Huang, C.H. Cheng, Y.-S. Chiu, P.C. Hsu, K.T. Hu, K.H. Wu, C.Y. JACoW Publishing Geneva, Switzerland 978-3-95450-200-4 10.18429/JACoW-PCaPAC2018-THCA3 English 127-130 THCA3 power-supply feedback radio-frequency controls photon Contribution to a conference proceedings 2019 2019-01 https://doi.org/10.18429/JACoW-PCaPAC2018-THCA3 http://jacow.org/pcapac2018/papers/thca3.pdf For a low-emittance photon light source like the Taiwan Photon Source (TPS), beam stability is a very important property for high-quality photon beams. It is, however, hard to completely remove beam disturbing effects. Therefore, a feedback/feedforward system becomes an effective tool to suppress beam motion. In this report, we discuss the performance of such a system implemented at the TPS. The component performance of the feedback system has been tested to understand its bandwidth limitations.