What type of motor can operate on both AC and DC?

The universal motor is designed to operate on both alternating current (AC) and direct current (DC). This versatility stems from its construction, which includes brushes and a wound armature. When connected to a DC supply, it functions similarly to a series motor, drawing current through both the armature and field windings, enabling it to produce torque and rotate. When supplied with AC, the motor can also operate effectively due to its design, which provides a rotating magnetic field that works in conjunction with the alternating input.

The universal motor is particularly useful in applications where varying speeds are required, such as in power tools and household appliances, due to its ability to operate efficiently across both types of current. This characteristic makes it distinct from other motor types that are typically limited to one form of power supply, enhancing its utility in various electrical applications.