Hong-Shi Chang

Title: Innovations of Hong-Shi Chang

Introduction

Hong-Shi Chang is a notable inventor based in Hsinchu, Taiwan. He has made significant contributions to the field of brushless DC motor technology, holding a total of 4 patents. His work focuses on enhancing the efficiency and control of electric motors, particularly in applications such as electric motorcycles.

Latest Patents

One of his latest patents is a brushless DC motor speed controller. This invention provides a method for obtaining the speed feedback signal necessary for speed control from the commutation signals generated by the magnetic-pole sensor in the brushless DC motor. The speed controller includes an edge detector that generates a pulse each time a rising or falling edge is detected in the signal from the magnetic-pole sensor. A frequency multiplier is utilized to multiply the frequency of the pulse train from the edge detector. Additionally, a frequency-to-voltage converter transforms the output pulse train into a positive analog voltage, which is proportional to the speed of the brushless DC motor. The invention also features a motor rotating direction detecting circuit that determines the current rotation direction of the motor. A feedback signal polarity analog multiplexer generates a positive or negative analog voltage as a speed feedback signal based on the detected rotation direction. Furthermore, a speed compensator controls the level of the DC voltage supplied to the motor based on the speed command input and feedback signal.

Another significant patent is a torque control method and device for brushless DC motors used in electric motorcycles. This invention employs a single current loop to obtain feedback current from a DC bus, simplifying the circuit's construction. The device operates using two input signals: a torque command signal to generate positive torque and a brake command signal to generate negative torque. This allows for effective control of the braking command and energy storage during braking, while also stopping the motor's rotation within 120 degrees of its electrical angle of reversed rotation.

Career Highlights

Hong-Shi Chang is affiliated with the Industrial Technology Research Institute, where he continues to innovate and develop advanced technologies in motor control. His work has significantly impacted the efficiency and performance of electric motors, contributing to the advancement of electric vehicle technology.

Collaborations

He has collaborated with notable colleagues, including Tshaw-Chuang Chen and Huan-Jen Yang, who have contributed to his research and development efforts.

Conclusion

Hong-Shi Chang's contributions to