基于tl431的反激式開關(guān)電源設(shè)計學(xué)士畢業(yè)論文-全文預(yù)覽
【正文】 。與線性電源相比，PWM開關(guān)電源更為有效的工作過程是通過“斬波”，即把輸入的直流電壓斬成幅值等于輸入電壓幅值的脈沖電壓來實現(xiàn)的。3) 檢測電路 通過電路檢測得到的正在運(yùn)行中各種參數(shù)和各種儀表數(shù)據(jù)提供給保護(hù)電路。1) 主電路 沖擊電流限幅：限制接通電源瞬間來自電網(wǎng)的浪涌電流。在相同的紋波輸出電壓的要求下，采用開關(guān)穩(wěn)壓電源時，濾波電容的容量大大的縮小了。當(dāng)工頻電網(wǎng)電壓變化較大或者負(fù)載變化較大時，開關(guān)電源的輸出電壓任然能夠高效穩(wěn)定的輸出，因為輸出電壓的變化可以通過占空比或調(diào)整脈沖寬度來調(diào)節(jié)。使得功率管的功耗小，因此電源的效率也得到了很大的提高。開關(guān)電源的基本構(gòu)成DC/DC變換器進(jìn)行功率轉(zhuǎn)換，它是開關(guān)電源的核心部分，此外還有啟動、過流與過壓保護(hù)、噪聲濾波等電路。feedback circuit目次1 緒論…………………………………………………………1 開關(guān)電源簡介…………………………………1 開關(guān)電源基本原理……………………………22 基于TL431的反激式開關(guān)電源設(shè)計………………………4 TL431簡介……………………………………4 PC817簡介……………………………………63 反激式開關(guān)電源設(shè)計………………………………………8 反激式開關(guān)電源主電路………………………8 反饋電路………………………………………11 電路檢測………………………………………14 輔助電源………………………………………204 測試方法與數(shù)據(jù)……………………………………………21 測試方法與數(shù)據(jù)…………………………………21結(jié)論……………………………………………………………23參考文獻(xiàn)……………………………………………………………24致謝…………………………………………………………… 25 IV 1 緒論 開關(guān)電源簡介 整個通信系統(tǒng)的動力源是開關(guān)電源系統(tǒng)，開關(guān)電源系統(tǒng)也被稱為通信系統(tǒng)的“心臟”，可見他占有極其重要的地位。關(guān)鍵詞 開關(guān)電源；反激式；TL431；UC3842；反饋電路 The flyback type switch power supply design based on TL431Zhang Mingzhi School of Physics and Electronic Information, Huai Bei Normal University, Anhui Huaibei, 235000Abstract A high precise and reliable singleended flyback switching power supply was designed and made in this paper,whose current controller consisted of alinear photoelectric couple. The closedloop feedback of TL431 was used to realize switching power supply’s stable with general switching power supply, the power’s had been with the advantages of high switch frequency,small switch loss, high reliability and so the rapid development of Information Technology,the flyback switching power supply was used widely in low power design and application of a new singleoutput single flyback switching power supply was proposed in this paper had been analyzed flyback switching power supply of their working principle and the basic knowledge ,and introduced a few major chip functions and the use of the pin and the research course,the realization of the feedback circuit based on TL431 and PC817 was presented in the unconventionaloutput and singleended flyback switching power supply was designed and made in this paper,whose the basic principle consists of the flyback type switch power article had been introduced an unconventional flyback power flyback power supply had been with the advantage of output current large and stable , we can also use the small power electrical appliances in the daily life,which we will make according to the principle of the flyback switching power supply in this power.Keywords Switching power supply。 隨著信息技術(shù)的迅速發(fā)展，反激式開關(guān)電源適用于小功率場合且易于推廣使用。反激式開關(guān)電源的優(yōu)點(diǎn)是其電路簡單、體積小便于攜帶、輸出電壓穩(wěn)定性高。同時，我們還可以根據(jù)本論文的設(shè)計原理通過改變占空比和芯片外圍電阻值制作不同輸出的開關(guān)電源（輸出功率要在100W以內(nèi)），供應(yīng)日常生活的小功率電器使用。UC3842。開關(guān)電源采用功率半導(dǎo)體器件作為開關(guān)器件，通過周期性間斷工作，控制開關(guān)器件的占空比來調(diào)整輸出電壓。再有信號激勵的情況下,功率晶體管在飽和導(dǎo)通與截止的卡愛管狀態(tài)交替工作,轉(zhuǎn)換頻率可以達(dá)到幾十到幾百kHz。3) 穩(wěn)壓范圍寬。開關(guān)穩(wěn)壓電源的工作頻率目前基本上是工作在50kHz，濾波的效率大為提高。 開關(guān)電源基本原理1. 開關(guān)電源大至由主電路、控制電路、檢測電路、輔助電源四大部份組成。2) 反饋電路 經(jīng)過輸出端得到的采樣電壓與基準(zhǔn)電壓進(jìn)行比較后，使得反饋電路起到對電源的保護(hù)作用，使得開關(guān)電源電壓穩(wěn)定輸出。 在線性電源中，讓功率晶體管工作在線性模式，與線性電源不同的是，PWM開關(guān)電源是讓功率晶體管工作在導(dǎo)通和關(guān)斷的狀態(tài)，在這兩種狀態(tài)中，加在功率晶體管上的伏安乘積是很小的（在導(dǎo)通時，電壓低，電流大；關(guān)斷時，電壓高，電流小）/功率器件上的伏安乘積就是功率
環(huán)評公示相關(guān)推薦
鄂ICP備17016276號-1