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Consider the following statements: 1. In a silicon controlled rectifier (SCR), if the cathode gate is reverse-biased, then the SCR cannot fire at all. 2. The turn-on time of an SCR increases with temperature. 3. After an SCR is turned on, it can be made to turn off again by reverse biasing the gate. 4. Gate recovery time is the minimum time that the anode voltage must be maintained below holding voltage VH to turn off the SCR. Which of these statements are correct?

Consider the following statements: 1. In a silicon controlled rectifier (SCR), if the cathode gate is reverse-biased, then the SCR cannot fire at all. 2. The turn-on time of an SCR increases with temperature. 3. After an SCR is turned on, it can be made to turn off again by reverse biasing the gate. 4. Gate recovery time is the minimum time that the anode voltage must be maintained below holding voltage VH to turn off the SCR. Which of these statements are correct? Correct Answer 1 and 2 only

SCR:

  • SCR is a three junction device
  • J1, J3 is forward bias

  • J2 is reverse bias.

 

Important Points

SCR can be turned OFF by

i) Reducing the anode current below the holding current (IH)

ii) By reverse biasing it → force commutation.

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