Isolation transformers adjust voltage output by altering the voltage input according to the required voltage, current, and turns ratio. In single-phase AC systems, voltage fluctuations occur simultaneously, making it less suitable for powering large motors and industrial machinery. In contrast, three-phase power uses three distinct signals, each with a separate peak time, which helps to eliminate the oscillations present in single-phase systems. This results in smoother operation, reduced vibration, and simplified equipment design, making three-phase electricity more effective for powering large motors and heavy industrial equipment.