🚀 go-pugleaf

In article <1992Aug4.051826.10582@u.washington.edu>, whit@milton.u.washington.edu (John Whitmore) writes:
|>In article <13404@creare.COM> kwg@creare.UUCP (Kent Goeking) writes:
|>
|>>   I would like to know if there are any materials that demonstrate negative
|>>   resistance on the macroscopic scale.  I am aware of this behavior in tunnel
|>>   diodes but I wonder if it might not occur in other structures. 
|>
|>	The classic example is a neon lamp; resistance is high until
|>one reaches the breakover voltage, then it drops (because the gas
|>becomes ionized).  Some semiconductors have similar properties,
|>when they are undoped, because avalanche conduction makes new
|>charge carriers (and lowers the resistance).  
|>
|>	John Whitmore
|>
|>p.s. negative resistance is also  possible in some AC circuits, if
|>the right kinds of tricks are played... this is a kind of trick
|>for analyzing oscillator circuits.
|>

	Another classic example is the 'silicon controlled
	rectifier' which is actually a pnpn transistor.

	- Anis.