How Selective Is Naval Eod

The transistor is a semiconductor electronic device that acts as amplifier, oscillator, switch, or rectifier. The term "transistor" is an English contraction of resistor transfer ("transfer resistance"). Currently they are found in virtually all artifacts everyday household: radios, televisions, tape recorders, audio and video players, microwave ovens, washing machines, automobiles, refrigeration equipment, alarms, quartz watches, computers, calculators, printers, fluorescent lamps, X-ray machines, scanners , ultrasound, mp3 players, cell phones, etc..

transistor types

Transistor contact tip

the first transistor was obtained gain invented in 1947 by J. Bardeen and W. Brattain. It consists of a germanium base on which they rest, close together, two metal spikes that form the emitter and collector. The emitter current is able to modulate the resistance "seen" in the collector, hence the name of "transfer resistor." It is based on surface effects, little known in his day. It is difficult to make (the points were adjusted by hand), fragile (one strike could move the ends) and noisy. But he lived with the junction transistor (W. Shockley, 1948) due to greater bandwidth. It has now disappeared.

binding Transistor bipolar

The bipolar junction transistor, or BJT for its acronym in English, is made primarily on a single crystal of germanium, silicon or gallium arsenide, which are qualities of semiconductors, conductive state between as metals and insulators such as diamond. On the glass substrate, are contaminated in a very controlled three zones, two of which are the same type, NPN or PNP, leaving two junctions formed NP.

N zone with elements donor of electrons (negative charges) and the P side to accept or "holes" (positive charges). Normally used as acceptors P elements to Indio (In), aluminum (Al) or gallium (Ga) and donors N to Arsenic (As) or phosphorus (P).

PN junction configuration, result in PNP or NPN transistor, where the middle letter always corresponds to the characteristic of the base, and two to the emitter and collector, while are the same type and opposite to the base, have different contamination between them (typically, the issuer is much more polluted than the collector).

The mechanism that represents the behavior semiconductor depend on such contamination, the associated geometry and the type of technology of pollution (gaseous diffusion, epitaxial, etc.) and the quantum behavior of the union.

Unijunction Transistor

also called junction field effect (JFET), was the first field effect transistor in practice. The material forms a bar-type silicon semiconductor N or P. At the end of the bar provides an ohmic contact, we have thus a field effect transistor type N of the form more basic. If P two regions are distributed in a bar of N material and connected externally to each other, there will be a door. One of these contacts will call another supplier and drain. Applying a positive voltage between the drain and the pump and connecting door to the supplier, establish a current, which call drain current with zero bias. With a potential negative gate voltage which we call a bottleneck, ceases conduction in the channel.

Field Effect Transistor

The field-effect transistor, or FET for its acronym in English, which controls the current versus voltage, have high input impedance.

field effect transistor junction, JFET, built by a PN junction.

Field Effect Transistor Insulated Gate, IGFET, in which the gate is insulated by a dielectric channel.

Field Effect Transistor MOS, MOSFET, which means MOS Metal-Oxide-Semiconductor, in this case the gate is metal and is semiconductor channel separated by an oxide layer.

Phototransistor

The phototransistors are sensitive to electromagnetic radiation at frequencies near that of light.