A transient is a temporary spike or surge in voltage or current that can affect a circuit in a variety of ways from minor failures to catastrophic failures. Transient voltages can range from a few millivolts to a few thousand volts, and can last from a few nanoseconds to a few hundred milliseconds. Some transients are repetitive, such as those caused by inductive ringing in an electric motor, while others are episodic, such as ESD events.

Shanghai instantaneous voltage suppressor