longobord at gmail.com
Thu Feb 11 21:04:40 PST 2010
Nichrome seems to make sense if we were going to go with electric heat,
which is probably a good idea for keeping the camera lens defogged/frost
free. I wouldn't want to use it for much else, and also probably focusing
on trying to get thermally insulative materials whenever possible. (Which
means aluminum is right out.)
What would the purpose of the 555 chip be, though? I don't think the
nichrome would work with PWM very well, although I might be mistaken. Then
you'd have to have a circuit to drive the 555 and...
I understand a thermistor, if well-positioned, could be instrumental in
controlling the current, but if you have a well-designed circuit to limit
current flow, wouldn't the thermistor be all you need? What would the
circuit you have in mind look like?
Possibly using it in a wheatstone bridge or some other tuned simple circuit
could be employed to good effect to run the nichrome, don't you think?
"The road of excess leads to the palace of wisdom." -- W. Blake.
The outer bounds is only the beginning.
On Fri, Feb 12, 2010 at 5:31 AM, Jonathan Moore <moore at eds.org> wrote:
> So I was thinking about heating and it struck me that we could use a
> thermistor, 555 timer, and nichrome wire to get the job done. The
> thermistor would be used to set the duty cycle of the 555 which would
> drive the nichrome wire so that as the thermistor got colder the duty
> cycle of the 555 would increase and run current thought the wire
> What do people think of this idea?
> Space mailing list
> Space at lists.noisebridge.net
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