AC power controllers are devices that manage the flow of alternating current (AC) electricity to various electrical loads, such as motors and heaters. They adjust the voltage and current supplied to these devices, allowing for precise control over their operation. This helps improve energy efficiency and can extend the lifespan of the equipment. These controllers often use techniques like phase control or zero-crossing detection to regulate power delivery. By doing so, they minimize energy waste and reduce heat generation, making them essential in applications ranging from industrial machinery to home appliances.