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I need to vary the resistance between two points in a circuit, so I bought a DS3502 digital potentiometer to use as a rheostat. The issue is that I made a rookie mistake, and thought that I could vary the 0-10kohm range into a 0-10 ohm range just by adding a parallel 10 ohm resistor, not realizing until the chip had already arrived that the non-linearity is extreme (going from level 0 to 1 on the digital pot goes from 0 to 9.1 ohms, if my calculations are correct)

Is there a way to divide this resistance in a way that is more linear? I dont need even close to perfect linearity, but at least having a dozen or so levels before getting to 5 ohms would work for me. If it helps, I have 5 of these chips, and can combine them if there is a clever way to do so.

Note that I am not asking for a voltage divider, I specifically need the resistance to vary even independent of any volage applied

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    \$\begingroup\$ Maybe take a step back and explain why you need a 0 to 10 Ω digitally controlled floating resistance. It's possible that there's a different way to solve the overall problem. \$\endgroup\$ Commented Aug 29 at 17:55
  • \$\begingroup\$ Fred, you probably need to expose your hand and show us what's going on. You have 5 10k digital pots. Put them into a small drawer for some later purpose. \$\endgroup\$ Commented Aug 30 at 5:37

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Is there a way to divide this resistance in a way that is more linear?

No. Not with a 10 kΩ digital potentiometer.

There are ways to implement a digitally-controlled 0 to 10 Ω, but the best one depends on what your ultimate problem is. Please note what @Dave Tweed said in a comment and do as he said.

Based on other questions you asked in this forum, I guess you're working with DC motors. If so, note that a 0 to 10 Ω rheostat is not how you vary the speed of a DC motor. Instead, you need a "motor controller" or an "electronic speed controller" (ESC). Get one that includes a digital link to control the speed.

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