[VAC] Re: LED Ambience and lighting.

[Dr. Gerald N. Johnson, electrical engineer]

White LEDs are different technology from the far lower priced red and
orange and green LEDs. Different materials to produce blue light (which
took decades of research past red LEDs) which excites phosphors to get
the white components. Some of the selling price has to pay for that
research. Some has to pay for the different metallurgy to make the
semiconducting crystal.

Incandescent lamp prices are based a great deal inversely to the
quantity made. E.g. it costs a certain price to set up production for a
particular product and the 60,75 and 100 watt 115 volt lamps sell so
well that those lines run continuously while the 15 watt line runs
intermittently but the cost of line ownership is the same. 130 volt
lamps that sacrifice efficiency for longevity also cost a great deal
more than the common 115 volt lamps for the same reasons. Also the
sellers of lamps in quantity buy in huge quantities. 130 volt lamps will
probably never sell for a good a price as 115 volt lamps because the
last twice as long on the same line voltage.

Low power incandescent lamps like the 15 watt lamps you mention, are
also less efficient than 60 watt at up lamps because the thin filament
requires them to be operated at a lower filament temperature to have any
life at all. These days you can buy 17 watt fluorescent lamps with
edison bases for about $8 and reap a great deal more light for your
electricity money. Look at the twisted tubes from GE at Walmart.

Gerald J.



To unsubscribe or to change to a daily Digest, please go to
http://www.airstream.net/vaclist/listoffice.html

If replying back to this message, please delete all the unnecessary original
text from your reply.