Power frequency converters take electrical input power at one frequency and voltage and provide electrical output power at a different frequency and at a different or equal voltage.
Power transformers convert power-level voltages from one level or phase configuration to another. They can include features for electrical isolation, power distribution, and control and instrumentation applications.
Voltage regulators are power converters that provide voltage control capabilities. They accept a voltage that varies over a given range and generate an output voltage that does not vary.