Path: utzoo!attcan!utgpu!news-server.csri.toronto.edu!rutgers!ub!kitty!larry
From: larry@kitty.UUCP (Larry Lippman)
Newsgroups: sci.electronics
Subject: Re: incandescent light bulb life extender
Summary: Report device failures & lamp appliance modifications
Message-ID: <4253@kitty.UUCP>
Date: 17 Dec 90 05:40:17 GMT
References: <4247@kitty.UUCP> <5297@rsiatl.Dixie.Com> <160@dalek.UUCP>
Organization: Recognition Research Corp., Clarence, NY
Lines: 47

In article <160@dalek.UUCP>, sjb@dalek.UUCP (Seth J. Bradley) writes:
> Just to add another data point, two of the diode buttons I tried
> also burned up (though 6 others worked fine for years).

	If people are experiencing failures where these lamp extender
buttons are burning up, then *please* report this to various appropriate
organizations - which are *not* aware of this being any serious problem!
I have listed telephone numbers and contact persons in my previous article.
Also, under the circumstances, I will disclose the name of the engineer I
spoke with at UL: Bruce Bohren.  

	Please bear in mind that for your report to be useful, you *must*
provide some vendor or manufacturer identification for the device that has
failed. 

> On one
> lamp I tried putting a 3 amp 400 PIV diode in series in the lamp's
> cord (this was a lamp which was on most of the time and which one
> of the buttons had burned up on).  I know that this would not be
> UL approved, but is it inherently unsafe?

	Lighting appliances which are "portable", i.e., which have a cord
and plug and not permanently attached to a structure, are generally exempt
from electrical inspection requirements.  The use of a non-UL approved
device in such an application is far less serious (from a regulatory and
insurance standpoint) than modification of permanently-wired lighting
fixtures as advocated by Mr. DeArmond.  This does not mean that modification
of a table lamp that voids UL approval is any less of a fire hazard, it
just means that it is probably not a local building code violation.

	The addition of a 2 amp fuse (say, wire lead type) to the 3 amp
400 PIV rectifier would make such a modification "reasonably safe".
Such components should be enclosed in flame-retardant insulating sleeving
(readily available), and installed so that: (1) the insulation will
permit heat dissipation of the forward voltage drop of the diode times the
RMS current under maximum load; (2) the fuse and diode will not be subject
to any mechanical wear and tear; and (3) the fuse and diode cannot come
in contact with any exposed metal portions of the lighting appliance.

	I do *NOT* recommend that you make the above modifcations, but
if you are bound and determined to do so, at least consider the above
guidelines.  I would suggest that instead you consider rough duty or
130 volt lamps.

Larry Lippman @ Recognition Research Corp.  "Have you hugged your cat today?"
VOICE: 716/688-1231   {boulder, rutgers, watmath}!ub!kitty!larry
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