[aprssig] TAPR Dayton Solar Talk

Tue May 31 07:44:31 EDT 2011


About 2 years ago, as an experiment I replaced a bulb in a lamp which with a
timer is used to make the house look occupied.  It runs about 10 hours a
day, and had a high failure rate even with premium bulbs.  It has worked
flawlessly with the CFL since then.

I also replaced the 4 bulbs in my bathroom, over the sink.  That lasted
about 3 days due to RF noise.  I listen to a local AM station while shaving,
and it was difficult to pay attention due to the level of noise.  Those
bulbs have been relocated to the guest bathroom.  I also tested them in the
shack, with the same result on HF.  All were Westinghouse, but the Ecosmart
bulbs borrowed from my Green neighbor tested the same.  Perhaps a bad run,
but like you, I have purchased a "lifetime" supply of standard incandescent,
mostly commercial 130 volt units.  The LED units look more promising, and I
will certainly give some a try when the price falls.  



-----Original Message-----
From: aprssig-bounces at tapr.org [mailto:aprssig-bounces at tapr.org] On Behalf
Of Jim Sanford
Sent: Monday, May 30, 2011 9:19 PM
To: TAPR APRS Mailing List
Subject: Re: [aprssig] TAPR Dayton Solar Talk


I, too have suffered the premature failures.  So many, that on top of the
onerous mercury disposal rules, I'm over CFLs -- bought a lifetime supply of
incandescents while I could, and slowly converting to LEDs   Adding insult
to injury, the CFLs are very RF noisy -- so noisy, that my X-10 remote
controls can turn one on, but never off, not matter how much filtering I put
in upstream of the noise generator.

IEEE Spectrum recently ran an article about a teardown, which explains why
the CFL's fail prematurely -- to keep manufacturing costs down in China, the
electronics in the base are hand soldered (badly, to be kind, the pictured
solder joints were terrible!).  So, when the get hot, solder joint fails . .
. and another few grams of mercury head to the land fill, err. recycling

Also confirmed in a separate IEE article what I had long suspected -- LEDs
are expensive because of the thermal managment issues -- 15 watts dissipated
over a few square cm is a LOT of BTU/hr-ft-squared!  Still, volume
appriaching the point where prices will drop, then like all things
semiconductor, the price drop will be precipitous.  Until then,
incandescents here we come . . .. 

Spectrum tends to shill for all things "green", so I'm a bit skeptical of
their predictions.  Still, their data and my own experience suggests that
the LED price will come down, only question is how soon and how fast.

Good luck to all,
wb4gcs at amsat.org

On 5/30/2011 9:18 PM, Bob Bruninga wrote: 

	Interesting.  About 1/3rd of mine are mounted upside down in ceiling
fixtures, and I have not noticed any failures...
	Bob, WB4APR
	---- Original message ----

		   The only way one can get the many thousand hour life from
a CFL is to
		mount them base down. When the base is up the heat from the
bulb rises into
		the power supply in the base and is what kills them.
Unfortunately, few
		ceiling fixtures allow one to mount the bulb base down or
have sufficient
		ventilation for the base to cool in any configuration.
		   On the other hand, I have table lamps with CFL' s with
the base down
		that have lasted several years.
		Al, K9SI
		aprssig mailing list
		aprssig at tapr.org

	aprssig mailing list
	aprssig at tapr.org

More information about the aprssig mailing list