12-09-2004, 06:47 PM
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Re: Running electric blanket on DC?
On 3 Dec 2004 17:42:27 -0800, billb@eskimo.com (William J. Beaty)
wrote:
Quote:
Eric R Snow <etpm@whidbey.com> wrote in message news:<rvgvq0hgrsmpr61bnb14sm25o4clg6adhb@4ax.com>. ..
Greetings All,
I know this is silly but here it goes:
My wife and I keep our bedroom un-heated so it gets cold in the
winter. An electric blanket warms the bed before we get in. My wife
would like to keep it on all night instead of using all the extra
covers but is concerned that the "electrical magnetic field" emanating
from the blanket will give us cancer or something.
Does the blanket generate a strong EM field? WHy not find out?
If you hook a coil to the input of an audio amp, then listen to
the amplified output using headphones, you can easily hear the 60Hz
magnetism detected by the coil. For instance, wave the coil around
an AC wall clock motor, or around an old-style (non-electronic)
fluorescent light ballast. BUZZZZZZ! Once you can detect strong
AC magnetic fields, wave your coil around the electric blanket and
see if it's stronger than, say, standing under a fluorescent ceiling
light.
Here's a great little $12 amp. All hobbyists should have one
of these (I have several. They have lots of uses.) :
Mini audio amplifier w/speaker, 9V
http://www.radioshack.com/product.as...%5Fid=277-1008
That, a couple of mini-jacks, and a telephone pickup coil, and
you're ready to scan the environment for those lethal 60Hz hums.
Telephone pickup coil
http://www.radioshack.com/basket.asp...%2D533%2C&iGo=
When I did this years ago at home, I discovered that the whole
house was full of 60Hz b-fields. It was wired with old-style
knob-and-tube wireing, where all of the conductors are several
feet apart, rather than being twisted together inside a steel pipe.
((((((((((((((((((((((( ( ( (o) ) ) )))))))))))))))))))))))
William J. Beaty Research Engineer
beaty@chem.washington.edu UW Chem Dept, Bagley Hall RM74
billb@eskimo.com Box 351700, Seattle, WA 98195-1700
ph206-543-6195 http//staff.washington.edu/wbeaty/
Greetings William,
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Thanks for the link to the amp and the ideas to use it. I can already
think of other uses for it.
Eric R Snow
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