# How to shift resistance range of Linear Potentiometers by X ohms in the Positive or Negative direction?

For example, I have a 10k ohm (linear) Thumbwheel Potentiometer. This POT will produce values from 0 to 10k when reading its resistance.

## Positive Shift

• How do I shift resistance range values by X ohms in the positive direction? E.g. a 10k POT will yield a new range of: 10 to 10,010 ohm, shifted by 10 ohms? Since I am using an Arduino, I could programmatically scale the resistance value. But I do not want to do that.

## Negative Shift

• How do I shift resistance value range by X ohms in the negative direction? E.g. a 10k POT will yield a new range of: -10 to 9990 ohm, shifted by 10 ohms?
• You mean to just add $X$ $\Omega$ to the resistance? Feb 9, 2015 at 16:21
• Yes, to shift the range? Feb 9, 2015 at 16:56
• @lucidgold, point is, is X always positive, or do you want a solution for negative X also? Feb 9, 2015 at 16:59
• How do you intend on using a resistance of -10 ohms? Feb 9, 2015 at 17:51
• As you have drawn the connections, you are not using the potentiometer as a variable resistance, but as a variable voltage. The analog input to the Arduino draws almost no current, causing almost no voltage drop on any resistor you put on the middle terminal, so it won't have any effect. Remember that the analog input reads voltages, not resistance. Do you want to shift the voltage by a certain amount? Feb 9, 2015 at 23:30