為了解決磁放大器性能測試過程中，需要對其供給不同數(shù)值恒定電流的問題，設(shè)計(jì)了一種基于DAC7512和單片機(jī)的數(shù)控恒流源系統(tǒng)。該系統(tǒng)采用AT89C51作為主控器件，將計(jì)算機(jī)發(fā)送的電流控制字命令轉(zhuǎn)換為D/A轉(zhuǎn)換器控制字，通過模擬SPI通信接口，寫D/A控制字到DAC7512，從而控制其輸出相應(yīng)數(shù)字電壓值，經(jīng)差動縮放電路、電壓/電路變換電路和功率驅(qū)動電路，最后輸出恒定電流。實(shí)驗(yàn)結(jié)果表明，恒流源輸出電流調(diào)節(jié)范圍為-45~+45 mA、精度為±0.1 mA，分辨率達(dá)0.024 4 mA，具有應(yīng)用靈活，外圍電路簡單，可靠性高的特點(diǎn)。該數(shù)控直流恒流源也可為相關(guān)產(chǎn)品的測試系統(tǒng)研發(fā)提供參考。 Abstract: In order to solve the need to supply different values constant current for the magnetic amplifier in testing process， numerical control constant current source system was designed based on DAC7512 chip and microcontroller technology. The system used the AT89C51 as the main chip， which can convert the current control word from computer into to D/A control words. And the system wrote D/A control word into the DAC7512 chip to control the output voltage value by the SPI communication interface， which can output corresponding constant current figures by scaling circuit， the V/I converter and power drive circuit. Experimental results show that the current source output current adjustment range is -45~+45mA， accuracy is ± 0.1mA， and resolution ratio is 0.024 4mA
標(biāo)簽： 7512 DAC 數(shù)控直流 恒流源
上傳時(shí)間： 2014-12-27
上傳用戶：invtnewer
提出了一種基于C8051F320的列車安全巡檢儀的設(shè)計(jì)方案，詳細(xì)闡述了巡檢儀的各個模塊的硬、軟件設(shè)計(jì)。巡檢儀集信息采集、軸溫檢測、照明和記錄存儲等功能于一體，實(shí)現(xiàn)了對列車安全巡檢工作有效的監(jiān)督和科學(xué)管理。系統(tǒng)軟件采用C51編寫，對單片機(jī)進(jìn)行有效的電源管理，保證了巡檢儀的穩(wěn)定性、可靠性和低功耗性。 Abstract: This paper puts forward a design of train safety inspection based on C8051F320,describes all modules hardware and software design of inspection instrument.The inspection instrument has the function of information collection, axle’s temperature detection, lighting and records storage.It can supervise and administer train safety inspection work effectively.The system software using C51 can manage the power of single chip microcomputer, and guarantee the stability, reliability and low power consumption of the inspection instrument.
標(biāo)簽： C8051F320 列車 儀的設(shè)計(jì) 巡檢
上傳時(shí)間： 2013-12-22
上傳用戶：落花無痕
基于CC1110單片機(jī)公交報(bào)站系統(tǒng)主要由CC1110單片機(jī)最小系統(tǒng)和WT588D語音模塊組成，提出了如何實(shí)現(xiàn)語音報(bào)站，通過無線通信SimpliciTI網(wǎng)絡(luò)協(xié)議實(shí)現(xiàn)公交站臺的自動播報(bào)和OLCD液晶顯示公交運(yùn)行的各類信息。結(jié)果表明，該公交報(bào)站系統(tǒng)報(bào)站準(zhǔn)確率99%，價(jià)格比同類產(chǎn)品下降了300%以上，系統(tǒng)組成結(jié)構(gòu)簡單，提高了系統(tǒng)的抗干擾性和穩(wěn)定性，也便于攜帶。 Abstract: The bus stop announcement system based on CC1110 MCU is composed of CC1110 MCU minimum system and WT588D voice module. How to achieve the voice announcing is put forward.The bus-stop will announce automatically and display on the OLCD by means of wireless communication SimpliciTI network protocol. As a result， the bus station stop announcement systems reported 99% accuracy rate， price of similar products declined by 300% or more， system of simple structure， improve the anti-jamming and stability of the power system， it is also portable.
標(biāo)簽： 1110 CC 單片機(jī) 公交報(bào)站
上傳時(shí)間： 2013-10-21
上傳用戶：baby25825
通過對程控濾波器的理論分析，在研究MAX262的功能和單片機(jī)的SPI總線通信的基礎(chǔ)上，提出了基于MAX262的程控濾波器設(shè)計(jì)方案，設(shè)計(jì)了程控濾波器的軟硬件，并給出了測試結(jié)果。 Abstract: By analyzing the programmable filter,the paper puts forward a programmable filter system design based on MAS262 on basic of studying MAS262 features and SPI bus communication.Software and hardware of the programmmable filter are designed,and the test result is given.
標(biāo)簽： MAX 262 程控 濾波器設(shè)計(jì)
上傳時(shí)間： 2013-11-15
上傳用戶：wxhwjf
為深入了解基于UC3854A控制的PFC變換器中的動力學(xué)特性，研究系統(tǒng)參數(shù)變化對變換器中分岔現(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
以AVR單片機(jī)ATmega8和USB接口器件PDIUSBD12為核心，基于標(biāo)準(zhǔn)的USB1.1協(xié)議，設(shè)計(jì)一種通用USB接口模塊，以滿足嵌入式系統(tǒng)中對USB接口的需求。對模塊的硬件電路或單片機(jī)固件程序的硬件接口層稍加修改即可用于其他各種微處理器。該模塊可為各種嵌入式系統(tǒng)增加USB接口,實(shí)現(xiàn)與USB主機(jī)系統(tǒng)通信。 Abstract: Based on AVR microcontroller ATmega8 and USB interface chip PDIUSBD12, a general USB interface module is designed according to USB1.1 protocol for various requirements of embedded systems. Only with few modifications in circuit or hardware abstract layer of firmware, the module can be used on many types of microprocessors. All kinds of embedded systems can realize high speed and stable communication with USB host systems, owing to the facility of this module.
標(biāo)簽： AVR USB 單片機(jī) 接口設(shè)計(jì)
上傳時(shí)間： 2014-01-08
上傳用戶：趙云興
針對材料試驗(yàn)機(jī)等設(shè)備中要求測量或控制材料拉伸或壓縮的位移，一般采用光電軸角編碼器檢測位置信號，輸出正交編碼脈沖信號。若采用其他方法檢測位置信號，必然導(dǎo)致電路設(shè)計(jì)復(fù)雜，可靠性降低。因此，提出一種基于LS7266R1的電子式萬能材料試驗(yàn)機(jī)設(shè)計(jì)方案。給出了試驗(yàn)機(jī)中的控制器工作原理，LS7266R1與單片機(jī)的接口硬件設(shè)計(jì)，以及主程序軟件流程圖。巧妙地把力量傳感器，位移傳感器等機(jī)械運(yùn)動狀態(tài)的壓力或拉力以及位置坐標(biāo)，變成了電壓信號和電脈沖數(shù)字信號，供A/D測量和LS7266R1計(jì)數(shù)，從而實(shí)現(xiàn)了獨(dú)立完成材料試驗(yàn)控制或通過PC機(jī)串口命令完成材料試驗(yàn)控制。 Abstract: Aiming at the requirement that the displacement of the tension and compression always be tested and controlled in the equipement such as material testing machine. The position signal was tested by photoelectric axial angle coder. Therefore， the paper proposes the design of electronic universal testing machine design based on LS7266R1. If the position signal detected by other methods， will inevitably lead to the circuit design complexity， reliability decreased. The work theory of the controller， the hardware interface design between LS7266R1 and single chip， and the flow chart of main program， are presented in this paper. The signal of the compression or tension power and displacement at working， which tested by power sensor and displacement sensor especially， is changed into electric voltage and electric pulse numerical signals. And these signals can be tested by A/D and counted by LS7266R1. Finally the test of the material properties can be controlled by itself， or controlled by the COM command of PC.
上傳時(shí)間： 2013-11-02
上傳用戶：yl1140vista
介紹一種應(yīng)用于長城賽弗SUV汽車后門車窗多功能控制器，能實(shí)現(xiàn)對電動玻璃車窗、車窗雨刮器、噴水器以及電加熱除霜器等控制。介紹了基于NXP P89LPC922單片機(jī)多功能汽車后車窗控制器的控制功能、硬件電路原理和軟件設(shè)計(jì)方法。 Abstract: This paper presents a multipurpose automotive rear windows controller for CHANGCHENG SAFE SUV.The controller can control rear power-operated window,rear wiping,washing water pump and rear defroster of the windows. In this paper, it is introduced in detail that the functions and the design of the circuit and program of the controller based on NXP P89LPC922 MCU.
上傳時(shí)間： 2013-11-13
上傳用戶：z754970244
介紹了MPC555與CS8900A擴(kuò)展以太網(wǎng)的硬件設(shè)計(jì)圖。以NUCLUES PLUS操作系統(tǒng)為基礎(chǔ)，介紹了網(wǎng)卡軟件驅(qū)動程序的編制，給出了以太網(wǎng)協(xié)議包嵌入NUCLEUS PLUS操作系統(tǒng)的實(shí)現(xiàn)方法。 Abstract: The Ethernet extension hardware design of MPC555 and CS8900A are introduced,and the software driven program based on NUCLEUS PLUS operation system and the technique that Ethernet protocol embedded in NUCLEUS PLUS real operation system are discussed.
上傳時(shí)間： 2013-10-23
上傳用戶：xiehao13
主要介紹了以PIC18F2480單片機(jī)為處理器，基于可編程多路開關(guān)檢測接口器件MC33993實(shí)現(xiàn)的車用多路開關(guān)檢測接口電路的設(shè)計(jì)。該設(shè)計(jì)克服了以往基于分立元件的檢測接口電路的弊端，簡化了接口電路設(shè)計(jì)，保證了車用開關(guān)工作的可靠性和安全性。 Abstract: The design of automotive multiple switch detection interface circuit based on MC33993 is introduced mainly which adopts PIC18F2480 single chip microprocessor.This circuit overcomes shortage of traditional design which contains many schism elements, and the application of MC33993 also predigests the whole design of interface circuit and guarantees the dependability and security of the switch.
標(biāo)簽： 33993 MC 多路開關(guān) 檢測
上傳時(shí)間： 2013-11-19
上傳用戶：star_in_rain
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