Which component protects against transient voltages in the power input module?

• A. Power switch
• B. Fuses
• C. Transient suppression circuitry
• D. Ventilation fan

Answer: (C)

Protecting against brief voltage spikes is the job of transient suppression circuitry. Transient voltages are short, high-energy spikes that can come from switching events, lightning, or grid faults, and they can damage sensitive electronics if not kept in check. The transient suppression circuitry clamps or diverts these spikes to safe levels, often using devices like MOVs or TVS diodes that react in nanoseconds to absorb or shunt the excess energy. This keeps the power input clean and protects downstream components.

A power switch only controls whether power is connected; it doesn’t limit or absorb spikes. Fuses provide overcurrent protection by opening the circuit after a fault, but they don’t clamp transient voltages and may react too slowly to protect sensitive parts. The ventilation fan is for cooling and has no role in voltage transient protection.