基于at89s51單片機(jī)觸發(fā)的直流升壓斬波電路研究-wenkub
2023-02-02 16:09:41 本頁面
【正文】 院（系、部） 電氣控制工程 專 業(yè) 班 級 電力101班 學(xué) 號 1005030104 姓 名 馮旭 日 期 2013年1月13日 摘 要 本設(shè)計基于AT89S51單片機(jī)為核心的PWM升壓斬波電路(Boost Chopper)。同時相對于單純依靠電路元件而形成的觸發(fā)脈沖進(jìn)行的PWM調(diào)制，基于AT89S51單片機(jī)的PWM發(fā)生裝置具有電路簡單，可調(diào)性高等特點(diǎn)。PWM控制方式是目前采用最廣泛的一種控制方式，它具有良好的調(diào)整特性。它是用柵極電壓來控制漏極電流的，因此它的一個顯著特點(diǎn)是驅(qū)動電路簡單，需要的驅(qū)動功率小；第二個顯著特點(diǎn)是開關(guān)速度快、工作頻率高。設(shè)V處于通態(tài)的時間為，此階段電感L上積蓄的能量為。電路中導(dǎo)通角與關(guān)斷角的關(guān)系如下所示 （13） 因此，式（12）可表示為 （14）升壓斬波電路之所以能使輸出電壓高于電源電壓，關(guān)鍵有兩個原因：一是電感L儲能之后具有使電壓泵升的作用，二是電容C的作用使得輸出電壓不變，但實(shí)際上C值不可能為無窮大，在此階段其向負(fù)載放電，必然會有所下降，故實(shí)際輸出電壓會略低于式（14）所得結(jié)果。為獲得精準(zhǔn)的觸發(fā)脈沖，通常選用AT89S51單片機(jī)做為脈沖發(fā)生器。其電路圖如圖32所示，采用高速光隔（6N137）輸出，并將PWM的信號倒相。注意，本最小應(yīng)用系統(tǒng)只能作為小型的數(shù)字量測控單元。其主程序流程如圖27所示。但是計算機(jī)仿真卻可以解決這個問題。它支持連續(xù)、離散、及兩者混合的線性和非線性系統(tǒng)。即滿足理論計算公式。 遇到的問題和困難： (1) 在計算元器件參數(shù)是缺少理論依據(jù)難以正確的計算相應(yīng)的參數(shù)。雖然遇到了許多的困難但是我還是通過不斷的學(xué)習(xí)解決了這些難題。 (4) 在面對學(xué)習(xí)上的困難時一定要堅(jiān)持不懈的努力才能打敗困難，獲得更多以的知識。 （2）負(fù)載不變?yōu)?00，頻率1KHz，占空比從5%到95%以等百分比遞增時，直流升壓斬波電路的負(fù)載輸出波形及輸出電壓大小。設(shè)計必須按期完成。 your employer dismisses you and you think that you have been dismissed unfairly.For more information about dismissal and unfair dismissal, seeagainst the disciplinary action your employer has taken against you. However, if you win your case, the tribunal may reduce any pensation awarded to you as a result of your failure to appeal.Remember that in most cases you must make an application to an employment tribunal within three months of the date when the event you are plaining about happened. If your application is received after this time limit, the tribunal will not usually accept it.If you are worried about how the time limits apply to you, take advice from one of the organisations listed undert charge you more than 35% of your pensation To find your nearest CAB, including those that give advice by , click ons 150th anniversary celebrations and will attend City39。for the racist behaviour of their fans durings actions.CSKA said they were surprised and disappointed by Toure39。總覺得自己自己似乎應(yīng)該去做點(diǎn)什么，或者寫點(diǎn)什么。t really grow up, it seems is not so important。Originally, this world, can produce a chemical reaction to an event, in addition to resolutely, have to do, and time. 原來，這個世界上，對某個事件能產(chǎn)生化學(xué)反應(yīng)的，除了非做不可的堅(jiān)決，還有，時間。也曾經(jīng)好像已經(jīng)下定了決心去做某件事，但更多的時候是最后又打起了退堂鼓。 Those were broken into various shapes of stationery。突然想到那件藍(lán)格子襯衫；那些被折成各種各樣形狀的信紙；那段從街角深巷伊始的友誼；還有那場還沒有開始就宣告了終結(jié)的邂逅計劃……那些年那些天的非做不可，終于和青春一樣，都將在我們的人生中謝幕。t. Baumgartner still will free fall at a speed that would cause you and me to pass out, and no parachute is guaranteed to work higher than 25,000 feet (7,620 meters).cause there25。ll be traveling fast, so despite the distance, it will not be like diving into the deep end of a pool. It will be like he is diving into the shallow end. Skydiver preps for the big jumpWhen he jumps, he is expected to reach the speed of sound 690 mph (1,110 kph) in less than 40 seconds. Like hitting the top of the water, he will begin to slow as he approaches the more dense air closer to Earth. But this will not be enough to stop him pletely.If he goes too fast or spins out of control, he has a stabilization parachute that can be deployed to slow
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