Re: Filament Issue

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Jim Lux" <jimlux-at-earthlink-dot-net> 

 > Pure tungsten filaments are not damaged by running at low voltage and
 > in spite of their hellish power requirements it's not common to use them
 > where tubes are operate space-charge limited.

After all, we all have many pure tungsten filament things in our houses,
often on phase control dimmers to reduce the voltage substantially below
operating spec. Light Bulbs...

I suppose one could have some circuit where the low emission, and hence the
low current through the tube, would result in some sort of rise in the plate
voltage (shunt regulator, where the tube is normally almost all the way on?)
that might cause a flashover, but it would be pretty contrived...