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From: karn@envy.bellcore.com (Phil R. Karn)
Newsgroups: sci.electronics,misc.consumers
Subject: Re: Halogen Lamps, too (was Re: florescent bulbs replacing inca
Message-ID: <1990Nov26.213831@envy.bellcore.com>
Date: 27 Nov 90 02:38:31 GMT
References: <1990Nov16.091211@mathcs.emory.edu> <1990Nov17.211808.21546@ameristar> <27836@mimsy.umd.edu> <57@deeptht.UUCP> <36224@cup.portal.com> <4171@media-lab.MEDIA.MIT.EDU>
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In article <4171@media-lab.MEDIA.MIT.EDU>,
minsky@media-lab.MEDIA.MIT.EDU (Marvin Minsky) writes:
|> IN two other rooms, I used similar units made by Lights of America.
|> These are half the cost (9-10 dollars).  But the solid state
|> converter-ballast unit in the base burns out, and most of them have
|> died in less than 2000 hours.  (The Panasonic units contain a
|> fair-sized inductor, while the LOA units contain a mere couple grams
|> of transistors and other small components.  Obviously the margins
are
|> too small.)

I have taken these LOA flourescents apart and traced the circuit
diagram.  While doing this I noticed some pretty shoddy soldering on
the PC card.  Leads were too long and too much solder was used. In the
bulb I examined I found a solder bridge right across the DC supply
rails, although it didn't short because it didn't break through the
solder mask.

Despite this, all of the 10 or so bulbs I've bought have worked fine
so far. If one fails I will be sure to do a post-mortem.

Phil