Basics of Transistor,Faithful Amplification,Transistor Biasing & Stabilisation

In this slide presentation i tried to show the Basics of Transistor,Faithful Amplification,Transistor Biasing & Stabilisation

1. Welcome to our presentation আর হ্যা , অবশ্যই আইডি কার্ড সাথে নিয়ে আসবা৷     ✌ Electrical Device and Circuit

2. Transistor A transistor consists of two pn junctions formed by *sandwiching either p-type or n-type semiconductor between a pair of opposite types. Accordingly ; there are two types of transistors, namely; (i) n-p-n transistor (ii) p-n-p transistor

3. Some Facts about the Transistor The transistor has three regions, namely ; emitter, base and collector. The base is much thinner than the emitter while collector is wider than both. However, for the sake of convenience, it is customary to show emitter and collector to be of equal size . The emitter is heavily doped so that it can inject a large number of charge carriers (electrons or holes) into the base. The base is lightly doped and very thin ; it passes most of the emitter injected charge carriers to the collector. The collector is moderately doped.

4. Advantages N o cathode heater reducing power consumption, eliminating delay as tube heaters warm up, and immune from cathode poisoning   and depletion. V ery small size and weight, reducing equipment size. large numbers of extremely small transistors can be manufactured as a single integrated circuit.   L ow operating voltages compatible with batteries of only a few cells. C ircuits with greater energy efficiency are usually possible. For low-power applications in particular, energy consumption can be very much less than for tubes; C omplementary devices available, providing design flexibility including complementary-symmetry   circuits , not possible with vacuum tubes. V ery low sensitivity to mechanical shock and vibration, providing physical ruggedness and virtually eliminating shock-induced spurious signals. N ot susceptible to breakage of a glass envelope, leakage, outgassing, and other physical damage.

5. Faithful amplification The process of raising the strength of a weak signal without any change in its general shape is known as faithful amplification.

6. Conditions for faithful amplification Proper zero signal collector current Minimum proper base-emitter voltage (VBE) at any instant Minimum proper collector-emitter voltage (VCE) at any instant

7. Transistor biasing The proper flow of zero signal collector current and the maintenance of proper collector-emitter voltage during the passage of signal is known as transistor biasing . Biasing ensures base-emitter junction is properly forward biased and collector-base junction is properly reverse biased during the application of signal.

8. The process of making operating point independent of temperature changes or variations in transistor parameters is known as stabilisation . Stabilisation Why should we need stabilization??? Temperature dependence of I Individual variations Thermal runaway c

9. Methods of Transistor Biasing Base resistor method ( ii) Emitter bias method ( iii ) Biasing with collector-feedback resistor (iv ) Voltage-divider bias

10. Base Resistor Method Circuit analysis Stability factor Advantages Disadvantages

11. Voltage Divider Bias Method Circuit Analysis Stability Factor Advantages Disadvantages

12. The end