A device that accepts a low-power signal and outputs a high-power signal that matches the waveform of the input. Typically operating in the analog domain, amplifiers are available to boost electrical and optical signals. The heart of an amplifier is the transistor (see below). See amplifier classes
, Class D amplifier
Just a Transistor
Watch the Flow
An amplifier enables a low current to modulate a high current. Based on the amount of electrons (e) reaching the gate, the depletion region increases or decreases causing high-power at the source to fluctuate. In a real transistor, there are trillions of flowing electrons. See transistor
Notice how the "depletion region" reacts to more voltage at the gate. This example can be analog (variable voltage) or digital (quick on and off).