Phase-Locked Double-Loop Speed Regulation of a Temperature controlled Fan

• Main Authors: Chun-wei Li, 李俊韋
• Other Authors: Shiang-Hwua Yu
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/m8jvu8

碩士 === 國立中山大學 === 電機工程學系研究所 === 97 === Cooling fans, widely used in desktop and laptop computers, have been designed toward the tendency of low noise and low consumption power. This thesis purposes a efficient low-noise double-loop control method to regulate the fan speed according to environmental temperature. The proposed controller consists of three parts. The first part is a command generator which generates a train of pulses with its frequency varying proportionally with temperature. The second part is a phase locked loop which intends to synchronize the command pulses with the pulses fed back from the Hall IC of the motor. The third part is an inner loop quantized control that switches the fan according to the error signal sent by the phase locked loop. This double-loop design of feedback achieves accurate fan speed regulation with the nice properties of low noise and high efficiency. The experimental results show an average regulation error of 0.4188% in the fan speed range of 306.6~1953 R.P.M which corresponds to the temperature range 10~70 Celsius.