In modern electronic devices, the Switching Mode Power Supply (SMPS) is an essential energy conversion system. One of its most critical components is the switching power controller IC . Among various options, the TOPSwitch series by Power Integrations stands out for its high integration and efficiency. Specifically, the TOP248YN is a widely adopted model for medium- and small-sized power supplies.     This post will explore the internal structure and operation of the TOP248YN and explain how it is applied in real-world circuit designs. 1. Introduction to TOP248YN TOP248YN is a highly integrated switching power solution that combines a PWM controller and high-voltage MOSFET into a single chip. It accepts an AC input of 85–265V and outputs various DC voltages, supporting up to 65W under preheat conditions. Manufacturer: Power Integrations Package: TO-220-7C Built-in functions: high-voltage MOSFET, current limit, oscillator, feedback contro...

Every time we power on a computer, a hidden component quietly starts spinning—the hard disk drive (HDD) motor. Often seen as a simple storage device, the HDD actually houses a high-performance, high-speed brushless DC (BLDC) motor that is durable, precise, and incredibly well-suited to become a powerful DIY rotary tool. Transforming a discarded hard drive into a practical, fast-spinning tool is easier than most think. With just a few electronic components and minor mechanical work, you can breathe new life into what would otherwise be e-waste. Thanks to the rise of affordable ESCs (Electronic Speed Controllers), even those without a deep electronics background can build their own high-speed cutting or polishing tool.     Understanding the Anatomy of a Hard Disk Drive Every hard drive consists of three key parts: 1) the platters where data is stored, 2) a motor that spins the platters, and 3) the actuator arm with a read/write head. For our purpose, w...