electro-Physics: 17.3409 volts

From: Dwight K. Elvey <dwight.elvey_at_amd.com>
Date: Mon Dec 13 17:55:12 2004

>From: "Tom Jennings" <tomj_at_wps.com>
>
>On Mon, 13 Dec 2004, Carlos Murillo wrote:
>
>> > It isn't much good for home use. In fact, lamps don't
>> > do as well on DC as AC because of the electrical effects
>> > of the wire evaporating ( not sure which end goes first ).
>>
>> Ah, the "Edison Effect".
>
>I'd heard of the effect, but not for a long time, and probably paid little
>attention to it :-)
>
>So, how pronounced is this DC-filament effect? If I collect
>dead lightbulbs from my cars, should I see filaments with gaps
>burned towards the ground end more often than not?
>
>(Tapered filaments would fix this.)
>
>

Hi
 I would think the effect is smaller today since we don't
still use high vacuum bulbs. Most have a partial atmosphere
of an inert gas. The Edison effect is the same as used
in vacuum tubes. You still might see a slight bias towards
one or the other end.
 You have to realize that work hardening and fracturing
of the filament in an auto is a large factor in shortening
the life of these lamps.
Dwight
Received on Mon Dec 13 2004 - 17:55:12 GMT