From: utzoo!decvax!harpo!ihnp4!ixn5c!inuxc!pur-ee!kk9w
Newsgroups: net.invest
Title: Re: bulb savers
Article-I.D.: pur-ee.707
Posted: Mon Dec  6 09:37:42 1982
Received: Tue Dec  7 02:12:44 1982
References: teklabs.1575



The problem with DC lamps is that the filaments are subject to a process
called DC notching.  This is a result of the molecules of the filament being
pulled along with the DC current, causing thin places or notches in the
filament.  Naturally, this process will eventually break the filament if
it is allowed to progress, hence the preference for ac lights or two positions
on the DC lamp power supply.

Dave Andersen pur-ee!kk9w