Design of a battery operated portable DC power supply. Part 2 : output current monitoring and protection

• Main Author: Fu, Xinyu
• Other Authors: Chen Tupei
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2021
• Subjects: Engineering::Electrical and electronic engineering
• Online Access: https://hdl.handle.net/10356/149089
• Institution: Nanyang Technological University

Nowadays, we are living in a world surrounded by electrical appliances. These appliances have greatly improved the quality of our life in many ways. As the source of power that operate these products, electricity is becoming one of the most important energy in our daily life. In all electrical products, overcurrent protection is taking a significant role to ensure the safety of users and assure the reliability of electrical product. As the technology developed, the electrical appliance is becoming more portable and affordable to the consumers, and hence, leads to a high demand in portable DC power supply. Typically, overcurrent protection for low voltage appliances can be achieved by applying a fuse in the circuit. However, the disadvantage is that fuse require replacement after a fault occurs, which bringing extra cost to user. The aim of this project is to design a cheap and reusable overcurrent protection circuit, which able to isolate the connection between DC power supply and load during overcurrent condition, thus, safeguard the user from fault current. This report proposed an integrated overcurrent protection circuit with current monitoring function. The output current from DC power supply is constantly monitored to detect overcurrent condition. Once the output current is higher than the pre-set limit, the power supply will be cut off to isolate the fault. This report introduced the hardware and software applied to implement this project.