Every Electronic Device, has to be either directly plugged into a power source or operate from a battery source which makes it mandatory to have some level of Power Supply Circuit within it. Depending on the application these circuits can be a simple, AC-DC Converter, DC-DC Converter or a Battery Charger.  In this section we will design and test various types of power supply circuits that can fit into a wide verity of applications including SMPS Power Supplies, LED Drivers, Battery Chargers etc. Each article includes a well-illustrated circuit diagrams and hardware demonstration to help the readers to build and evaluate their own designs.