Temperature Sensor on Aux Input

General Topics for configuring, operating and tuning the Megajolt. Also see the <a href="http://www.autosportlabs.net/MJLJ_V4_Operation_Guide">Operation Guide</a>

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FULMNTE
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Temperature Sensor on Aux Input

Post by FULMNTE »

So I have the resistance vs. temp profile for the autometer temp sensor I want to use on the Aux Input of the MJLJ.

I also know that the Reference Voltage is 5 Volts.

Now what is the bias resistance to translate the Input Ohms into Input Volts? Is it a 'standard' 2490 Ohms?

Thanks!
1971 Monte Carlo, 454 HO, Tremec 5 Spd, Weiand 177 Supercharger

brentp
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Post by brentp »

If it's a 1-wire probe, this wire will go to the aux input, and the other will be conducted through the body of the sensor to the engine ground connection.

Calibration can be done here:
http://www.autosportlabs.net/MJLJ_V4_Op ... figuration

There is a table of 255 values; the default calibration is 0v = 0 on the gauge and 5V = 255.

You can change the calibration, or "mapping' of these values to whatever you want.

One way to do it is heat the sensor to a known value, observe the raw 'uncalibrated' value, and then enter that in to the table. You can repeat this for each cell. If the sensor is linear (most likely) you can take 2 or 3 temperature readings- cold to hot, and plot a graph using excel, then import it into the configuration software.

Hope this helps.
Brent Picasso
CEO and Founder, Autosport Labs
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