A power supply is a device that provides power to electronic equipment, also known as a power supply, which provides the electrical energy required by all components in a computer. The size of the power supply, whether the current and voltage are stable, will directly affect the working performance and service life of the computer. High-quality power supplies generally have multi-national certification marks such as FCC, UL and Great Wall of China. These certifications are professional standards formulated by certification bodies for power supplies according to the technical specifications in the industry, including production process, electromagnetic interference, safety protection, etc. All products that meet certain indicators can only use certification marks on packaging and product surfaces after they have passed the declaration and certification. have a certain authority. The new power supply IC has complete protection measures, including: output overcurrent limit, overheat protection, short circuit protection and reverse battery polarity protection, so that the power supply is safe and reliable, and not easy to damage. Many portable electronic products have single-chip microcomputers. When the output voltage of the power supply drops by a certain percentage due to overheating or low battery voltage, the power supply IC has a power supply working status signal that is sent to the single-chip computer to reset the single-chip computer. This signal can also be used to indicate the working status of the power supply (when the battery is low, there is an LED display).