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該系統(tǒng)由單片機89S52控制模塊，程控寬帶放大模塊，整形模塊，F(xiàn)PGA內(nèi)頻率、相位差測量模塊等構(gòu)成，采用等精度測頻法測出頻率和周期，可測量有效值為0.01～5V，頻率范圍1Hz～20MHz信號的頻率、周期信號，精度高達10-6。采用計數(shù)法測量相位差，該系統(tǒng)可測量有效值0.5～5V，頻率10Hz～100kHz信號的相位差，精度為1°。系統(tǒng)功能由按鍵控制，測量結(jié)果實時顯示，人機界面友好。
Abstract:
The system consists of the following functional blocks:89S52microcontroller controlling module,programmable amplifier module,comparator module,frequency and phase difference testing module in the FPGA.The system use the equal accuracy frequency-examining technique it measures frequency and circle of signal which its ranges is from1Hz to20MHz and the amplitude of which its range is from0.01Vrms to5Vrms,precision is up to10-6.Using of count method,the system detects the phase difference of signal,the amplitude of whic its range is from0.5Vrms to5Vrms and the frequency of which its ranges is from10Hz to100kHz,precision is up to1°,The system functions is controlled by certain keys,measurement results are displayed in real-time and it is friendly interface.
標(biāo)簽：
89S52
單片機
多功能
計數(shù)器
上傳時間：
2013-11-04
上傳用戶：CHINA526
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以89S52單片機和EP1C6Q240C8型FPGA為控制核心的多功能計數(shù)器，是由峰值檢波、A/D轉(zhuǎn)換、程控放大、比較整形、移相網(wǎng)絡(luò)部分組成,可實現(xiàn)測量正弦信號的頻率、周期和相位差的功能。多功能計數(shù)器采用等精度的測量方法，可實現(xiàn)頻率為1Hz～10MHz、幅度為0.01～5Vrms的正弦信號的精確測頻，以及頻率為10Hz～100kHz、幅度為0.5～5Vrms的正弦信號精確測相。液晶顯示器能夠?qū)崟r顯示當(dāng)前信號的頻率、周期和相位差。該多功能計數(shù)器精度高，界面友好，實用性強。
Abstract:
A multi-function counter，which uses89S52MCU and EP1C6Q240C8FPGA as a control core，consists of peak detector，A/D conversion，program-controlled amplification，compared shaping and phase-shifting network part.The counter measures the frequency，period and phase of sinusoidal signal.With the equal precision method,the multi-function counter achieves the precise frequency measurement of the sinusoidal signal which its frequency is from1Hz to10MHz，its amplitude is from0.01Vrms to5Vrms，as well as the accurate phase measurement of the sinusoidal signal which its frequency is from10Hz to100kHz，its amplitude is from0.5Vrms to5Vrms.The LCD monitor real-time displays the frequency，period and phase difference of current signal.The multi-function counter features high precision，friendly interface，and strong practical.
標(biāo)簽：
FPGA
單片機
多功能
計數(shù)器
上傳時間：
2013-11-15
上傳用戶：gy592333
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This application report discusses the design of non-invasive optical plethysmographyalso called as pulsoximeter using the MSP430FG437 Microcontroller (MCU). Thepulsoximeter consists of a peripheral probe combined with the MCU displaying theoxygen saturation and pulse rate on a LCD glass. The same sensor is used for bothheart-rate detection and pulsoximetering in this application. The probe is placed on aperipheral point of the body such as a finger tip, ear lobe or the nose. The probeincludes two light emitting diodes (LEDs), one in the visible red spectrum (660nm) andthe other in the infrared spectrum (940nm). The percentage of oxygen in the body isworked by measuring the intensity from each frequency of light after it transmitsthrough the body and then calculating the ratio between these two intensities.
標(biāo)簽：
Pulsoximeter
Single-Chip
Des
上傳時間：
2013-10-27
上傳用戶：黑漆漆
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This document provides practical, common guidelines for incorporating PCI Express interconnect
layouts onto Printed Circuit Boards (PCB) ranging from 4-layer desktop baseboard designs to 10-
layer or more server baseboard designs. Guidelines and constraints in this document are intended
for use on both baseboard and add-in card PCB designs. This includes interconnects between PCI
Express devices located on the same baseboard (chip-to-chip routing) and interconnects between
a PCI Express device located “down” on the baseboard and a device located “up” on an add-in
card attached through a connector.
This document is intended to cover all major components of the physical interconnect including
design guidelines for the PCB traces, vias and AC coupling capacitors, as well as add-in card
edge-finger and connector considerations. The intent of the guidelines and examples is to help
ensure that good high-speed signal design practices are used and that the timing/jitter and
loss/attenuation budgets can also be met from end-to-end across the PCI Express interconnect.
However, while general physical guidelines and suggestions are given, they may not necessarily
guarantee adequate performance of the interconnect for all layouts and implementations.
Therefore, designers should consider modeling and simulation of the interconnect in order to
ensure compliance to all applicable specifications.
The document is composed of two main sections. The first section provides an overview of
general topology and interconnect guidelines. The second section concentrates on physical layout
constraints where bulleted items at the beginning of a topic highlight important constraints, while
the narrative that follows offers additional insight.
標(biāo)簽：
pci
PCB
設(shè)計規(guī)范
上傳時間：
2014-01-24
上傳用戶：s363994250
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代碼名稱： Snitz Forums 2000
代碼語言： 英文
代碼類型： 國外代碼
運行環(huán)境： ASP
授權(quán)方式： 免費代碼
代碼大小： 530kb
代碼等級： 3
整理時間： 2006-3-15 16:42:00
聯(lián) 系 人：
開 發(fā) 商：
演示地址：
簡 介： Snitz Forums 2000, one of the best ASP based bulletin board systems on the market. Getting better every day! A complete board system (forum) that allows the user access to a friendly and intuitive interface.
Snitz Forums 2000 v3.4.05 [74]
標(biāo)簽：
代碼
Forums
Snitz
2000
上傳時間：
2015-06-03
上傳用戶：caixiaoxu26
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Introducing a new product requires the designer to think about the product differentiators. Designing a user-friendly product, considering all other features are equivalent, will help increase the product acceptance and sales. A good User Interface is definitively one of these differentiators. In many instances, a Graphical User Interface (GUI) is the best approach.
標(biāo)簽：
product
differentiators
Introducing
the
上傳時間：
2015-07-04
上傳用戶：cx111111
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A Java package (library/API) to connect and use the Yahoo Instant Messager and Chat protocols (YMSG), in a reasonably coder-friendly and abstract way. Although methods the API exposes are closely matched to Yahoo IM features, the API attempts to hide
Download jYMSG API - Yahoo IM
Jars
標(biāo)簽：
and
protocols
Messager
Instant
上傳時間：
2015-09-14
上傳用戶：zhaiyanzhong
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In 1960, R.E. Kalman published his famous paper describing a recursive solution to the discretedata
linear filtering problem [Kalman60]. Since that time, due in large part to advances in digital
computing, the
Kalman filter
has been the subject of extensive research and application,
particularly in the area of autonomous or assisted navigation. A very “friendly” introduction to the
general idea of the Kalman filter can be found in Chapter 1 of [Maybeck79], while a more complete
introductory discussion can be found in [Sorenson70], which also contains some interesting
historical narrative.
標(biāo)簽：
R.E.
discretedata
describing
published
上傳時間：
2015-10-22
上傳用戶：a673761058
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Linux in a Nutshell, 5th Edition
By Stephen Figgins, Robert Love, Arnold Robbins, Ellen Siever, Aaron Weber
... ... ... ... ... ... ... .....
Publisher: O Reilly
Pub Date: July 2005
ISBN: 0-596-00930-5
Pages: 944
Over the last few years, Linux has grown both as an operating system and a tool for personal and business use. Simultaneously becoming more user friendly and more powerful as a back-end system, Linux has achieved new plateaus: the newer filesystems have solidified, new commands and tools have appeared and become standard, and the desktop--including new desktop environments--have proved to be viable, stable, and readily accessible to even those who don t consider themselves computer gurus.
標(biāo)簽：
Nutshell
Edition
Figgins
Stephen
上傳時間：
2015-12-03
上傳用戶：frank1234
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《JavaServer Faces》
In JavaServer Faces, developers learn how to use the new JavaServer Faces framework to build real-world web applications. The book contains everything you ll need: how to construct the HTML on the front end how to create the user interface components that connect the front end to your business objects how to write a back-end that s JSF-friendly and how to create the deployment descriptors that tie everything together. This book is a complete guide to the crucial new JSF technology.
標(biāo)簽：
JavaServer
Faces
developers
framew
上傳時間：
2016-01-02
上傳用戶：redmoons
