| | Transistor (Site not responding. Last check: ) |
 | | A bipolar transistor has base, emitter and collector electrodes, and is a current-controlled device (able to deliver a change in output voltage in response to a change in input current) with a low input impedance. |
 | | Point-contact transistors, though, were essentially laboratory curiousities -- they were hard to make (performance depended on the exact placement of the wires on the germanium), and none too reliable (since they responded nearly as much to their surroundings as to their input signals). |
 | | In the bipolar transistor (as in all modern transistors), the vital junctions between the N-type and P-type layers are buried deep within the semiconductor crystal where they cannot be affected by their surroundings. |
| encyclobeamia.solarbotics.net /articles/transistor.html (684 words) |