Definition
A transient, often called a voltage spike or surge, is a very short, sharp deviation from the normal waveform. IEEE 1159 splits transients into two types. An impulsive transient is a unidirectional spike, positive or negative, that rises and falls in microseconds, such as the disturbance from a nearby lightning strike or electrostatic discharge. An oscillatory transient swings rapidly above and below normal voltage in a damped ringing, typically from switching events like energizing a capacitor bank.
Magnitude and duration
Transients can range from a few volts to several thousand volts and last from under a microsecond to a few milliseconds. A classic impulsive test waveform, the 1.2 by 50 microsecond impulse, rises to peak in 1.2 microseconds and decays to half-peak in 50 microseconds. Despite their brevity, the high instantaneous energy can puncture insulation and destroy semiconductor junctions.
Protecting mining hardware
ASIC power supplies and control boards are vulnerable to transients that exceed their input clamping. Surge protective devices, metal-oxide varistors, proper bonding, and good grounding divert transient energy before it reaches sensitive electronics. In a hashcenter, transients from switching large contactors or from utility events are a real cause of unexplained board failures.
Unlike a voltage swell, which lasts cycles, a transient is a sub-cycle event. Both are part of the power quality picture an operator should monitor.
In Simple Terms
A transient, often called a voltage spike or surge, is a very short, sharp deviation from the normal waveform. IEEE 1159 splits transients into two…