79639RE: [Electronics_101] Re: OPI-ONE cables again...
- Dec 13, 2012I use temp sensors in many places around the house. My favorite is a series
string of four silicon diodes (1N4148). Each diode changes voltage with
temperature at -2.5 mV/C. Use four diodes and you get about -10mV/C. I
generate a 1.0 mA of current thru the diodes. What is your power supply
voltage? You use a resistor in series with your power supply, preferably a
12 Vdc supply to get your 1.0 mA of current. Then the voltage across the
diodes (or diode) is exactly inversely proportional to temperature.
I use an op amp to change the voltage gain and offset to get the band of
temperature desired. Then there is now the 0 to 5V needed for your
microprocessor A to D input.
That is how I would do it.
[mailto:Electronics_101@yahoogroups.com] On Behalf Of rtstofer
Sent: Thursday, December 13, 2012 3:10 PM
Subject: [Electronics_101] Re: OPI-ONE cables again...
[Non-text portions of this message have been removed]
- << Previous post in topic Next post in topic >>