Explain with the characteristics the effect of gate current on break over voltage of SCR.

Ans:

Effect of gate current on break over voltage of SCR:

 

Explanation: 

• The voltage at which the SCR comes into conduction without any gate current (Ig=0) is called break over voltage VBO.  

•  By the application of minimum required gate current (Ig1), SCR can be turned on before the break over voltage.  

•  If we increase the gate current (Ig2) with in the specified limits SCR can be turned ON at a voltage much lesser than the break over voltage.  

•  So by increasing the gate current (Ig2>Ig1>Ig0) we can turn on the SCR at smaller voltages.  

•  Once SCR is latched to ON state, gate loses its control unless and until current through SCR is not reduced below holding current or voltage across SCR is reversed, SCR will keep conducting.