What is Transistor?
[[File:Transistors.agr.jpg|thumb|A few types of individually packaged transistors]] A '''transistor''' is an [[electronic component]] that can be used as part of an [[amplifier]], or as a [[switch]].<ref>{{cite web |url=http://hyperphysics.phy-astr.gsu.edu/hbase/solids/trans.html |title= The Junction Transistor |date=1999 |access-date= 2012-05-07}}</ref> It is made of a [[semiconductor]] material. Transistors are found in most [[electronics|electronic devices]]. The transistor was a major advancement after the [[triode]] tube, with using much less electricity, and lasting many years longer, to switch or amplify another electronic current. The transistor can be used for a variety of different things including amplifiers and digital switches for computer [[microprocessor]]s. Digital work mostly uses [[MOSFET]]s. Some transistors are individually packaged, mainly in order to handle high power. Most transistors are inside [[integrated circuit]]s. == How they work == [[File:Transistor basic flow.svg|thumb|When the center pin is powered, the power can flow.]] Transistors have three terminals: the gate, the drain, and the source <ref>{{cite web |url=http://mysite.du.edu/~etuttle/electron/elect2.htm |title=transisting |author= Calavert, J.B. |date=4 May 2002 |access-date=7 May 2012}}</ref> (on a bipolar transistor, the wires can be called the emitter, the collector, and the base). When the source (or emitter) is connected to the negative terminal of the battery, and the drain (or collector) to the positive terminal, no electricity will flow in the circuit (if you have only a lamp in [[series circuit|series]] with the transistor). But when power flows through the gate (or base), the transistor will allow electricity through. This is because when the gate is positively charged, the positive electrons will push other positive electrons in the transistor letting the [[electron flow|negative]] electrons flow through. The transistor can also work when the gate is just positively charged, so it doesn't need to be touching th