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is there an electrical component that exists that would act similar to a potentiometer, but could be turned either clockwise or counterclockwise past a middle point, and would either release positive or negative voltage depending on which direction past that point?

So for example, you would turn it left to release a negative voltage, and turn it back to the right to release a positive voltage.

If this doesn't exist, is there a simple circuit I could create to emulate this ability?

Thanks

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Here you are:

schematic

simulate this circuit – Schematic created using CircuitLab

Yes, it's exactly the same circuit you've already been doing with ground in a different place.

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  • \$\begingroup\$ Sorry, but could you briefly explain the diagram to me? \$\endgroup\$ – LimitedBacon Feb 18 '15 at 2:57
  • \$\begingroup\$ The diagram is a potentiometer where ground is not connected to one of the ends of the potentiometer, but is instead at some arbitrary point in between the two ends. \$\endgroup\$ – Ignacio Vazquez-Abrams Feb 18 '15 at 3:15
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    \$\begingroup\$ I would like to comment that for this application the potentiometer should be one selected as a 'linear' resistance characteristic. Any tapered or log curve pot will not have its half resistance point in the center of rotation. \$\endgroup\$ – Michael Karas Feb 18 '15 at 4:42
  • \$\begingroup\$ Assuming both voltages are equal. It is possible to use unequal voltages with a log or antilog pot and end up with 0V in the middle of the dial, although I can't come up with any use cases for such a setup. \$\endgroup\$ – Ignacio Vazquez-Abrams Feb 18 '15 at 18:12

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