Re: OT: Phantom loads, was RE: Hydrogen

[XURQ03A@prodigy.com ( LEE A HART)]

The usual "wall wart" setup is a cheap transformer, rectifier, and filter
capacitor. If it is powering electronics, there will be a linear voltage
regulator in the device being powered. Sometimes the capacitor or rectifier
are also moved to the other end of the cord, i.e. they're inside the product
being powered; but overall, the circuit is the same.

This type of power supply has a power factor of 0.5-0.7 and an efficiency of
60% or less. The "or less" is important, because wall wart transformers draw
almost as much current no-load as they do at full load. Most things plugged
into wall warts are off or on standby most of the time, so efficiency is zero
most of the time.

I have several small solar panels around my house, powering things that would
otherwise have wall warts. At present there's a cordless soldering iron,
cordless vacuum cleaner, and a nicad battery charger (used for the nicads in
my walkman, multimeters, shaver, and other miscellaneous gadgets). My old
laptop computer (a Radio Shack model 100) used to be powered by a solar panel,
but modern laptops take far too much power to make this practical any more (progress...)

Lee Hart                     If you would not be forgotten
4209 France Ave. N.          Soon as you are dead and rotten
Robbinsdale, MN 55422 USA    Either write things worth the reading
phone (612) 533-3226         Or do things worthy of the writing
e-mail XURQ03A@prodigy.com   (Ben Franklin, Poor Richard's Almanac)