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I'm researching conductive fabric with a surface resistivity <0.5Ω/m2 (unstretched).

I've used a voltage divider setup to connect with an ADC pin of microcontroller (ATMega/Arduino board).

This setup works, but the fabric gets hot to the touch.
I suspect this is due to the low resistance and too much current going through. Is this correct? Are there other possibilities for this occurrence?

Shabab
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yair99
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  • Correct. If you want resistive touchscreen style sensing, you'll need something with a much higher unit resistance. – pjc50 Nov 25 '13 at 16:34

2 Answers2

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an offline friend just suggested using a wheatstone bridge.

jfa
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yair99
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  • That is a good way to make sensitive measurements of resistance effects by comparison to resistors of known values. Careful selection of the rest of the resistances in the bridge will allow you to limit the current flowing in the sensor patch. – RBerteig Nov 25 '13 at 19:45
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The lower the resistance the more current. This is Ohm's law:

$$V = I * R$$

if we rearrange it, it is easier to see that if we increase the resistance at a given voltage, current will drop:

$$I = \frac VR $$

And when more current flows through a conductor/resistor more heat is transfered to the surroundings.

More current gives more heat.

EDIT: You basically have this circuit so you can relate the formulas:

Simple Ohm's law example circuit

uniquenamehere
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