What does a surge protector do?

A surge protector is designed specifically to protect electrical devices from voltage spikes, which can occur due to various reasons such as lightning strikes, power surges from the utility company, or sudden changes in power demand. When a voltage spike occurs, the surge protector absorbs the excess voltage and prevents it from reaching connected devices, thus safeguarding them from potential damage.

The primary function of a surge protector is to ensure that the voltage supplied to sensitive electronics remains within safe levels, effectively acting as a buffer against sudden increases in electrical current. This not only helps in prolonging the lifespan of devices but also maintains their proper functioning.

The other options focus on different concepts: redirecting spikes, regulating voltage, or providing backup power. While redirecting voltage spikes into the ground is part of how surge protectors work (specifically in some designs), the main purpose is to protect devices. Regulating the main voltage supply is a function of voltage regulators, and serving as a backup power source is the role of uninterruptible power supplies (UPS), neither of which directly describes the surge protectors' main function.