What commonly causes transient voltages?

What commonly causes transient voltages?

• A. Contact bounce
• B. Lightning surges
• C. Harmonics
• D. Voltage sags

Answer: (A)

Transient voltages are brief spikes that happen when a circuit switches suddenly. Contact bounce occurs when a mechanical switch or relay makes and breaks contact multiple times in a very short time as it settles. Each rapid transition can push current through inductive elements and create a short, sharp excursion in voltage. Because switches are used so frequently in control circuits, this bouncing is a very common source of transient voltages. By contrast, lightning surges are large, external events that happen during storms and are not as routinely encountered in everyday operation. Harmonics distort the waveform due to non-linear loads rather than producing quick voltage spikes, and voltage sags are dips in voltage, not spikes.

Transient voltages are brief spikes that happen when a circuit switches suddenly. Contact bounce occurs when a mechanical switch or relay makes and breaks contact multiple times in a very short time as it settles. Each rapid transition can push current through inductive elements and create a short, sharp excursion in voltage. Because switches are used so frequently in control circuits, this bouncing is a very common source of transient voltages. By contrast, lightning surges are large, external events that happen during storms and are not as routinely encountered in everyday operation. Harmonics distort the waveform due to non-linear loads rather than producing quick voltage spikes, and voltage sags are dips in voltage, not spikes.