For many years, some Manufacturers have incorporated discrete devices into their circuit and board designs in an attempt to mitigate the effects of electrical power disturbances of various kinds. Some of those devices include:
- Zener diodes – A semi-conductor that becomes conductive and begins to act like shunt resistor when circuit voltage approaches a design threshold. Zener diodes are often applied at a value around twice the nominal circuit operating voltage. They typically fail when operated above their design current, which can be quite small or quite large. They may fail open or shorted.