[GreenKeys] [External] Tip on loops

[Dave Horsfall]

On Fri, 4 Oct 2019, Jones, Douglas W wrote:

> 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.

Wein oscillators?  Hardly seen these days, but the light bulb was really 
important.

-- Dave