Re: How Am I Going to Live with Energy-Saving Lightbulbs?




"abelard" <abelard3@xxxxxxxxxxx> wrote in message
news:vq6qf3h2hgef9d3pc3clgl062hetedapq3@xxxxxxxxxx
On Fri, 28 Sep 2007 08:47:56 +0100, Ar <Ar@::1.t> wrote:

On Fri, 28 Sep 2007 08:45:00 +1200, Roger Dewhurst scribed:

LEDs require a little over one volt DC! You could use one of those
black
wall plug transformers that put out anything between 7 and 16 volts DC
and
feed a string of LEDs wired in series. The trouble is those
transformers
are very inefficient and waste a lot of power.

Then get a switched mode power supply, more efficient, and more
expensive too.

what does switched mode supply mean....

It uses clever electronics rather than a heavy transformer to change the
voltage.

However transformers are not inefficient. They are just about the most
efficient power transducers that exist.

The wasted heat in LED systems comes from the power that the LED can't use.
Electricity flows only one way through a diode (what the D in LED stands
for) it flows both ways through most light sources, so half the power is
going to be lost anyway.

The gain comes because LEDs produce far more light per watt.

LEDs have other issues as well.

--
William Black


I've seen things you people wouldn't believe.
Barbeques on fire by the chalets past the castle headland
I watched the gift shops glitter in the darkness off the Newborough gate
All these moments will be lost in time, like icecream on the beach
Time for tea.




.



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