The junction gate field-effect transistor (JFET or JUGFET)'s the simplest type of field effect transistor. It can be used as an electronically-controlled switch or as a voltage-controlled resistance. Electric charge flows through a semiconducting channel between "source" and "drain" terminals. By applying a bias voltage to a "gate" terminal, the channel's "pinched", so that the electric current's impeded or switched off completely. Structure The JFET's a long channel of semiconductor material,… (More on Jfet)