What device limits voltage spikes by discharging or bypassing surge current?

A surge protector is designed specifically to limit voltage spikes by discharging or bypassing surge current. When there is a sudden increase in voltage—often caused by events like lightning strikes or power surges—the surge protector redirects the excess energy away from sensitive electronics and electrical systems. This diversion prevents damage to the devices connected to the power source.

Surge protectors typically use components such as metal oxide varistors (MOVs) to sense the voltage level and act quickly to protect connected devices. They act as a first line of defense against voltage transients, ensuring that normal operating levels are maintained and protecting equipment from potential harm.

In contrast, devices like voltage regulators primarily manage and maintain a consistent voltage level rather than dealing directly with spikes. Circuit breakers and fuses serve to interrupt the electrical flow in the case of overloads or faults but do not specifically mitigate the impact of transient voltage spikes. Thus, the surge protector is the appropriate answer to this question, as its primary function is to handle and mitigate those harmful voltage surges directly.