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From: pmk@prometheus.UUCP (Paul M Koloc)
Newsgroups: net.consumers,net.sci
Subject: Re: lightbulbs
Message-ID: <238@prometheus.UUCP>
Date: Thu, 22-May-86 18:53:08 EDT
Article-I.D.: promethe.238
Posted: Thu May 22 18:53:08 1986
Date-Received: Sun, 25-May-86 11:56:34 EDT
References: <446@hropus.UUCP> <5436@alice.uUCp> <1039@kitty.UUCP> <2214@cae780.UUCP>
Reply-To: pmk@prometheus.UUCP (Paul M Koloc)
Organization: Prometheus II, Ltd., College Park, MD 20740-0222
Lines: 30
Xref: watmath net.consumers:5337 net.sci:929

In article <2214@cae780.UUCP> gordon@cae780.UUCP (Brian Gordon) writes:
>In article <1039@kitty.UUCP> larry@kitty.UUCP (Larry Lippman) writes:
>>Standard lightbulbs are available in a 130 volt rating . Operating
>>a 130 volt lamp at 120 volts does not appreciably lower the light output, 
>>but seems to appreciably increase lamp life (as compared to 120 volt lamps).
>> .. as "rough service" lamps, [ I ] had much better luck with the 130 volt
>>variety for outdoor use.  	...
>
>I heartily second the 130v suggestion.  The "rough service" bulbs are very
>useful too, they survive ... .vibration and rough handling which usually 
>kill the bulbs long before they can burn out.  >

Operating the lamps at lower temperatures prevents "excessive 
embrittlement and evaporation (burn-out)".  But the lower the 
temperature the less the light output and luminous efficiency.
Since AC current drives the lamps in such a way that the temperature 
spikes at 120 times per second during 60 hertz operation it would be
better to operate them at a very much higher frequency or by 
regulated DC.  Direct current desk lamps were a kind of fad a 
five or six years ago, but they were over driven and used small 
auto "tail-light" bulbs.  It would seem to me a compact and 
EFFICIENT Direct Current device could be made to drive even 120 
volt variety bulbs with MORE radiant efficiency and cooler peak 
and maybe even average temperatures. 

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| Paul M. Koloc, President: (301) 445-1075                | FUSION |
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