What component will cause a generator to produce DC voltage instead of AC?

The commutator is a crucial component in a generator designed to produce direct current (DC) voltage. It functions by reversing the direction of the current flow through the rotor windings every half turn, ensuring that the output remains in one direction. This is essential for converting the alternating current (AC) generated in the windings — which naturally fluctuates in direction — into a steady direct current that can be used in applications requiring consistent voltage polarity.

In contrast, components such as rectifiers are also associated with changing AC to DC, but they serve a different role and are typically employed in conjunction with an AC source. Transformers serve to change voltage levels in AC systems and do not convert AC to DC. Capacitors are used for various functions, including filtering and energy storage, but they don't inherently change the nature of the current from AC to DC. Therefore, the commutator is essential for the direct conversion process within the generator itself.