A transient voltage suppressor or TVS is a general classification of an array of devices that are designed to react to sudden or momentary over-voltage conditions. One such common device used for this purpose is known as the transient voltage suppression diode designed to protect electronic devices against over-voltage. Another design alternative applies a family of products that are known as metal-oxide varistors (MOV) that protect electronic circuits and electrical equipment. Voltage suppressors act a circuit breakers. Voltage suppressors can also be non integrated electronic noise suppressors.