學會不畫電路圖，不用網(wǎng)絡表，用手工布線。從而加深對PCB電路版圖設計的理解。
標簽： PCB
上傳時間： 2013-10-10
上傳用戶：wang5829
隨著傳統(tǒng)能源成本不斷增長，可替代能源持續(xù)受到青睞，如今它已不僅僅是減少環(huán)境污染的一種手段。可再生能源系統(tǒng)的新研發(fā)成果使之成為商業(yè)上可行的替代技術。當前最常用的可替代能源包括小型水輪機、風力發(fā)電機組和太陽能光伏發(fā)電。20年來，太陽能電能的使用量以每年20-25%的增幅穩(wěn)定增長；近五年來，每年的增長速度將近50％。2001年，太陽能系統(tǒng)的裝機容量還不到350 MW。而到2005年，太陽能光伏發(fā)電系統(tǒng)的發(fā)電量已達到1.460 GW。這一數(shù)字在2006年已增加到1.744 GW。并網(wǎng)系統(tǒng)的安裝量已近兩倍于離網(wǎng)型系統(tǒng)，導致這種現(xiàn)象的原因有兩個：第一，大多數(shù)家庭和商業(yè)機構都使用公用電網(wǎng)。第二，大多數(shù)政府激勵計劃只面向并網(wǎng)系統(tǒng)。大部分并網(wǎng)應用都是“分布式”的，即系統(tǒng)安裝在使用端。
標簽： 并網(wǎng)逆變器 控制
上傳時間： 2013-10-29
上傳用戶：hanhanhan
淘寶買的模塊說明書，有代碼，供參考
上傳時間： 2013-11-18
上傳用戶：wch1989
無
上傳時間： 2013-10-10
上傳用戶：448949
瑞薩電子基于RX62T單片機的PMSM電機位置控制英文資料：RX62T基于RX CPU架構，集成了增強的定時器單元（MTU3、GPT）、12位AD轉換器（1μs轉換時間），每個AD轉換單元還集成可調增益運放和窗口比較器，適用于各種電機控制和變頻器應用。最近瑞薩電子推出先進電機控制算法，其關鍵技術包括高級脈沖幅值調制技術、先進的電動機驅動技術等。基于RX62T高性能32位CISC MCU，使用瑞薩先進電機控制算法實現(xiàn)空調壓縮機控制時，可以實現(xiàn)如下系統(tǒng)規(guī)格：適用空調器制冷量范圍《8000W，低頻振動最高振幅《300μm，壓縮機轉速范圍為1～150rps，功率因數(shù)額定工況》0.9，滿載高達100%，調制度《200%，電流檢測方式為單電阻檢測。它不但可以提供業(yè)界最精簡的BOM，還可以在不增加BOM成本的情況下實現(xiàn)更多的功能。
上傳時間： 2013-10-20
上傳用戶：ve3344
本設計基于MSP430F161x/261x + CC2420/2520實驗板，給出了物聯(lián)網(wǎng)感知層的一些基本操作，包括傳感器數(shù)據(jù)獲取和低功耗無線數(shù)據(jù)通信兩個方面。特別是對MSP430和CC2420/2520的配合給出了較為詳細的說明及例程。由華東師范大學TI MSP430聯(lián)合實驗室提供。
上傳時間： 2013-11-06
上傳用戶：qw12
模擬串口就是利用51的兩個輸入輸出引腳如P1.0和P1.1,置1或0分別代表高低電平,也就是串口通信中所說的位,如起始位用低電平,則將其置0,停止位為高電平,則將其置1,各種數(shù)據(jù)位和校驗位則根據(jù)情況置1或置0。至于串口通信的波特率,說到底只是每位電平持續(xù)的時間,波特率越高,持續(xù)的時間越短。如波特率為9600BPS,即每一位傳送時間為1000ms/9600=0.104ms,即位與位之間的延時為為0.104毫秒。單片機的延時是通過執(zhí)行若干條指令來達到目的的,因為每條指令為1-3個指令周期,可即是通過若干個指令周期來進行延時的,單片機常用11.0592M的的晶振,現(xiàn)在我要告訴你這個奇怪數(shù)字的來歷。用此頻率則每個指令周期的時間為(12/11.0592)us,那么波特率為9600BPS每位要間融多少個指令周期呢？
上傳時間： 2013-10-29
上傳用戶：zw380105939
特點： • 8/10 位精度 • 7 us, 10-位單次轉換時間. • 采樣緩沖放大器 • 可編程采樣時間 • 左/右 對齊, 有符號/無符號結果數(shù)據(jù) • 外部觸發(fā)控制 • 轉換完成中斷 • 模擬輸入8通道復用 • 模擬/數(shù)字輸入引腳復用 • 1到8轉換序列長度 • 連續(xù)轉換模式 • 多通道掃描方式
上傳時間： 2014-12-28
上傳用戶：88mao
All inputs of the C16x family have Schmitt-Trigger input characteristics. These Schmitt-Triggers are intended to always provide proper internal low and high levels, even if anundefined voltage level (between TTL-VIL and TTL-VIH) is externally applied to the pin.The hysteresis of these inputs, however, is very small, and can not be properly used in anapplication to suppress signal noise, and to shape slow rising/falling input transitions.Thus, it must be taken care that rising/falling input signals pass the undefined area of theTTL-specification between VIL and VIH with a sufficient rise/fall time, as generally usualand specified for TTL components (e.g. 74LS series: gates 1V/us, clock inputs 20V/us).The effect of the implemented Schmitt-Trigger is that even if the input signal remains inthe undefined area, well defined low/high levels are generated internally. Note that allinput signals are evaluated at specific sample points (depending on the input and theperipheral function connected to it), at that signal transitions are detected if twoconsecutive samples show different levels. Thus, only the current level of an input signalat these sample points is relevant, that means, the necessary rise/fall times of the inputsignal is only dependant on the sample rate, that is the distance in time between twoconsecutive evaluation time points. If an input signal, for instance, is sampled throughsoftware every 10us, it is irrelevant, which input level would be seen between thesamples. Thus, it would be allowable for the signal to take 10us to pass through theundefined area. Due to the sample rate of 10us, it is assured that only one sample canoccur while the signal is within the undefined area, and no incorrect transition will bedetected. For inputs which are connected to a peripheral function, e.g. capture inputs, thesample rate is determined by the clock cycle of the peripheral unit. In the case of theCAPCOM unit this means a sample rate of 400ns @ 20MHz CPU clock. This requiresinput signals to pass through the undefined area within these 400ns in order to avoidmultiple capture events.For input signals, which do not provide the required rise/fall times, external circuitry mustbe used to shape the signal transitions.In the attached diagram, the effect of the sample rate is shown. The numbers 1 to 5 in thediagram represent possible sample points. Waveform a) shows the result if the inputsignal transition time through the undefined TTL-level area is less than the time distancebetween the sample points (sampling at 1, 2, 3, and 4). Waveform b) can be the result ifthe sampling is performed more than once within the undefined area (sampling at 1, 2, 5,3, and 4).Sample points:1. Evaluation of the signal clearly results in a low level2. Either a low or a high level can be sampled here. If low is sampled, no transition willbe detected. If the sample results in a high level, a transition is detected, and anappropriate action (e.g. capture) might take place.3. Evaluation here clearly results in a high level. If the previous sample 2) had alreadydetected a high, there is no change. If the previous sample 2) showed a low, atransition from low to high is detected now.
上傳時間： 2013-10-23
上傳用戶：copu
All inputs of the C16x family have Schmitt-Trigger input characteristics. These Schmitt-Triggers are intended to always provide proper internal low and high levels, even if anundefined voltage level (between TTL-VIL and TTL-VIH) is externally applied to the pin.The hysteresis of these inputs, however, is very small, and can not be properly used in anapplication to suppress signal noise, and to shape slow rising/falling input transitions.Thus, it must be taken care that rising/falling input signals pass the undefined area of theTTL-specification between VIL and VIH with a sufficient rise/fall time, as generally usualand specified for TTL components (e.g. 74LS series: gates 1V/us, clock inputs 20V/us).The effect of the implemented Schmitt-Trigger is that even if the input signal remains inthe undefined area, well defined low/high levels are generated internally. Note that allinput signals are evaluated at specific sample points (depending on the input and theperipheral function connected to it), at that signal transitions are detected if twoconsecutive samples show different levels. Thus, only the current level of an input signalat these sample points is relevant, that means, the necessary rise/fall times of the inputsignal is only dependant on the sample rate, that is the distance in time between twoconsecutive evaluation time points. If an input signal, for instance, is sampled throughsoftware every 10us, it is irrelevant, which input level would be seen between thesamples. Thus, it would be allowable for the signal to take 10us to pass through theundefined area. Due to the sample rate of 10us, it is assured that only one sample canoccur while the signal is within the undefined area, and no incorrect transition will bedetected. For inputs which are connected to a peripheral function, e.g. capture inputs, thesample rate is determined by the clock cycle of the peripheral unit. In the case of theCAPCOM unit this means a sample rate of 400ns @ 20MHz CPU clock. This requiresinput signals to pass through the undefined area within these 400ns in order to avoidmultiple capture events.
上傳時間： 2014-04-02
上傳用戶：han_zh
