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轉(zhuǎn)換比率:金額 X 10=金幣數(shù)量, 例100元=1000金幣 | 論文字?jǐn)?shù):8665 | ![]() | |
折扣與優(yōu)惠:團(tuán)購(gòu)最低可5折優(yōu)惠 - 了解詳情 | 論文格式:Word格式(*.doc) | ![]() |
摘要:本設(shè)計(jì)主要由三部分構(gòu)成,即:整流濾波電路、輔助電源電路、DC-DC變換及保護(hù)電路。先將220V的輸入電壓經(jīng)過(guò)隔離變壓后得到15V的交流電壓,再將15V的交流電通過(guò)整流濾波后得到的20-30V直流電作為輸入電源。主控制電路以芯片TL494為核心,其中PWM控制信號(hào)由TL494產(chǎn)生, DC-DC變換器采用推挽式變換方式,輸出的高頻PWM波通過(guò)高頻變壓器變壓輸出,再將其通過(guò)整流濾波后既可輸出穩(wěn)壓直流電。采用硬件反饋方式將直流電反饋到TL494的誤差放大器,使其能夠自動(dòng)調(diào)節(jié)PWM波的占空比并穩(wěn)定輸出電壓。設(shè)計(jì)出適合整個(gè)設(shè)計(jì)要求的主電路結(jié)構(gòu),并在此基礎(chǔ)上設(shè)計(jì)出保護(hù)電路、驅(qū)動(dòng)電路,使電源工作在一個(gè)穩(wěn)定的系統(tǒng)。根據(jù)設(shè)計(jì)要求以及主電路的結(jié)構(gòu),對(duì)電路中各參數(shù)進(jìn)行計(jì)算。最后對(duì)電路進(jìn)行測(cè)試,并根據(jù)其結(jié)果進(jìn)行改進(jìn)。 關(guān)鍵詞:開(kāi)關(guān)電源;TL494;PWM;DC-DC變換器;穩(wěn)壓
ABSTRACT:The design is mainly made up of three parts, namely: rectified filter circuit, auxiliary power circuits, DC-DC converter and its protection circuit. After isolation transformer are 15V input voltage of 220V AC voltage, 15V AC rectifier filtering after the adoption of the resulting 20-30V DC input power supply. Main control circuit TL494 chip as the core, with PWM control signal generated by the TL494, DC-DC converter using push-pull converter, high frequency PWM waves output through the HF transformer transformer output, then through rectifier filtering it can output regulated DC power. Hardware feedback DC feedback to TL494 error amplifier, enabling it to automatically adjust the PWM duty cycle and stabilizing the output voltage of the wave. Design of main circuit structure for the entire design requirements, on the basis of design protection circuit, driving circuit, the power supply in a stable system. According to the design requirements and main circuit structure, to calculate the arguments in circuit. Last test on the circuit, and improve it according to its results. Key words: Switching power supply; TL494; PWM;DC-DC converter; stabilivolt
電源是一切電子設(shè)備的心臟部分,其質(zhì)量的好壞直接影響電子設(shè)備的可靠性。而開(kāi)關(guān)電源更為如此,越來(lái)越受到人們的重視。目前的計(jì)算機(jī)設(shè)備和各種高效便攜式電子產(chǎn)品發(fā)展趨于小型化,其功耗都比較大,要求與之配套的電池供電系統(tǒng)體積更小、重量更輕、效率更高,必須采用高效率的DC-DC開(kāi)關(guān)穩(wěn)壓電源。在開(kāi)關(guān)電源DC-DC變換器中,由于輸入電壓或輸出端負(fù)載可能出現(xiàn)波動(dòng),應(yīng)保持平均直流輸出電壓應(yīng)能夠控制在所要求的幅值偏差范圍內(nèi),需要復(fù)雜的控制技術(shù),于是各種 PWM控制結(jié)構(gòu)的研究就成為研究的熱點(diǎn)。在這樣的前提下,設(shè)計(jì)開(kāi)發(fā)開(kāi)關(guān)電源DC-DC控制芯片,無(wú)論是從經(jīng)濟(jì),還是科學(xué)研究上都是很有價(jià)值的。
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