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Discussion Starter #1
The LM34 integrated circuit temperature sensor
coupled with a cheap $3 Harbor Freight VOM special

gives direct Fahrenheit temperature readings.
I plan to epoxy the TO-92 package directly to

my motor and batteries. I already have one on
my solar hot water tank, powered with a 9 volt

battery. It operates from 5 to 30 volts.
10 millivolts per degree F!

John in Sylmar, CA
PV EV

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Discussion Starter #2
The problem with putting a sensor on the outside of a traction motor is that it is already too hot by the time it is picked up by the sensor. The things that burn out internally are probably already gone by the time the heat goes out the case. It is probably better to keep air flow through the motor(via a fan if necessary), and watch the current to establish a "norm" for your system rather than rely on a temperature reading.

Just my .02 cents

Mark Ward
95 Saab 900SE "Saabrina"
www.saabrina.blogspot.com




---- JS <[email protected]> wrote:
> The LM34 integrated circuit temperature sensor
> coupled with a cheap $3 Harbor Freight VOM special
>
> gives direct Fahrenheit temperature readings.
> I plan to epoxy the TO-92 package directly to
>
> my motor and batteries. I already have one on
> my solar hot water tank, powered with a 9 volt
>
> battery. It operates from 5 to 30 volts.
> 10 millivolts per degree F!
>
> John in Sylmar, CA
> PV EV
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev

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Discussion Starter #3
Mark Ward <[email protected]> wrote:
> The problem with putting a sensor on the outside of a traction motor is that
> it is already too hot by the time it is picked up by the sensor. The things
> that burn out internally are probably already gone by the time the heat goes
> out the case. It is probably better to keep air flow through the motor(via a
> fan if necessary), and watch the current to establish a "norm" for your
> system rather than rely on a temperature reading.
>
Of course you can't let the outside of the motor get up to a
temperature that would damage your motor. A reading is still good,
though, so you know what's normal and what's higher than normal.

I think the temperature sensor is a lot more useful on the batteries
than the motor, though.

-Morgan

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Discussion Starter #4
Seems like a lot more work than going down to Walmart and picking up a
digital thermometer with a remote temperature sensor for $8.

Other than the DIY aspect what is the advantage?

> The LM34 integrated circuit temperature sensor
> coupled with a cheap $3 Harbor Freight VOM special
>
> gives direct Fahrenheit temperature readings.
> I plan to epoxy the TO-92 package directly to
>
> my motor and batteries. I already have one on
> my solar hot water tank, powered with a 9 volt
>
> battery. It operates from 5 to 30 volts.
> 10 millivolts per degree F!
>
> John in Sylmar, CA
> PV EV
>
> _______________________________________________
> For subscription options, see
> http://lists.sjsu.edu/mailman/listinfo/ev
>


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Discussion Starter #5
Peter VanDerWal <[email protected]> wrote:
> Seems like a lot more work than going down to Walmart and picking up a
> digital thermometer with a remote temperature sensor for $8.
>
> Other than the DIY aspect what is the advantage?

You can interface it with a microcontroller, if you're making a car
computer/custom dash. For most people, though, the digital thermometer
is a better choice for its simplicity. It's not as much fun, though!

-Morgan

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