特別好的教程特別好的教程 RESEARCH progress in synthesis and modification of polylactic acid RESEARCH progress in synthesis and modification of polylactic acid
標(biāo)簽： 教程
上傳時(shí)間： 2021-09-17
上傳用戶：陳浩
RESEARCH on microwave power amplififiers has gained a growing importance demanded by the many continuously developing applications which require such subsystem performance. A broad set of commercial and strategic systems in fact have their overall performance boosted by the power amplififier, the latter becoming an enabling component wherever its effificiency and output power actually allows functionalities and operating modes previously not possible. This is the case for the many wireless systems and battery-operated systems that form the substrate of everyday life, but also of high-performance satellite and dual-use systems.
標(biāo)簽： 高效率 射頻 微波 固態(tài) 功率放大器
上傳時(shí)間： 2021-10-30
上傳用戶：得之我幸78
Position-sensitive gaseous photomultipliers RESEARCH and applications by Francke, Tom Peskov, Vladimir (z-lib.org)-email.pdf
標(biāo)簽： 光電倍增管
上傳時(shí)間： 2022-01-16
上傳用戶：aben
溫度控制如今已成為當(dāng)代社會(huì)研究的熱點(diǎn)之一,而溫度檢測(cè)在現(xiàn)代設(shè)備參數(shù)檢測(cè)中也是一項(xiàng)極其重要的技術(shù),應(yīng)用十分廣泛。與傳統(tǒng)的測(cè)溫方法相比,紅外測(cè)溫方法具有時(shí)間短、精度高、使用簡(jiǎn)單方便等優(yōu)點(diǎn)。本文以環(huán)境溫度為被測(cè)對(duì)象,設(shè)計(jì)了以STC89C52單片機(jī)為控制中心的紅外測(cè)溫裝置,能夠?qū)崿F(xiàn)對(duì)目標(biāo)溫度的實(shí)時(shí)采集、處理、顯示和報(bào)警等功能。本設(shè)計(jì)主要是由STC89C52單片機(jī)、紅外測(cè)溫傳感器、LCD1602液晶顯示器、按鍵和蜂鳴器等部分組成,采用非接觸的方式對(duì)目標(biāo)溫度進(jìn)行實(shí)時(shí)檢測(cè)。Temperature control has become one of the hotspots in contemporary social RESEARCH,and temperature detection is an extremely important technology in modern equipment parameter detection.Compared with traditional method,the infrared temperature measuring method has advantages of short time,high precision and convenient operation,etc.This paper consider environment temperature as RESEARCH objects and designs an infrared temperature measuring device which employs the STC89C52singlechipas-control center,and it can realize timely collection,processing,display and alarm function of the target temperature.The design is mainly composed of STC89C52 singlechip,infrared temperature sensor,LCD1602monitor,keys and buzzer,etc.This design detects the target temperature by non-contact method.
上傳時(shí)間： 2022-03-27
上傳用戶：jiabin
數(shù)字示波器功能強(qiáng)大,使用方便,但是價(jià)格相對(duì)昂貴。本文以Ti的MSP430F5529為主控器,以Altera公司的EP2C5T144C8 FPGA器件為邏輯控制部件設(shè)計(jì)數(shù)字示波器。模擬信號(hào)經(jīng)程控放大、整形電路后形成方波信號(hào)送至FPGA測(cè)頻,根據(jù)頻率值選擇采用片上及片外高速AD分段采樣。FPGA控制片外AD采樣并將數(shù)據(jù)輸入到FIFO模塊中緩存,由單片機(jī)進(jìn)行頻譜分析。測(cè)試表明:簡(jiǎn)易示波器可以實(shí)現(xiàn)自動(dòng)選檔、多采樣率采樣、高精度測(cè)頻及頻譜分析等功能。Digital oscilloscope is powerful and easy to use, but also expensive. The RESEARCH group designed a low-cost digital oscilloscope, the chip of MSP430F5529 of TI is chosen as the main controller and the device of EP2C5T144C8 of Altera company is used as the logic control unit. Analog signal enter the programmable amplifier circuit, shaping circuit and other pre-processing circuit. The shaped rectangular wave signal is sent to FPGA for measure the frequency. According to the frequency value to select AD on-chip or off-chip high-speed AD for sampling. FPGA controls the off-chip AD sampling and buffers AD data by FIFO module. The single chip microcomputer receives the data, and do FFT for spectrum analysis. The test shows that the simple oscilloscope can realize automatic gain selection, sampling at different sampling rates, high precision frequency measurement and spectrum analysis.
標(biāo)簽： msp430 單片機(jī) fpga 數(shù)字示波器
上傳時(shí)間： 2022-03-27
上傳用戶：
設(shè)計(jì)功率MOSFET驅(qū)動(dòng)電路時(shí)需重點(diǎn)考慮寄生參數(shù)對(duì)電路的影響。米勒電容作為MOSFET器件的一項(xiàng)重要參數(shù),在驅(qū)動(dòng)電路的設(shè)計(jì)時(shí)需要重點(diǎn)關(guān)注。重點(diǎn)觀察了MOSFET的開(kāi)通和關(guān)斷過(guò)程中柵極電壓、漏源極電壓和漏源極電流的變化過(guò)程,并分析了米勒電容、寄生電感等寄生參數(shù)對(duì)漏源極電壓和漏源極電流的影響。分析了柵極電壓在米勒平臺(tái)附近產(chǎn)生振蕩的原因,并提出了抑制措施,對(duì)功率MOSFET的驅(qū)動(dòng)設(shè)計(jì)具有一定的指導(dǎo)意義。When designing the drive circuit of power MOSFET,the influence of parasitic parameters on the circuit should be concerned.As an important parameter of MOSFET device,Miller capacitance should be considered in the design of drive circuit.The variation of gate voltage,drain source voltage and drain source current during the turn-on and turn-off of MOSFET were observed.The influences of parasitic parameters such as Miller capacitance and parasitic inductance on drain source voltage and drain source current were analyzed.The reasons of gate voltage oscillation nearby Miller plateau were analyzed,and the restraining measures were put forward.This RESEARCH was instructive for the drive design of power MOSFET.
標(biāo)簽： mosfet
上傳時(shí)間： 2022-04-02
上傳用戶：默默
在全球氣候變暖和石油資源短缺的形勢(shì)下,推動(dòng)新能源汽車的發(fā)展將成為汽車行業(yè)一種新的發(fā)展方向。在大力發(fā)展新能源電動(dòng)汽車行業(yè)的同時(shí)還應(yīng)兼顧電動(dòng)汽車充電設(shè)施的發(fā)展,因此對(duì)電動(dòng)汽車充電樁的設(shè)計(jì)與研究顯得十分必要。對(duì)電動(dòng)汽車直流充電樁的硬件系統(tǒng)進(jìn)行設(shè)計(jì),主要的硬件電路包括安全監(jiān)測(cè)電路、總壓采集電路、溫濕度檢測(cè)電路、語(yǔ)音電路。軟件包括主要流程圖和溫濕度檢測(cè)流程圖。Under the situation of global warming and shortage of petroleum resources,promoting the development of new energy vehicles will become a new development direction for the automotive industry.While vigorously developing the new energy electric vehicle industry,we should also take into account the development of electric vehicle charging facilities.Therefore,the design and RESEARCH of electric vehicle charging piles is very necessary.The hardware system of the electric vehicle DC charging pile is designed.The main hardware circuits include safety monitoring circuit,total voltage collecting circuit,temperature and humidity detecting circuit,voice circuit and CAN communication.The software includes a main flow chart and a temperature and humidity detection flow chart.
標(biāo)簽： 電動(dòng)汽車
上傳時(shí)間： 2022-04-03
上傳用戶：jason_vip1
本文首次設(shè)計(jì)并驗(yàn)證了基于macom三合一芯片設(shè)計(jì)的光模塊電路,該電路旨在提供一種滿足SFF-8472中規(guī)定的數(shù)字診斷功能的低成本SFP+模塊。電路采用激光器驅(qū)動(dòng)、限幅放大器、控制器以及時(shí)鐘恢復(fù)單元集成的單芯片,在保證高精度數(shù)字診斷功能基礎(chǔ)上,實(shí)現(xiàn)了低成本高可靠的特點(diǎn)。該電路在光接收接口組件與激光器驅(qū)動(dòng)和限幅放大器單元的限幅放大器部分之間接入濾波器來(lái)提高模塊的靈敏度及信號(hào)質(zhì)量。在控制器單元的數(shù)字電位器的引腳上采用外加電阻的方式避免出現(xiàn)上電不發(fā)光的故障問(wèn)題。該研究結(jié)果為下一代SFP-DD光模塊設(shè)計(jì)與開(kāi)發(fā)工作,奠定了一定的理論與實(shí)踐基礎(chǔ)。This paper designs and validates the optical module circuit based on the MACOM Trinity chip for the first time.This circuit aims to provide a low-cost SFP module which meets the digital diagnosis function specified in SFF-8472.The circuit uses a single chip integrated with laser driver,limiting amplifier,controller and clock recovery unit.On the basis of ensuring high precision digital diagnosis function,it achieves the characteristics of low cost and high reliability.The circuit connects a filter between the optical receiving interface module and the limiting amplifier part of the laser driver and limiting amplifier unit to improve the sensitivity and signal quality of the module.The pin of the digital potentiometer in the controller unit is equipped with an external resistance to avoid the problem of power failure.The RESEARCH results lay a theoretical and practical foundation for optical module design in high-speed data center.
上傳時(shí)間： 2022-04-03
上傳用戶：
介紹一種萬(wàn)能模擬信號(hào)輸入采集電路,可以同時(shí)支持電壓、電流、熱電偶、熱電阻等常見(jiàn)的工業(yè)類型信號(hào),方便后級(jí)電路的測(cè)量。該研究成果通過(guò)不斷優(yōu)化和完善,已成功應(yīng)用到了中控儀表的新產(chǎn)品中。The paper introduces a collection circuit of universal signal input. The circuit support voltage, current, thermocouple, thermal resistance and other common industrial type signal. The RESEARCH results, which has been continuous optimized and improved, has been successfully applied to the new production of Zhejiang Supcon Instrument Co., Ltd.
標(biāo)簽： 采集電路
上傳時(shí)間： 2022-04-21
上傳用戶：slq1234567890
隨著科技的發(fā)展，人們?cè)谌粘Ｉ钪惺褂玫碾娖髟絹?lái)越多，電子設(shè)備的電磁兼容性（EMC）也越來(lái)越重要。所以，人們對(duì)電子設(shè)備的電磁兼容性的要求也越來(lái)越嚴(yán)格，越來(lái)越規(guī)范。而在市場(chǎng)競(jìng)爭(zhēng)中，如何降低成本、減少設(shè)備體積，是各電子設(shè)備制造廠家重點(diǎn)研究的課題。通過(guò)對(duì)開(kāi)關(guān)電源的EMI濾波電路的類別和相應(yīng)的技術(shù)特點(diǎn)進(jìn)行分析，設(shè)計(jì)出一種既能提高性能，又能降低成本的濾波電路。With the development of technology, appliances people use in their daily lives, more and more electronic devices electromagnetic compatibility （ EMC ） has become increasingly important. So, people electromagnetic compatibility requirements of electronic devices have become increasingly stringent, more and more standardized. The competition in the market, how to reduce costs, reduce equipment size, is the subject of the electronic equipment manufacturer focused on RESEARCH. Through the technical characteristics of the respective category and the EMI filter circuit switching power supply is analyzed both designed to improve a performance of the filter circuit can reduce the cost.
標(biāo)簽： 開(kāi)關(guān)電源 濾波電路
上傳時(shí)間： 2022-04-23
上傳用戶：
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