Jian-Hua Duan

Title: Innovations of Jian-Hua Duan

Introduction

Jian-Hua Duan is a notable inventor based in Shanghai, China. He has made significant contributions to the field of electronics, particularly in the development of circuits and power adapters. With a total of 2 patents, his work showcases innovative solutions to common electrical challenges.

Latest Patents

One of Jian-Hua Duan's latest patents is a "Short circuit protection circuit for a pulse width modulation (PWM) unit." This invention includes a PWM logic control circuit, an under voltage lookout (UVLO) circuit, and an internal clock circuit. The UVLO circuit detects a bias power (Vcc) and delivers a UVLO signal when the bias power is judged excessively low. The PWM unit further comprises a short circuit detector, a short circuit recovery circuit, and a frequency multiplexer. The short circuit detector generates a short signal upon detecting the UVLO signal, while the recovery circuit sets a predetermined recovery time to generate a recovery signal when the time ends. The frequency multiplexer changes the switching frequency to a short PWM frequency during a short circuit event and restores it when the recovery signal is triggered.

Another significant patent is for a "Power adapter with voltage-stabilized compensation." This power adapter features a pulse frequency modulation circuit that generates a driving pulse with a variable OFF time interval to control the power transformed and output by a transformer. It includes an ancillary coil to induce a feedback signal on the secondary coil of the transformer. The pulse frequency modulation circuit consists of a time interval modulation unit that receives the feedback signal and a feedback compensation unit. The time interval modulation unit generates a sample signal to modulate the OFF time interval, while the feedback compensation unit provides a compensation signal to adjust the feedback or sample signal, thereby stabilizing the voltage output from the secondary side.

Career Highlights

Jian-Hua Duan is currently employed at BCD Semiconductor Manufacturing Limited, where he continues to innovate and develop new technologies. His work has had a significant impact on the electronics industry, particularly in enhancing the efficiency and reliability of power management systems.

Collaborations

Throughout his career, Jian-Hua has collaborated with talented individuals such as Shao-Hua Fang and Chao Chen. These collaborations have contributed to the successful development of his patents and innovations.

Conclusion

Jian-Hua Duan is a