for use in the developmentof designs to operate with Xilinx hardware devices. You may not reproduce, distribute, republish, download, display, post, or transmit theDocumentation in any form or by any means including, but not limited to, electronic, mechanical, photocopying, recording, or otherwise,without the prior written consent of Xilinx. Xilinx expressly disclaims any liability arising out of your use of the Documentation. Xilinx reservesthe right, at its sole discretion, to change the Documentation without notice at any time. Xilinx assumes no obligation to correct any errorscontained in the Documentation, or to advise you of any corrections or updates. Xilinx expressly disclaims any liability in connection withtechnical support or assistance that may be provided to you in connection with the Information.
上傳時間： 2014-01-13
上傳用戶：竺羽翎2222
Xilinx is disclosing this user guide, manual, release note, and/or specification (the “Documentation”) to you solely for use in the development of designs to operate with Xilinx hardware devices. You may not reproduce, distribute, republish, download, display, post, or transmit the Documentation in any form or by any means including, but not limited to, electronic, mechanical, photocopying, recording, or otherwise, without the prior written consent of Xilinx. Xilinx expressly disclaims any liability arising out of your use of the Documentation. Xilinx reserves the right, at its sole discretion, to change the Documentation without notice at any time. Xilinx assumes no obligation to correct any errors contained in the Documentation, or to advise you of any corrections or updates. Xilinx expressly disclaims any liability in connection with technical support or assistance that may be provided to you in connection with the Information.
標簽： CPLD
上傳時間： 2013-10-22
上傳用戶：李哈哈哈
