A Simple Device to Simulate the Working Principle of an Inverter

Many electrical devices based on Faraday's Law of Induction require alternating current (AC) rather than direct current (DC) from batteries or solar energy. In the early days, DC to AC conversion was achieved mechanically, such as rotary converters, which mounted a DC motor and an AC generator on the same rotating shaft. With the development of power electronics, static inverters based on high-frequency semiconductor switching devices such as Insulated Gate Bipolar Transistors (IGBTs) or Metal Oxide Semiconductor Field Effect Transistors(MOSFETs) can convert DC to AC through high-frequency switching action efficiently.1 As a result, the bulky and expensive transformers and inductors in traditional low-frequency inverters can be replaced by smaller, lighter, and lower-cost components. Modern inverters have eliminated the need for brushes in many DC motors. Moreover, they are critical for renewable energy. For instance, a solar power generation system generates direct current, which needs to be fed into an alternating current power grid through large inverters. While modern inverters accomplish DC to AC conversion with sophisticated electronics, students often struggle to visualize how a variable current can be derived from a constant source. In response to these challenges, this paper presents a simple device that simulates the working principle of an inverter using mechanical actions. This device provides an intuitive physical analogy for the critical role of the magnetic flux change rate in electromagnetic induction and simulates an inverter's working principle.