Over Voltage Protection Using Crowbar Devices for Low Voltage Loads

Abstract

All electronics and electrical instruments can be damaged mainly by voltage transient. This paper present s the development of over voltage protection circuits using crowbar devices such as SCR and TRIAC. Using the gate triggering a silicon controlled rectifier (SCR) and TRIAC is made to turn ON which protects the load from damage caused by overvoltage. With the help of transistor amplifier by amplifying the excess output voltage of the regulator the gating signal is generated. In actual practice when regulators gets shorted such a condition arises. To check this type of condition the resistance connected between input and output of the regulator is changed to produce the excess voltage. The sensitivity of the over voltage protection circuit is discussed.