本論文主要探討不同的切換頻率對切換式電源供應器中變壓器的影響,其目的是提高切換頻率來減少變壓器需要的感量藉以降低其尺寸與大小,其中分別利用順向式轉換器和返馳式轉換器來完成驗證,電路中使用UC3845控制晶片來達到50 kHz以及100 kHz兩種不同的切換頻率。 本論文首先介紹兩種架構的轉換器的原理,其次則詳述設計步驟並且列出所需要之元件規格,最後依照設計結果完成輸入電壓為48伏特,輸出電壓為12伏特且輸出功率為12瓦特之轉換器,同時量測其波形,最後比較切換頻率對變壓器體積與轉換器的影響,結果顯示增加切換頻率可大幅減少轉換器的體積並可藉此提高轉換器的功率密度。
ABSTRACT This thesis probes into the different switching frequency over to the influence of magnetic component in power supply mainly, its purpose is to improve switching frequency to reduce the inductance that converter need and use to reduce the converter size, among them make use of forward and fly-back converters to finish verifying separately, use control IC UC3845 to reach 50 kHz and 100 kHz two kinds of different switching frequency over in the circuit, At first, in thesis will analyze of the movement principle to the converters of two kinds of structure, Secondly, narrate the step of designing in detail and list the component specifications needed to use, At last, according to the design procedure stipulated,finish the operation of the specifications are as follows: input voltage = 48 V, output voltage = 12 V, output current = 1 A and output power = 12 W is built, At the same time quantity examines its wave form result, Then, compare the size of magnetic component in power supply in different switching over the difference under frequency.