本論文主要研製主動箝位返馳式轉換器，並與傳統的返馳式轉換器做比較。主動箝位返馳式轉換器利用主動箝位電容，吸收變壓器漏感的能量，以消除開關上的電壓突波，同時利用諧振達到開關零電壓切換，藉以提升轉換器效率。且主動箝位返馳式轉換器在輕載時為連續導通模式，同步整流較容易實現。本論文針對具同步整流主動箝位返馳式轉換器之動作原理進行討論，實際完成一組輸入電壓範圍90Vac~264Vac、輸出為19V/45W、滿載效率89.5%的電源轉換器。

This thesis focuses on the study and implementation of an active-clamp flyback converter, and compare it to a conventional flyback converter. The active-clamp flyback converter uses a capacitor to absorb the leakage inductor energy of the transformer and eliminate the voltage spike when the switch is turned off. Also the zero-voltage switching is achieved by the resonant tank to raise the conversion efficiency. The discussed active-clamp flyback converter is operated under CCM at light load. Therefore, the synchronous rectification is easier to fulfill. The operating principles are discussed. A prototype converter with an input AC voltage range from 90 Vac to 264 Vac and an output of 19 V/45 W is implemented and tested. The efficiency at rated load is 89.5%.

[1] P. Alou, O. Garcia, J. A. Cobos, J. Uceda, and M. Rascon, “Flyback with active clamp: a suitable topology for low power and very wide input voltage range applications, ” IEEE Applied Power Electronics Conf, vol. 1, pp. 242-248, 2002.
[2] C. T. Choi, C. K. Li, and S. K. Kok, “Control of an active clamp discontinuous conduction mode flyback converter,” IEEE Power Electronics and Drive Systems, vol. 2, pp. 1120-1123, 1999.
[3] 林昕立，「新型同步整流技術之研究」，國立台灣科技大學電子工程系研究所碩士論文。民國102年。
[4] G. Hua, C.S. Leu, and F. C. Lee, “Novel zero-voltage-vansiton PWM converters,” IEEE Power Electronics Specialists Conf, Proc, 1992.
[5] 梁適安，交換式電源供應器設計實務，文笙書局股份有限公司。民一百零一年七月。
[6] 吳義利，切換式電源轉換器，全華科技圖書股份有限公司。民八十三年八月。
[7] 林景源，「雙變壓器主動箝位順向式與返馳式轉換器」，國立台灣科技大學電子工程系研究所博士論文。民國96年。
[8] 鄭玉南，「返馳式轉換器緩振電路研究」，國立台灣科技大學電子工程系研究所博士論文。民國95年。
[9] 王釗桴，「單級雙變壓器主動箝位返馳式轉換器研製」，國立台灣科技大學電子工程系研究所碩士論文。民國99年。
[10] 陳家麟，「具功率修正因數主動箝位返馳式轉換器研製」，國立台灣科技大學電子工程系研究所碩士論文。民國96年。
[11] Y.S. Lee, and B.T. Lin, “Adding active clamping and soft switching to boost-flyback single-stage isolated power-factor-corrected power supplies,” IEEE Transactions　on Power Electronics, vol. 12, no. 6, pp. 1017-1027, 1997.
[12] Y. Hakoda, T. Ninomiya, M. Shoyama, and T. Hashimoto, “Effect of clamp capacitor on the stability of active-clamp dc-dc converters,” IEEE Applied Power Electronics Conference Proc, pp. 354-361, 1998.
[13] W. A. Tabisz, M. M. Jovanovic, F. C. Lee, “Present and future of distributed power systems,” IEEE Applied Power Electronics Conference Proc, pp. 11-18, 1992.
[14] R. Erickson, M. Madigan, and S. Singer, “Design of a simple high power-factor　rectifier based on the flyback converter, ” IEEE Applied Power Electronics Conf. Proc, pp. 792-801, 1990.
[15] Texa instruments, “TL494 pulse width modulation control circuits,” datasheet, 1999.
[16] Fairchild, “CD4069UBC inveter circuits,” datasheet, 1987.
[17] C. Y. Lin, R. Farrington, W. A. Tabisz, F. C. Lee, “Development of a high-voltage CRT power supply,” VPEC Power Electronics Seminar Proc, pp. 143-149, 1992.
[18] J. Feng, Y. Hu, W. Chen, and C. C. Wen, “ZVS analysis of asymmetrical half-bridge converter,” IEEE Power Electronics and Drive Systems, vol. 1, pp. 243-247, 2001.
[19] K. Yoshida, T. Ishii, and N. Nagagata, “Zero voltage switching approach for flyback converter,” in Proc. 14th lnt.Telecomm. Energy Conf, pp. 323-329, 1992.
[20] K. Harada and H. Sakamoto, “Switched snubber for high frequency switching,” Proc. Power Electron. Spec. Conf, pp. 181-187, 1990.
[21] A code jiangmen electionics , “Products Selection,” datasheet, 2012.