波长信号的解调是实现光纤光栅传感网络的关键，基于现有的光纤光栅传感器解调方法，提出一种基于FPGA的双匹配光纤光栅解调方法，此系统是一种高速率、高精度、低成本的解调系统，并且通过引入双匹配光栅有效地克服了双值问题同时扩大了检测范围。分析了光纤光栅的测温原理并给出了该方案软硬件设计，综合考虑系统的解调精度和FPGA的处理速度给出了基于拉格朗日的曲线拟合算法。 Abstract: Sensor is one of the most important application of the fiber grating. Wavelength signal demodulating is the key techniques to carry out fiber grating sensing network， based on several existing methods of fiber grating sensor demodulation inadequate， a two-match fiber grating demodulation method was presented. This system is a high-speed， high precision， low-cost demodulation system. And by introducing a two-match grating effectively overcomes the problem of double value while expands the scope of testing. This paper analyzes the principle of fiber Bragg grating Temperature and gives the software and hardware design of the program. Considering the system of demodulation accuracy and processing speed of FPGA，this paper gives the curve fitting algorithm based on Lagrange.
上传时间： 2013-10-10
上传用户：zxc23456789
Integrated EMI/Thermal Design forSwitching Power SuppliesWei ZhangThesis submitted to the Faculty of theVirginia Polytechnic Institute and State Universityin partial fulfillment of the requirements for the degree of Integrated EMI/Thermal Design forSwitching Power SuppliesWei Zhang(ABSTRACT)This work presents the modeling and analysis of EMI and thermal performancefor switch power supply by using the CAD tools. The methodology and design guidelinesare developed.By using a boost PFC circuit as an example, an equivalent circuit model is builtfor EMI noise prediction and analysis. The parasitic elements of circuit layout andcomponents are extracted analytically or by using CAD tools. Based on the model, circuitlayout and magnetic component design are modified to minimize circuit EMI. EMI filtercan be designed at an early stage without prototype implementation.In the second part, thermal analyses are conducted for the circuit by using thesoftware Flotherm, which includes the mechanism of conduction, convection andradiation. Thermal models are built for the components. Thermal performance of thecircuit and the Temperature profile of components are predicted. Improved thermalmanagement and winding arrangement are investigated to reduce Temperature.In the third part, several circuit layouts and inductor design examples are checkedfrom both the EMI and thermal point of view. Insightful information is obtained.
上传时间： 2013-11-16
上传用户：萍水相逢
Abstract: Many modern industrial, medical, and commercial applications require Temperature measurements in the extended Temperature rangewith accuracies of ±0.3°C or better, performed with reasonable cost and often with low power consumption. This article explains how platinumresistance Temperature detectors (PRTDs) can perform measurements over wide Temperature ranges of -200°C to +850°C, with absolute accuracyand repeatability better than ±0.3°C, when used with modern processors capable of resolving nonlinear mathematical equation quickly and costeffectively. This article is the second installment of a series on PRTDs. For the first installment, please read application note 4875, "High-Accuracy Temperature Measurements Call for Platinum Resistance Temperature Detectors (PRTDs) and Precision Delta-Sigma ADCs."
上传时间： 2013-11-06
上传用户：WMC_geophy
Logger iButton devices have gained a lot of popularity with researchers. Although free evaluation software is easy to use and welldocumented, the choices and inputs that need to be made can sometimes be challenging. This application note explains technicalterms that are common with Temperature logger iButtons and how they relate to each other. Additionally, it presents an algorithm tohelp users choose the necessary input parameters, including the sample rate based on a user's needs and the available memory tostore the data.
上传时间： 2013-11-16
上传用户：xywhw1
Frequently, voltage reference stability and noise defi nemeasurement limits in instrumentation systems. In particular,reference noise often sets stable resolution limits.Reference voltages have decreased with the continuingdrop in system power supply voltages, making referencenoise increasingly important. The compressed signalprocessing range mandates a commensurate reductionin reference noise to maintain resolution. Noise ultimatelytranslates into quantization uncertainty in A to D converters,introducing jitter in applications such as scales, inertialnavigation systems, infrared thermography, DVMs andmedical imaging apparatus. A new low voltage reference,the LTC6655, has only 0.3ppm (775nV) noise at 2.5VOUT.Figure 1 lists salient specifi cations in tabular form. Accuracyand Temperature coeffi cient are characteristic ofhigh grade, low voltage references. 0.1Hz to 10Hz noise,particularly noteworthy, is unequalled by any low voltageelectronic reference.
上传时间： 2013-10-30
上传用户：wxhwjf
nRF24E1编程下载板是我们自行开发的简易无线通信模块nRF24E1的在线下载板，使用方便。 nRF24E1编程下载板源程序包括上位机程序、单片机固件程序和nRF24E1内51核控制程序， 分别存放在“上位机程序”、“AT89S52”和“nRF24E1”三个文件夹内。 “上位机程序”内有应用软件download.exe。 “AT89S52”内有单片机固件源程序download.c，可以直接编译连接生成下载文件，下载到目标单片机AT89S52中。 “nRF24E1”内有控制nRF24E1工作的源程序，分别是： 24E1.c:典型控制应用； putchar.c:nRF24E1串行通信源程序； transmit.c:nRF24E1无线发送源程序； receive.c:nRF24E1无线接收源程序； “Temperature”：nRF24E1控制DS18B20温度采集并无线发送源程序。
上传时间： 2015-05-07
上传用户：songyue1991
Digital Thermostat with High Accuracy -6,00 to 46,00 °C Digital Thermostat We build a digital thermostat for home applications, which controls the room Temperature. I used the AT90S2313 microprocessor of ATMEL. The digital thermostat opens the main heating valve of the apartment and the hot water flows in the radiators. Digital Thermostat Board
标签： Thermostat Digital Accuracy digital
上传时间： 2014-01-18
上传用户：D&L37
This program demonstrates operation of ADC0 in polled mode. The ADC0 is // configured to use writes to AD0BUSY as its start of conversion source and // to measure the output of the on-chip Temperature sensor. The Temperature // sensor output is converted to degrees Celsius and is transmitted out UART0
标签： ADC0 demonstrates configured operation
上传时间： 2014-01-23
上传用户：wangyi39
This program demonstrates operation of ADC0 in polled mode. The ADC0 is // configured to use writes to AD0BUSY as its start of conversion source and // to measure the output of the on-chip Temperature sensor. The Temperature // sensor output is converted to degrees Celsius and is transmitted out UART0
标签： ADC0 demonstrates configured operation
上传时间： 2014-08-18
上传用户：米卡
nRF24E1编程下载板是我们自行开发的简易无线通信模块nRF24E1的在线下载板，使用方便。 nRF24E1编程下载板源程序包括上位机程序、单片机固件程序和nRF24E1内51核控制程序， 分别存放在“上位机程序”、“AT89S52”和“nRF24E1”三个文件夹内。 “上位机程序”内有应用软件download.exe。 “AT89S52”内有单片机固件源程序download.c，可以直接编译连接生成下载文件，下载到目标单片机AT89S52中。 “nRF24E1”内有控制nRF24E1工作的源程序，分别是： 24E1.c:典型控制应用； putchar.c:nRF24E1串行通信源程序； transmit.c:nRF24E1无线发送源程序； receive.c:nRF24E1无线接收源程序； “Temperature”：nRF24E1控制DS18B20温度采集并无线发送源程序。
上传时间： 2013-12-02
上传用户：jackgao
