[GreenKeys] [External] Tip on loops

[Jones, Douglas W]

On Oct 4, 2019, at 2:28 PM, Jim Haynes wrote:

> ... The reason for this is the temperature
> coefficient of resistance in the metal filament.  As current increases
> the filament gets hotter, increasing its resistance and tending to
> reduce the current.

I vaguely recall some interesting circuits that I recall seeing in the 1960s that used incandescent bulbs as active elements, exploiting both the non-constant resistance of the bulb and the thermal time-constant of the filament.

		Doug Jones
		jones at cs.uiowa.edu