Can u explain the main function of the three parts of transistor?

Question

the main parts are :- emitter, base collector

Answer 1

An NPN transistor can be considered as two diodes with a shared anode region. In typical operation, the emitter–base junction is forward biased and the base–collector junction is reverse biased. In an NPN transistor, for example, when a positive voltage is applied to the base–emitter junction, the equilibrium between thermally generated carriers and the repelling electric field of the depletion region becomes unbalanced, allowing thermally excited electrons to inject into the base region. These electrons wander (or "diffuse") through the base from the region of high concentration near the emitter towards the region of low concentration near the collector. The electrons in the base are called minority carriers because the base is doped p-type which would make holes the majority carrier in the base.
The base region of the transistor must be made thin, so that carriers can diffuse across it in much less time than the semiconductor's minority carrier lifetime, to minimize the percentage of carriers that recombine before reaching the collector–base junction. The thickness of the base should be less than the diffusion length of the electrons. The collector–base junction is reverse-biased, so little electron injection occurs from the collector to the base, but electrons that diffuse through the base towards the collector are swept into the collector by the electric field in the depletion region of the collector–base junction.
Voltage, current, and charge control
The collector–emitter current can be viewed as being controlled by the base–emitter current (current control), or by the base–emitter voltage (voltage control). These views are related by the current–voltage relation of the base–emitter junction, which is just the usual exponential current–voltage curve of a p-n junction (diode).
The physical explanation for collector current is the amount of minority-carrier charge in the base region. Detailed models of transistor action, such as the Gummel–Poon model, account for this charge explicitly to explain transistor behavior more exactly. The charge-control view easily handles photo-transistors, where minority carriers in the base region are created by the absorption of photons, and handles the dynamics of turn-off, or recovery time, which depends on charge in the base region recombining. However, since base charge is not a signal that is visible at the terminals, the current- and voltage-control views are usually used in circuit design and analysis.
In linear circuit design, the current-control view is often preferred, since it is approximately linear. That is, the collector current is approximately 'beta' times the base current. The voltage-control model requires an exponential function to be taken into account.

Answer 2

By themselves, they really don't have any 'function' as such. Everything about transistor action happens as a result of the emitter-base and collector-base junctions being physically close enough that they can interact.

Normally, the emitter-base junction is forward biased and the collector base is reverse biased. Since the emitter-base junction is forward biased, majority carriers from the emitter region cross the junction (becoming minority carriers inthe base region) where they are join with majority carriers in the base region to cause forward current to flow in the external base-emitter circuit.

But since the base region is very thin and the minority carriers from the emitter are within the 'depletion zone' of the reverse-biased collector-base junction, they will also be swept across the reverse-biased junction and appear as current in the external collector-emitter circuit.

If the ratio of the carriers in the collector to the carriers in the base is quite large then, as the base current varies, the collector current varies as some multiple of that and current amplification (transistor action) happens.

HTH ☺

Doug

Answer 3

individually, each part has no main function. it's when you use them in conjunction with one another that you get the amplification process. now for an example lets use a simple BJT, say 2N3904 is a NPN transistor. now to better understand picture a diode between the base and the emitter where the anode is at the base and cathode at the emitter. bias the collector at +5V and put the emitter at zero for reference (ground). now lets say you apply 3V to the base, it's going to kick on that "diode" between the base and the emitter and your going to get current to start coming from ground into the emitter. when that current hits the base its just going to keep going (such a small amount is lost through the base that we can ignore it, i'm talkin micro-amp range) the current just goes up through the collector and to your load. now this is an extremely basic example, you'll have to do much more in depth studies to fully under stand how it works. hope that helps you better grasp the concept. as with all electronics use caution because current can be lethal!

Answer 4

I would normally but I`m too drunk to explain that the base is the amplifier part , you have a positive to negative from the emmittter to collector which is a constant, but if you introduce a signal to the base then that amplifies the whole thing and wotsit doda , haha and can be used as a switch and is the basis of all transistor chips, read up on binary gates and you`ll get the inea

Answer 5

Spirt of a man can be strong but the body is weak. Luckily by the mercy and grace of God our souls can be saved even if our spirit goes down and body gives in to sin. Paul often teaches that the body is often the instrument of sin. ( 1 Cor 6:18 ) and the body must die as a penalty for sin ( Rom 7:27 ) and sin dishonors dishonors person's body ( Rom 1:24 ). On the other hand , believers in God Christ may " put to death the deeds of the body" ( Rom 8:13 ) and present their bodies as the holy sacrifices that please God ( Rom 12:1 ) Since human life requires a body, somemes the term "body" symbolizes the whole person. Paul's prayer for the Thessalonians is that they may be sanctified in all aspects of their life; spirit, soul and body. Every part of a Christian life should bear evidence that he or she is set apart as holy to God. This will result in being blameless at the coming of our Lord God Jesus Christ. We who are Christians are already saints in the sense that we have been set apart to God. Paul exhorts the Thessalonians to express holiness in this life so that the Lord would approve of their conduct upon His return. Blameless does not mean sinless, but free form causes for reproach and regret. By using spirit and soul, Paul was not indicating that the immaterial part of man could be divided into two substances. About Soul: The Bible has two distinct meanings for this word. 1. That which makes a human or animal body alive. This usage of the the word "soul" refers to life in the physical body. ( For example, in Gen 35:18 the soul of a dying person departed at death. ) 2. The word soul also refers to the inner life of a person, the seat of emotions( the soul is described as the seat of many emotions and desires: for food ( Deut 12:20-21), for love ( Songs 1:7), longing for God ( Ps. 63:1 ), rejoicing ( Ps 86:4 ), knowing ( Ps 139:14), and memory ( Lam 3:20 ), and the center of human personality. Spirit is a word with three distinct meanings in the Bible. 1. The word is used as a general reference in the NT to the spirit of human beings ( Matt 5:3, Rom 8:16, Heb 4:12 ) 2. The second usage of the word spirit is in the reference to good and evil spirits, meaning beings other than God and humans. Good spirit =Angel ( Ps 1 104:4 ), evil spirits ( Mark 9:25, Acts 19: Rev 18:2 ) 3. The word spirit also refers to the Spirit of God, the Holy Spirit