Test questions

1. How does a field effect transistor provide the relay rule?

2. How is it possible to control the current flowing through a FET with a controlled p-n-junction?

3. Why does the inversion of conduction happen in MOS transistors?

4. Under what condition do MOS transistors operate in the enriched and depleted modes?

5. Draw the CVC of all type FET’s.

6. What kind of processes form the flat portion of FET’s output characteristics?

7. Compare FET’s and BT’s. What are the advantages and disadvantages of FET’s?

CHAPTER 6. Semiconductor Thyristors

Thyristorsare used as high-power controlled switches to switch currents of both DC and AC circuits. Thyristors have inner positive feedback as distinct from transistors.

With reference to their action, thyristors are divided into the following main types: diode thyristors, triode thyristors, turn-off thyristors, silicon symmetrical thyristors, and photo- thyristors.