John Fields wrote:
Ah-HAH! I'm finding out more and more about these sensors. So even tho
they're only three leads, ground, power and output, they have more than
a single sensor inside?
Yes. AFAIK there are three types of materials used in the sensors:
lithium niobate, poled polyvinylidene fluoride, and a ceramic of some
sort. Almost all of them internally use two tiny rectangular sensors
which generate an electrical signal when they're heated, (or cooled)
and they're connected differentially so that if they're both heated or
cooled at the same rate the net output from the pair will be zero. A
lens is used in front of them so that as a warm object moves across
them the image will be focused when it hits them, and as the spot
traverses the pair it generates the desired output, which is usually
cap-coupled and severely bandwidth limited and eventually used to
makes the yes-no decision about whether to turn on the lights, or
detonate the bomb, or whatever.
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That's good to know, thanks.
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You're welcome.
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Maybe that's why
J.T. suggested two lights spaced 3' apart.
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More than likely, but you can do it just as well with a single
off-normal lamp, and I'd put it farther away from the center line than
18 inches just to make sure it's not hitting both sensors equally.
My 100 watts is probably way overkill, too, since we humans radiate
about 100 watts from a rather large area, so you could for sure get by
with less from a point-ish source like an incandescent lamp.