Once relegated to the hinterlands of low cost indicatorlights, the LED is again in the spotlight of the lightingworld. LED lighting is now ubiquitous, from car headlightsto USB-powered lava lamps. Car headlights exemplifyapplications that capitalize on the LED’s clear advantages—unwavering high quality light output, tough-assteelrobustness, inherent high effi ciency—while a USBlava lamp exemplifi es applications where only LEDs work.Despite these clear advantages, their Requirement forregulated voltage and current make LED driver circuitsmore complex than the venerable light bulb, but some newdevices are closing the gap. For instance, the LTM®8040μModule™ LED driver integrates all the driver circuitryinto a single package, allowing designers to refocus theirtime and effort on the details of lighting design criticalto a product’s success.
A frequent Requirement in systems involves drivinganalog signals into non-linear or reactive loads. Cables,transformers, actuators, motors and sample-hold circuitsare examples where the ability to drive diffi cult loads isrequired. Although several power buffer amplifi ers areavailable, none have been optimized for driving diffi cultloads.
Occasionally, we are tasked with designing circuitry for aspecific purpose. The request may have customer originsor it may be an in-house Requirement. Alternately, a circuitmay be developed because its possibility is simply tooattractive to ignore1. Over time, these circuits accumulate,encompassing a wide and useful body of proven capabilities.They also represent substantial effort. These considerationsmake publication an almost obligatory propositionand, as such, a group of circuits is presented here. This isnot the first time we have displayed such wares and, giventhe encouraging reader response, it will not be the last2.Eighteen circuits are included in this latest effort, roughlyarranged in the categories given in this publication’s title.They appear at the next paragraph.
Sensing and/or controlling current flow is a fundamental Requirement in many electronics systems, and the tech-niques to do so are as diverse as the applications them-selves. This Application Note compiles solutions to cur-rent sensing problems and organizes the solutions by general application type. These circuits have been culled from a variety of Linear Technology documents
便攜式信號(hào)采集在機(jī)器健康診斷系統(tǒng)中有較高的應(yīng)用價(jià)值。機(jī)器健康診斷的信號(hào)特點(diǎn)是包括低頻信號(hào)。本文研究是為了實(shí)現(xiàn)簡易而且低成本的低頻便攜式信號(hào)采集。以Microchip公司單片機(jī)PIC18F1320為核心設(shè)計(jì)信號(hào)采集電路，實(shí)現(xiàn)了信號(hào)的采集和保存。系統(tǒng)采用串行電可擦除芯片24LC32A保存數(shù)據(jù)，經(jīng)過有線通信，信號(hào)數(shù)據(jù)由串行口通過MAX232芯片輸送到微型計(jì)算機(jī)接收和保存，最后繪制出信號(hào)波形。 微型計(jì)算機(jī)程序采用Visual Basic編程。研究成功采樣頻率為3 kHz的復(fù)雜信號(hào)，證明該方案符合設(shè)計(jì)要求。
Abstract:
Portable signal acquisition is useful in machine health monitoring systems. The signal characteristics of machine health monitoring includes low frequency signals. The goal of this study is to realize simple, inexpensive and portable low frequency signal sampling. This paper provides the project of signal acquisition system design based on PIC18F1320 microcontroller manufactured by the Microchip Technology Incorporation to achieve signal sampling and storage. The system adopted EEPROM 24LC32A to store the signal data. The microcomputer received data via wired link with the MAX232 IC through the serial port. The microcomputer program, programmed in Visual Basic, received the data, stored it and plotted the signal. The study successfully samples 3kHz complicated signals and thus meets the design Requirement.
針對(duì)材料試驗(yàn)機(jī)等設(shè)備中要求測(cè)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(cè)位置信號(hào)，輸出正交編碼脈沖信號(hào)。若采用其他方法檢測(cè)位置信號(hào)，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(dòng)狀態(tài)的壓力或拉力以及位置坐標(biāo)，變成了電壓信號(hào)和電脈沖數(shù)字信號(hào)，供A/D測(cè)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.
基于PIC單片機(jī)的脈沖電源:設(shè)計(jì)了一種金屬凝固過程用脈沖電源。該電源采用PIC16F877作為主控芯片，實(shí)現(xiàn)對(duì)窄脈沖電流幅值的檢測(cè)，以及時(shí)電流脈沖幅值根據(jù)模糊PID算法進(jìn)行閑環(huán)控制。使用結(jié)果表明：該電源的輸出脈沖波形良好，電流幅值穩(wěn)定，滿足合金材料凝固過程的工藝要求且運(yùn)行穩(wěn)定可靠。關(guān)鍵詞：脈沖電源；PIC16F877單片機(jī)；模糊PID；閑環(huán)控制
Abstract：A kind of pulse power supply was designed which uses in the metal solidification process ．．I11is power supply used PIC16F877 to take the master control chip reali on to the narrow pulse electric current peak-to-peak value examination，carried on the closed-loop control to the electric current pulse peak-to-peak value basis fuzzy PID algorithm．The use result indicated ，this power supply output se profile is good，and the electric current peak-to-p~k value is stable，It satisfies the alloy material solidification process the technological Requirement and movement stable reliable，Key words：p se po wer supply；PIC16F877single-chip microcontroller；f r PID；closed-loop control
為了在CDMA系統(tǒng)中更好地應(yīng)用QDPSK數(shù)字調(diào)制方式，在分析四相相對(duì)移相（QDPSK)信號(hào)調(diào)制解調(diào)原理的基礎(chǔ)上，設(shè)計(jì)了一種QDPSK調(diào)制解調(diào)電路，它包括串并轉(zhuǎn)換、差分編碼、四相載波產(chǎn)生和選相、相干解調(diào)、差分譯碼和并串轉(zhuǎn)換電路。在MAX+PLUSⅡ軟件平臺(tái)上，進(jìn)行了編譯和波形仿真。綜合后下載到復(fù)雜可編程邏輯器件EPM7128SLC84-15中，測(cè)試結(jié)果表明，調(diào)制電路能正確選相，解調(diào)電路輸出數(shù)據(jù)與QDPSK調(diào)制輸入數(shù)據(jù)完全一致，達(dá)到了預(yù)期的設(shè)計(jì)要求。
Abstract:
In order to realize the better application of digital modulation mode QDPSK in the CDMA system， a sort of QDPSK modulation-demodulation circuit was designed based on the analysis of QDPSK signal modulation-demodulation principles. It included serial/parallel conversion circuit, differential encoding circuit, four-phase carrier wave produced and phase chosen circuit, coherent demodulation circuit, difference decoding circuit and parallel/serial conversion circuit. And it was compiled and simulated on the MAX+PLUSⅡ software platform,and downloaded into the CPLD of EPM7128SLC84-15.The test result shows that the modulation circuit can exactly choose the phase，and the output data of the demodulator circuit is the same as the input data of the QDPSK modulate. The circuit achieves the prospective Requirement of the design.
針對(duì)飛行模擬器座艙數(shù)據(jù)采集的復(fù)雜性，設(shè)計(jì)了一種基于以太網(wǎng)分布式的數(shù)據(jù)采集控制系統(tǒng)，該系統(tǒng)是RCM5700微處理器模塊上的以太網(wǎng)應(yīng)用。在系統(tǒng)的基礎(chǔ)上具體討論了PoE技術(shù)的應(yīng)用，在傳輸數(shù)據(jù)的網(wǎng)線上同時(shí)提供電流，提出并實(shí)現(xiàn)了一種包括輔助電源在內(nèi)的完整可靠的PoE供電方案。設(shè)計(jì)采用美國國家半導(dǎo)體的LM5073和LM5576并根據(jù)不同的負(fù)載情況，進(jìn)行穩(wěn)定可靠的電壓轉(zhuǎn)換，以滿足數(shù)據(jù)采集電路的要求。實(shí)驗(yàn)結(jié)果表明：該設(shè)計(jì)穩(wěn)定可靠，滿足低于13 W的采集節(jié)點(diǎn)供電要求，提高了模擬器信號(hào)采集系統(tǒng)的通用性和標(biāo)準(zhǔn)化程度，避免了以往數(shù)據(jù)采集節(jié)點(diǎn)單獨(dú)繁瑣的電源設(shè)計(jì)。
Abstract:
Aiming at the complexity of large avion simulation and controlling，the simulator cabin distribute data collecting and control system was designed. This system is the application of RCM5700 on Ethernet. Based on this system，PoE technique that makes Ethernet can also provide power were expounded with emphasis and included FAUX design the PoE resolution was realized. To achieve the Requirement of this system，LM5073 and LM5576 were used to DC-DC switch. From the data of experiment，the design filled the Requirement of power-need of node whose power was lower than 13W. The application of the technique can advance the degree of simulation data collections currency and standardization and avoid designing additional power system.
為了能夠滿足基站易于選址、優(yōu)質(zhì)快速的建站要求和易維護(hù)、低成本、高可靠的運(yùn)行要求，本文對(duì)以方艙來實(shí)現(xiàn)一體化結(jié)構(gòu)基站做出一番探討。從系統(tǒng)設(shè)計(jì)的觀點(diǎn)闡述了移動(dòng)通信高性能基站天線設(shè)計(jì)的幾個(gè)關(guān)鍵問題，介紹了智能天線技術(shù)在基站中的應(yīng)用，并且用HFSS軟件仿真了一種新型的對(duì)稱陣子天線，該天線駐波比小于2的帶寬可以達(dá)到60%，具有良好的寬頻帶特性。
Abstract:
In order to meet the station construction Requirement of easy site selection and fast base station， and meet the operational Requirement of easy maintenance， low cost and high reliability， this paper discussed the unified architecture base station using shelter. Several key problems of high performance mobile communication base station antenna were illustrated from the view of system design， the application of smart antenna in base station was also introduced. And a novel dipole antenna was simulated by using HFSS， the VSWR of the antenna is less than 2， and the bandwidth was reach to 60%. So it has good broadband properties.
