A power circuit is any circuit used to carry electricity that operates a load. It’s important to distinguish power circuits from control circuits since they have different capabilities. Transformers, motors, generators, switches, and circuit breakers are all important elements of a power circuit.
Most lighting receptacle outlet circuits in houses are power circuits since they only provide power to devices when they are operating. In other types of power circuits, the transformer can step or down the voltage of the signal, motors and generators can convert electrical energy into mechanical energy, and switches and breakers regulate the flow of electrical energy, protecting from overloads or short circuits.
When selecting a power circuit, consider the power requirements for the load in both voltage and current, the physical size and efficiency, as well as the noise immunity of the system.