How do transistors amplify signals?

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In summary, transistors amplify by using a small input current to control a larger current at the output. Efficiency is measured by the output power divided by the total input power from the power supply, which is always less than one.
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d logician
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i have no idea how transistors amplify ...how can the output gain be greater than the input gain ? ...efficiency is output/input which can never be greater than one, right?
 
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sorry how can output be greater than input ...not output gain greater than input gain
 
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Do you understand how a relay works? It uses low voltage and low current to switch a higher voltage and higher current. Transistors are similar.

In the case of transistors, a small input current controls the amount of current drawn from a power supply to create a much larger replica of itself at the output. Efficiency in the case of amplifiers is not the output signal divided by the input signal but the output power divided by the total input power from the power supply. The power supply always supplies more power than is available at the output so the efficiency is still always less than one.
 

1. How do transistors amplify electrical signals?

Transistors amplify electrical signals through a process called "transistor action." This is achieved by using the transistor's three layers of doped material, which create two PN junctions. By applying a small voltage to the base layer, the transistor allows a larger current to flow from the collector to the emitter, effectively amplifying the electrical signal.

2. What makes transistors a better option for amplification compared to vacuum tubes?

Transistors are smaller, more efficient, and more reliable than vacuum tubes. They also require less power to operate and produce less heat. Additionally, transistors can be easily miniaturized, making them suitable for use in electronic devices such as computers and smartphones.

3. What are the two types of transistor amplifiers?

The two types of transistor amplifiers are bipolar junction transistors (BJTs) and field-effect transistors (FETs). BJTs use both electrons and holes as charge carriers, while FETs use only one type of carrier, either electrons or holes.

4. How does a transistor amplify both AC and DC signals?

Transistors amplify both AC and DC signals by using a biasing voltage. This voltage is applied to the base terminal, and it determines the operating point of the transistor. The biasing voltage allows the transistor to amplify both positive and negative portions of the input signal, resulting in amplification of both AC and DC components.

5. Can transistors amplify signals without introducing distortion?

No, transistors, like all electronic components, introduce some level of distortion to the amplified signal. This distortion is caused by non-linearities in the transistor's characteristics. However, with proper design and use of feedback, the distortion can be minimized to a negligible level.

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