How about electric blankets? Do they pose any health risks?
Hard to tell, but probably less than those of say power lines. Early
electric blankets were wired differently than more recent blankets. The
older ones used a single resistance wire snaked back and forth throughout
the blanket.
hot ---------------|
|
|--------------|
|
|--------------|
|
neutral ------------|
The more recently made ones twist the wires together like this
This twisted wire is then woven through the blanket. Note that the twisted
wire is covered in insulation so that the two directions are electrically
isolated from each other. Since the two currents are moving in opposite
direction and are the same size, if the twisting is sufficiently tight, it
should reduce the net electric field through cancellation of the two
oppositely signed fields.
Does it? I don't know for sure, but I am going to give it a try this year in
class. I will report back any results.
Marc Kossover
mkossover@newman.k12.la.us
"Teaching is five shows a day" -- Dema Harriman Solberg