介紹一種基于CAN總線的牽引變電站自動(dòng)化系統(tǒng)通訊規(guī)約的設(shè)計(jì)，CAN通訊規(guī)約采用標(biāo)準(zhǔn)幀，報(bào)文采用主動(dòng)發(fā)送和發(fā)送查詢兩種處理形式。該設(shè)計(jì)在城市輕軌與地鐵牽引變電站中的應(yīng)用表明：可實(shí)現(xiàn)間隔層和通訊處理層的數(shù)據(jù)快速、可靠的交換，提高牽引變電站的安全性和穩(wěn)定性 。 Abstract: This paper firstly presents a kind of design dealing with communicational protocol to the traction substation automation system based on CAN bus,and then comes up with the ideas that all frames of CAN communicational protocol should adopt the standard frame,and that messages be processed by two ways:sending initiatively and sending quiries.Subway and light rail application shows that the use of the CAN bus is possible to exchange data quickly and reliably between the layers of the middle and the communicational processing,hence to improve the safety and stability of traction substations.
上傳時(shí)間： 2013-11-07
上傳用戶：bs2005
該系統(tǒng)由單片機(jī)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(cè)量模塊等構(gòu)成，采用等精度測(cè)頻法測(cè)出頻率和周期，可測(cè)量有效值為0.01～5V，頻率范圍1Hz～20MHz信號(hào)的頻率、周期信號(hào)，精度高達(dá)10-6。采用計(jì)數(shù)法測(cè)量相位差，該系統(tǒng)可測(cè)量有效值0.5～5V，頻率10Hz～100kHz信號(hào)的相位差，精度為1°。系統(tǒng)功能由按鍵控制，測(cè)量結(jié)果實(shí)時(shí)顯示，人機(jī)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(jī) 多功能 計(jì)數(shù)器
上傳時(shí)間： 2013-11-04
上傳用戶：CHINA526
介紹一種多功能音樂(lè)播放器，它是以AT89S52單片機(jī)為核心，并輔有一些外圍器件，采用匯編語(yǔ)言編寫程序，實(shí)現(xiàn)多功能音樂(lè)播放，歌曲自動(dòng)循環(huán)播放和使用琴鍵自編曲目功能。此外，彩燈顯示歌曲節(jié)奏，按鍵跳轉(zhuǎn)到喜愛(ài)曲目，液晶顯示當(dāng)前播英文曲目。并給出了系統(tǒng)軟硬件設(shè)計(jì)。 Abstract: It introduces a multifunctional music player,taking AT89S52 single-chip microcomputer as hardware control core and using some peripheral elements.Programmes are compiled in assembly language to act as expected.There are two functional modes in this system.One is to make the music play automatically and consecutively,the other is to compose new songs through keys.In addition,lights show the pace of music and the English names can be displayed in the liquid crystal screen.With perfect combination of hardware and software,the music player can meet many music lovers’needs for multifunctional music player.And the hardware and software of the system are given.
上傳時(shí)間： 2013-11-18
上傳用戶：xiaodu1124
對(duì)于傳統(tǒng)的跑步機(jī)無(wú)法聯(lián)機(jī)組網(wǎng)，保存歷史數(shù)據(jù)，實(shí)時(shí)調(diào)試等問(wèn)題，介紹了一個(gè)由多臺(tái)跑步機(jī)通過(guò)RS-232串行總線與上位機(jī)相連組成的跑步機(jī)聯(lián)網(wǎng)系統(tǒng)。系統(tǒng)采用W77E58作為下位機(jī)核心控制器件，它具有雙串行通訊端口，其中一個(gè)串口用于與變頻器通訊，另一個(gè)串口則與上位機(jī)相連，構(gòu)成跑步機(jī)網(wǎng)絡(luò)。 Abstract: The traditional running machine can not be connected to a network, saving historical data, real time debug etc.In this paper,a new network system which is composed of running machines connected by a RS-232 communication bus is introduced.In the system,W77E58 is used as a core control unit.W77E58 has two serial ports,one is connected to the inverter and the other is connected to the PC. Thus a network appears.
標(biāo)簽： W77E58 跑步機(jī) 聯(lián)網(wǎng)系統(tǒng)
上傳時(shí)間： 2014-12-27
上傳用戶：哇哇哇哇哇
為深入了解基于UC3854A控制的PFC變換器中的動(dòng)力學(xué)特性，研究系統(tǒng)參數(shù)變化對(duì)變換器中分岔現(xiàn)象的影響，在建立Boost PFC變換器雙閉環(huán)數(shù)學(xué)模型的基礎(chǔ)上，用Matlab軟件對(duì)變換器中慢時(shí)標(biāo)分岔及混沌等不穩(wěn)定現(xiàn)象進(jìn)行了仿真。在對(duì)PFC變換器中慢時(shí)標(biāo)分岔現(xiàn)象仿真的基礎(chǔ)上，分析了系統(tǒng)參數(shù)變化對(duì)分岔點(diǎn)的影響，并進(jìn)行了仿真驗(yàn)證。仿真結(jié)果清晰地顯示了輸入整流電壓的幅值變化對(duì)系統(tǒng)分岔點(diǎn)的影響。 Abstract: In order to better understand the dynamics characteristic of power factor correction converter based on UC3854A， and make the way that parameters change influences the bifurcation phenomena of the system clearly. The math model of the two closed loop circuits to the Boost PFC （Power Factor Correction） converter controller was built. Then， with the help of Matlab， the simulation for nonlinear phenomena such as chaos and slow-scale bifurcation in the PFC converter was made. Finally the factors that have influence to the phenomenon of bifurcation under slow-scale in PFC converter were analyzed. The simulation results clearly show the parameters change influences the bifurcation point of the system.
上傳時(shí)間： 2013-10-17
上傳用戶：杜瑩12345
基于幅移鍵控技術(shù)ASK（Amplitude-Shift Keying），以C8051F340單片機(jī)作為監(jiān)測(cè)終端控制器，C8051F330D單片機(jī)作為探測(cè)節(jié)點(diǎn)控制器，采用半雙工的通信方式，通過(guò)監(jiān)控終端和探測(cè)節(jié)點(diǎn)的無(wú)線收發(fā)電路，實(shí)現(xiàn)數(shù)據(jù)的雙向無(wú)線傳輸。收發(fā)電路采用直徑為0.8 mm的漆包線自行繞制成圓形空心線圈天線，天線直徑為（3.4±0.3）cm。試驗(yàn)表明，探測(cè)節(jié)點(diǎn)與監(jiān)測(cè)終端的通信距離為24 cm，通過(guò)橋接方式，節(jié)點(diǎn)收發(fā)功率為102 mW時(shí)，節(jié)點(diǎn)間的通信距離可達(dá)20 cm。與傳統(tǒng)無(wú)線收發(fā)模塊相比，該無(wú)線收發(fā)電路在受體積、功耗、成本限制的場(chǎng)合有廣闊的應(yīng)用前景。 Abstract: Based on ASK technology and with the C8051F340 and C8051F330D MCU as the controller， using half-duplex communication mode， this paper achieves bi-directional data transfer. Transceiver circuit constituted by enameled wire which diameter is 0.8mm and wound into a diameter （3.4±0.3） cm circular hollow coil antenna. Tests show that the communication distance between detection and monitoring of the terminal is 24cm，the distance is up to 20cm between two nodes when using the manner of bridging and the node transceiver power is 102mW. Compared with the conventional wireless transceiver modules， the circuit has wide application prospect in small size， low cost and low power consumption and other characteristics.
標(biāo)簽： C8051F 單片機(jī) 無(wú)線收發(fā) 電路設(shè)計(jì)
上傳時(shí)間： 2013-10-19
上傳用戶：xz85592677
The PCF8578 is a low power CMOS1 LCD row and column driver, designed to drive dotmatrix graphic displays at multiplex rates of 1:8, 1:16, 1:24 or 1:32. The device has40 outputs, of which 24 are programmable and configurable for the following ratios ofrows/columns: 32¤8, 24¤16, 16¤24 or 8¤32. The PCF8578 can function as a stand-alone LCDcontroller and driver for use in small systems. For larger systems it can be used inconjunction with up to 32 PCF8579s for which it has been optimized. Together these twodevices form a general purpose LCD dot matrix driver chip set, capable of driving displaysof up to 40960 dots. The PCF8578 is compatible with most microcontrollers andcommunicates via a two-line bidirectional bus (I2C-bus). Communication overhead isminimized by a display RAM with auto-incremented addressing and display bankswitching.
標(biāo)簽： 8578 PCF LCD 圖形點(diǎn)陣
上傳時(shí)間： 2013-10-23
上傳用戶：頂?shù)弥?/p>
NXP Semiconductor designed the LPC2400 microcontrollers around a 16-bit/32-bitARM7TDMI-S CPU core with real-time debug interfaces that include both JTAG andembedded Trace. The LPC2400 microcontrollers have 512 kB of on-chip high-speedFlash memory. This Flash memory includes a special 128-bit wide memory interface andaccelerator architecture that enables the CPU to execute sequential instructions fromFlash memory at the maximum 72 MHz system clock rate. This feature is available onlyon the LPC2000 ARM Microcontroller family of products. The LPC2400 can execute both32-bit ARM and 16-bit Thumb instructions. Support for the two Instruction Sets meansEngineers can choose to optimize their application for either performance or code size atthe sub-routine level. When the core executes instructions in Thumb state it can reducecode size by more than 30 % with only a small loss in performance while executinginstructions in ARM state maximizes core performance.
上傳時(shí)間： 2013-11-15
上傳用戶：zouxinwang
The PCA9674/74A provide general purpose remote I/O expansion for most microcontroller families via the two-line bidirectional bus (I2C-bus) and is a part of the Fast-mode Plus (Fm+) family.
上傳時(shí)間： 2013-10-28
上傳用戶：linyao
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(shí)間： 2013-10-27
上傳用戶：黑漆漆
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