An AC-DC power module is a compact electronic device that converts alternating current (AC) from the mains supply into direct current (DC) suitable for electronic equipment. It typically accepts an input voltage in the range of 85–264 VAC or 90–305 VAC, allowing operation in both 50 Hz and 60 Hz power systems. The output is a regulated DC voltage, commonly 5 V, 12 V, 24 V, or higher, depending on the application requirements. By providing a stable and reliable DC source, the module acts as a crucial interface between the power grid and sensitive electronic circuits.Internally, an AC-DC power module usually consists of several functional stages. The input stage includes a fuse, surge protection components, and an electromagnetic interference filter to meet safety and EMC standards. This is followed by a rectifier and a high-frequency switching stage that convert AC into a controlled DC output. Modern designs often use high‑efficiency topologies and advanced control ICs to reduce power loss and improve performance. Many modules also incorporate power factor correction to minimize harmonic distortion on the AC line.Protection features are an important aspect of AC-DC power modules. Typical protections include over‑voltage protection, over‑current protection, short‑circuit protection, and over‑temperature shutdown. These functions help protect both the power module and the connected load from abnormal operating conditions. Isolation between input and output, usually provided by a high‑frequency transformer, enhances safety and allows the module to meet international standards such as IEC and UL for reinforced or basic insulation.AC-DC power modules are widely used in industrial control, communication systems, instrumentation, home appliances, LED lighting, and IoT devices. Their compact size and standardized footprints enable easy integration into printed circuit boards or system enclosures. Many models are available in open‑frame, encapsulated, or metal‑enclosed formats, with options for chassis mounting, DIN‑rail mounting, or direct PCB mounting.Energy efficiency and thermal management are key design considerations. High‑efficiency modules reduce heat generation, enabling operation in confined spaces and extending the life of surrounding components. Some modules are designed to operate over a wide temperature range and in harsh environments, featuring conformal coating or enhanced insulation. With ongoing advances in semiconductor technology and circuit design, AC-DC power modules continue to evolve toward higher efficiency, higher power density, and greater reliability, supporting the growing demand for compact and energy‑saving electronic systems.