"Mike" wrote in message
...
Bill Stock wrote:

Thanks Mike, I get the V=I*R. Although it's been a good number of years
(decades) since my basic electronics course. It just surprises me that
the
amperage specified per foot, would not be for a given voltage. For
example:
I tried to test my wire using a variable power supply (3A/35V) a built a
number of years ago. But the wire never did start to glow before the PS
smoked itself. Everything past the regulators got fried. The regulators
have
thermal protection and there is a fuse on the mains side, so I guess the
parts (diodes/caps) were underrated. It should not be a big deal to fix
these components. But I'm surprised I did not get some colour out of the
wire at 3A/35V.

400F is pretty dark, as an example - look in your oven set to 450F - it
doesn't glow (visible) red. 35V would have tried to drive lots more than
3A
through the wire - more like 12 if I remember your numbers (in the bit
bucket
now) that would fry a 3A supply.

mike

Thanks Mike.

I think I solved the mystery yesterday. I picked up a cheap switching PSU at
the surplus store to continue my experimenting. But I still wasn't getting
much heating. So I decided to check the resistance of my test wire and it
was 3+ x what I expected. It turns out that the vendor shipped me the wrong
wire, 3.5 ohms/ft, not the 1 ohm/ft I ordered. They're shipping the correct
wire, so this should solve my problem.