3: emitter, base, collector
There are three regions but to be absolutely picky I think only two of them need be doped.
Nope: they MUST be doped NPN or PNP. If any are undoped it will not function as a transistor.
A transistor typically has three regions: the emitter, the base, and the collector. In a bipolar junction transistor (BJT), these regions are crucial for its operation, with the emitter injecting charge carriers, the base controlling their flow, and the collector collecting them. In a field-effect transistor (FET), the three regions consist of the source, gate, and drain. Each region plays a vital role in the transistor's functionality and performance.
Transistor transistor logic is one type of many different types of bipolar transistor based digital logic circuitry. It is very efficiently implemented in integrated circuit chips, needs only one power supply voltage, and operates at reasonably high speeds. Transistor transistor logic was first developed in the middle 1960s as a modification of the diode transistor logic, then in use in some digital logic integrated circuit chips but dating back to the earliest discrete bipolar transistor logic developed in the late 1950s and derived from vacuum tube point contact diode logic used in many early first generation computers. Transistor transistor logic integrated circuits dominated the computer and electronic digital controller market from the late 1960s until the middle 1980s, when metal oxide semiconductor field effect transistor based microprocessors and microcontrollers began to replace it. By the early 1990s transistor transistor logic and other bipolar transistor based digital logic integrated circuits had been replaced with equivalent complementary metal oxide semiconductor field effect transistor integrated circuits that were both faster and consumed less power (thus running much cooler) or with programmable logic devices of various types. In general transistor transistor logic is now considered obsolete.
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Two, either in NPN or PNP transistors
A transistor typically has three regions: the emitter, the base, and the collector. In a bipolar junction transistor (BJT), these regions are crucial for its operation, with the emitter injecting charge carriers, the base controlling their flow, and the collector collecting them. In a field-effect transistor (FET), the three regions consist of the source, gate, and drain. Each region plays a vital role in the transistor's functionality and performance.
Transistor transistor logic is one type of many different types of bipolar transistor based digital logic circuitry. It is very efficiently implemented in integrated circuit chips, needs only one power supply voltage, and operates at reasonably high speeds. Transistor transistor logic was first developed in the middle 1960s as a modification of the diode transistor logic, then in use in some digital logic integrated circuit chips but dating back to the earliest discrete bipolar transistor logic developed in the late 1950s and derived from vacuum tube point contact diode logic used in many early first generation computers. Transistor transistor logic integrated circuits dominated the computer and electronic digital controller market from the late 1960s until the middle 1980s, when metal oxide semiconductor field effect transistor based microprocessors and microcontrollers began to replace it. By the early 1990s transistor transistor logic and other bipolar transistor based digital logic integrated circuits had been replaced with equivalent complementary metal oxide semiconductor field effect transistor integrated circuits that were both faster and consumed less power (thus running much cooler) or with programmable logic devices of various types. In general transistor transistor logic is now considered obsolete.
transistor current is dependent on a factor known as Beta of the transistor. a darlington pair has a large Beta(10,000) , a small signal transistor such as the 2n3904 has a small beta of around 100. the beta of a transistor determines the amount of current that flows from collector to emitter ( bipolar transistors) for each amount of current that flows into the base you get a hundred fold increase between collector and emitter (2n3904), so you insert 1 ma (milliamp) into the base, you get 100 ma out the emitter. there is a doped region in the middle of the transistor that expands when current is applied to the base, this expansion allows more current to flow from collector to emitter (npn). there are many types of transistors but they all employ basically the same function. The mathematics involved is a bit more complicated but I speaking in general terms here to avoid getting someone lost.
In an NPN transistor an emiter follower refers to an amplifier topology. The emiter follower configuration is when the emitter of a N-Type Bipolar Junction Transistor (BJT) is connected to the common point on a circuit (typically ground). This is not always the case, however, because many amplifier configuration exist.
The two basic types of transistors are the NPN transistorand the PNP transistor. Certainly there are many other semiconductor devices, but these are arguably the two basic ones.
There are many different part-numbers found on transistors. These part numbers are to distinuguish individual models for voltage-ratings etc., but there are only two different transistor types; PNP (Positive Negative Posistive), and NPN (Negative Positive Negative)
A bipolar neuron typically has one axon and one dendrite. This structure allows it to transmit signals efficiently between two distinct regions, such as sensory receptors and the central nervous system. Bipolar neurons are commonly found in sensory pathways, including the retina of the eye and the olfactory system.
germanium - bipolar/darlington?/npn/pnp =4 silicon - bipolar/darlington/thickfilm/thinfilm/npn/pnp =8 J-FET/enhancement/depletion/nchannel/pchannel = 4 MOSFET/enhancement/depletion/nchannel/pchannel = 4 I know of 20 kinds without considering application packaging & frequency (speed).
We use chips of silicon in computers and mobile phones and many other devices because we can control the conductivity of silicon. We cannot control the conductivity of metal conductors -- they are always highly conductive. The really magical thing about silicon is that it can be doped such that a few regions (the "transistor channels") can be actively switched from conductive to insulating, millions of times per second. I wouldn't say I prefer one over the other, though -- all those devices invariably *also* have many metal conductors.
yes it is possible. Bipolar is very difficult to diagnose, especially in teens. Bipolar has similar aspects as ocd. infact Bipolar has many other traits similar to many,many other disorders, that's why it is so hard to diagnose. But yes it is possible. hope this helps
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