The Experts below are selected from a list of 82899 Experts worldwide ranked by ideXlab platform

Junming Zhang - One of the best experts on this subject based on the ideXlab platform.

  • an adaptive blanking time control scheme for an audible noise free quasi resonant flyback converter
    IEEE Transactions on Power Electronics, 2011
    Co-Authors: Junming Zhang, Hulong Zeng
    Abstract:

    The quasi-resonant (QR) control scheme is widely adopted in a Flyback converter to maximize its efficiency by reducing the switching loss. The switching frequency increases with decreasing load or increasing Input voltage. In order to limit electromagnetic interference noise and improve light load efficiency, the maximum switching frequency should be limited. However, the maximum switching frequency limitation adopted in QR control will cause audible noise due to the frequency hopping phenomena at certain load and Input Condition, which is related to the intrinsic output characteristic of the control scheme. This paper presents a simple solution to eliminate the frequency hopping in the QR Flyback using an adaptive blanking time circuit. The proposed method changes the blanking time automatically to keep the output characteristic smooth that eliminates the audible noise in the transformer. The detailed operation principle and design considerations are presented. The experimental results from a 16 V/4 A prototype are provided to validate the effectiveness of the proposed solution.

  • An adaptive blanking time control scheme for audible noise free quasi resonant Flyback converter
    2010 IEEE Energy Conversion Congress and Exposition, 2010
    Co-Authors: Zeng Hulong, Junming Zhang, Xiucheng Huang, W. Yuan, Min Chen
    Abstract:

    The quasi resonant (QR) control scheme is widely adopted in Flyback converter to maximize its efficiency by reducing the switching loss. However, the maximum frequency limitation adopted in QR control may cause the audible noise due to the frequency hopping phenomena at certain load and Input Condition, which is related to the intrinsic output characteristic of the control scheme. This paper presents a simple solution to eliminate the frequency hopping in the QR Flyback using an adaptive blanking time circuit. The proposed method changes the blanking time automatically to keep the output characteristic smoothly which eliminate the audible noise in the transformer. The detailed operation principle and design considerations are presented. The experimental results from a 16V/4A prototype are provided to validate the effectiveness of the proposed solution.

Min Chen - One of the best experts on this subject based on the ideXlab platform.

  • An adaptive blanking time control scheme for audible noise free quasi resonant Flyback converter
    2010 IEEE Energy Conversion Congress and Exposition, 2010
    Co-Authors: Zeng Hulong, Junming Zhang, Xiucheng Huang, W. Yuan, Min Chen
    Abstract:

    The quasi resonant (QR) control scheme is widely adopted in Flyback converter to maximize its efficiency by reducing the switching loss. However, the maximum frequency limitation adopted in QR control may cause the audible noise due to the frequency hopping phenomena at certain load and Input Condition, which is related to the intrinsic output characteristic of the control scheme. This paper presents a simple solution to eliminate the frequency hopping in the QR Flyback using an adaptive blanking time circuit. The proposed method changes the blanking time automatically to keep the output characteristic smoothly which eliminate the audible noise in the transformer. The detailed operation principle and design considerations are presented. The experimental results from a 16V/4A prototype are provided to validate the effectiveness of the proposed solution.

Hulong Zeng - One of the best experts on this subject based on the ideXlab platform.

  • an adaptive blanking time control scheme for an audible noise free quasi resonant flyback converter
    IEEE Transactions on Power Electronics, 2011
    Co-Authors: Junming Zhang, Hulong Zeng
    Abstract:

    The quasi-resonant (QR) control scheme is widely adopted in a Flyback converter to maximize its efficiency by reducing the switching loss. The switching frequency increases with decreasing load or increasing Input voltage. In order to limit electromagnetic interference noise and improve light load efficiency, the maximum switching frequency should be limited. However, the maximum switching frequency limitation adopted in QR control will cause audible noise due to the frequency hopping phenomena at certain load and Input Condition, which is related to the intrinsic output characteristic of the control scheme. This paper presents a simple solution to eliminate the frequency hopping in the QR Flyback using an adaptive blanking time circuit. The proposed method changes the blanking time automatically to keep the output characteristic smooth that eliminates the audible noise in the transformer. The detailed operation principle and design considerations are presented. The experimental results from a 16 V/4 A prototype are provided to validate the effectiveness of the proposed solution.

Fucheng Zhang - One of the best experts on this subject based on the ideXlab platform.

  • effect of welding heat Input and post welding natural aging on hardness of stir zone for friction stir welded 2024 t3 aluminum alloy thin sheet
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2013
    Co-Authors: Ruidong Fu, Ju Kang, Yijun Li, Jianfeng Zhang, Fucheng Zhang
    Abstract:

    The hardness of stir zone (SZ) at as-weld state and post-welding natural aging (PWNA) state under different heat Input Conditions were investigated for friction stir-welded joints of 2024 aluminum alloy thin-sheets. Results show that welding heat Input has obvious effect on the hardness of the SZ. Under the high welding heat Input Condition, the hardness of the SZ is lower than that of the base metal (BM). However, under low welding heat Input Condition, the hardness of the SZ exhibits strong dependency on the rotational speed of the stirring tool. With increasing the rotational speed of the stirring tool, the hardness of the SZ increases. The average hardness in the SZ of the joint welded at 1500 rpm and 1000 mm/min achieves the BM level. In comparison, the effect of the PWNA on the improvement of the hardness in the SZ is limited. The variation in the strengthening-phase particles plays a more important role than does grain size in the SZ for the improvement of hardness.

Zeng Hulong - One of the best experts on this subject based on the ideXlab platform.

  • An adaptive blanking time control scheme for audible noise free quasi resonant Flyback converter
    2010 IEEE Energy Conversion Congress and Exposition, 2010
    Co-Authors: Zeng Hulong, Junming Zhang, Xiucheng Huang, W. Yuan, Min Chen
    Abstract:

    The quasi resonant (QR) control scheme is widely adopted in Flyback converter to maximize its efficiency by reducing the switching loss. However, the maximum frequency limitation adopted in QR control may cause the audible noise due to the frequency hopping phenomena at certain load and Input Condition, which is related to the intrinsic output characteristic of the control scheme. This paper presents a simple solution to eliminate the frequency hopping in the QR Flyback using an adaptive blanking time circuit. The proposed method changes the blanking time automatically to keep the output characteristic smoothly which eliminate the audible noise in the transformer. The detailed operation principle and design considerations are presented. The experimental results from a 16V/4A prototype are provided to validate the effectiveness of the proposed solution.