John Ferrell wrote:
> [...] Ordinary diodes work well as heat sensors,

Indeed they do.  And transistors.

But one can get tired of dealing with the associated components; as
the TI appnote says [1]; for excitation, offsetting, and amplification.

To integrate diode and associated components, go for an LM35 [2].

To use digital transmission and (probably) delta-sigma remote ADC, go
for a DS18B20.

To put more smarts into the remote assembly; like an indicator or
switching, go for an an ATtiny85 eight-pin MCU with on-board
temperature sensor.

Or perhaps a digital interface and separate the diode from the
conversion; an LM95235 [3]?  So diode not affected by heat of the
conversion.

So many choices, so little time.  ;-)

References:

1.  http://www.ti.com/lit/an/sboa019/sboa019.pdf
2.  http://www.ti.com/lit/ds/symlink/lm35.pdf
3.  https://www.arrow.com/en/research-and-events/articles/using-a-simple-di=
ode-as-a-ballpark-temperature-sensor

--=20
James Cameron
http://quozl.netrek.org/
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