Characteristics of SCR

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Aim:-

To obtain the V-I characteristics of SCR and find the break over voltage holding current.


Apparatus: -

Ammeter, resistor, Voltammeter, breadboard, wires, SCR.












Theory: -

 A silicon controlled rectifier (SCR) is a semiconductor device that acts as a true electronic switch. It can change the alternating current into a direct current. It can control the amount of power fed to the load. Thus the SCR combines the feature of the rectifier and a transistor. If the supply voltage is less than the break over-voltage, the gate will open. Then increase the supply voltage from zero, a point is reached when the SCR starts conducting. Under this condition, the voltage across the SCR suddenly drops and most of the supply voltage appears across the load resistance RL. If proper gate current is made to flow the SCR can close at a much smaller supply voltage.


VAK = _______

Trigger count =IG=_______________



 
Procedure:-

1)   Set the V

Now increase IG in microampere at regular intervals. At a particular value of IG (around 10 to 50 microampere current IAK will drop to a low value so change the voltmeter range to 2V.

2)   Now as V

3)   Repeat

4)   Draw a graph keeping V

  

 

VAK = _______

Trigger count =IG=_______________


Result:-

Studied the characteristics of SCR in forward bias break over takes place at V= ___Volts



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