Re: [Phys-l] three-way bulb

["Larry Woolf" <larry.woolf@ga.com>]

The 50 and 100 W filaments are in parallel so there is 110V across each
of the filaments.  If we lived in a constant current world, then the
filaments would be arranged in series.

For details about light bulb dissection:
<http://www.sci-ed-ga.org/modules/materialscience/light/pdf/section_11.p
df>

Larry Woolf
General Atomics
www.ga.com
www.sci-ed-ga.org
 

-----Original Message-----
From: phys-l-bounces@carnot.physics.buffalo.edu
[mailto:phys-l-bounces@carnot.physics.buffalo.edu] On Behalf Of Bernard
Cleyet
Sent: Wednesday, April 05, 2006 8:02 AM
To: Forum for Physics Educators
Subject: Re: [Phys-l] three-way bulb

"... or in series with each other"

You mean parallel, don't you?  The one's I have (and no longer use) are
labeled 30, 70, 100; 50, 100, 150; 100, 200, 300 [mogul base], etc.
AL, I suspect, is not an experimentalist; otherwise he'da taken one
apart.  Often one may carefully prise the base off w/o breaking the bulb
using a thin screwdriver or knife.  Better an old one using soldered (Cu
not Al) base.  Otherwise cut the screw connection and scrape away the
bottom of the base connections.  If this fails, break the bulb and
observe.  Do it soon; it's a dying technology.

Herb Gottlieb wrote:

> The base of the bulb is divided into three parts which connect
> to three terminals in the 3-way bulb socket. Rotating the switch 
> of the 3-way socket connects either the 50W or 100W bulb filaments
> separately, or in series with each other