Why transistors are used

Here we list the applications of transistors. Transistors are used in digital and analog circuits as a switch. Cellular phones would be one of the most widely used applications of transistors. Every cell phone uses a transistor amplifier. Transistors are used in building some of the integrated circuits IC. Transistors are used in almost every electronics devices from stoves to computers and pacemakers to aircraft.

After knowing some brief everyday uses of transistors , We take look into some important transistor applications in details :. In most of the applications, transistors are used as a switch in circuits. If the electronic circuit uses the transistor as a switch, then the biasing of the transistor either use PNP transistor or an NPN transistor that we must have to see.

A transistor basically operated in three different modes,. The other two operating regions of transistor Saturation Region and the Cut-off Region were used to operate a transistor switch. Transistor is operated as a switch in only this two operating regions. When we apply the voltage at the base terminal of a transistor then switching operation is performed.

So that, the transistor acts as a short circuit and we can say transistor is in OFF condition. The collector current flows through the transistor. In that case, switching connection load here LED lamp is connected to the output side with a reference point. Transistor circuits are used as an amplifier circuit. In a previous article, we discuss in detail about the transistor amplifier circuit and how the transistor amplifier works?. If you did not read that recommended to read — Transistor circuit as an amplifer.

In earlier, vacuum tubes are used for the same applications but after the invention of the transistor, transistor take place in almost all small power electronics applications.

Because of the transistor, the size of IC reduced. Transistor has following brief advantages for uses in some practical applications :. Read also — Applications of semiconductor. The transistor is the basic semiconductor device which uses for regulating the current and voltage in small electronics circuits.

Transistors are used in many amplifying circuits for amplifying weak signals. Now a days, They are used in almost every electronics devices. Cell phones contain a transistor circuit as a sound amplification circuit. Transistors are so small in size so that the size of modern IC reduced and we got benefited. The base is responsible for activating the transistor. The emitter is the negative lead while Collector is the positive lead. Uses of Transistor.

Amplifier Circuit. A transistor can be used to amplify current. Vbe biasing voltage produced in the base-emitter junction Due to the forward biasing of the base-emitter junction, the electrons start flowing from emitter to recombine with holes in the base, the base becomes negatively charged.

If the base current Ib is increased by a small amount, hole-electron recombination will get neutralized, the collector current Ic will be increased.

Therefore, a small change in current Ib in the base circuit would control a large amount of Ic current. Example of Microphone. The microphone is a transducer that converts our voice or sound wave to an electronic signal.

The electrical output of the microphone varies according to the sound waves as the base current Ib is varying because of the small alternating voltage produced by the microphone which means a small change in Ib can cause a large change in Ic.

When this output of the microphone is given to the transistor as an input. The varying collector current Ic flows into the loudspeaker, and we know that if there are changes in the input of the transistor there will be a large change in the output of the transistor.

Thus, the transistor amplifies the electronic signal of the microphone. The frequency remains constant but the amplitude of the sound wave from the loudspeaker is higher than sound waves fed into the microphone. Oscillator Circuit. An electronic oscillator is a device that generates continuous electrical oscillations.

In a simple oscillator circuit, a parallel LC circuit is used as a resonant circuit and an amplifier is used to feed energy to the resonant circuit.

The frequency gets resonantly amplified, and the output acts as a source of an alternating voltage of that frequency. The frequency can be varied by varying L or C. Transistor Used as a Switch.

The switched controlled current goes between emitter and collector, and the controlling current goes between emitter and base. The transistor as a switch used in making:. Memory cards in mobile phones. Most of the parts of modern electronic devices like smartphones, smartwatches, etc are all made up with transistors where they act as switches. Logic gates, flip-flops circuit.

Microprocessors and Microcontrollers. Register circuits.