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Glenn W9IQ
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Thanks for the good interaction via comments to your question in order to better understand the working conditions and desired behavior of your proposed control circuit.

Here is a simple implementation of ESCin=5 volts * %V{limit} * %R1 as we discussed via comments:

schematic

simulate this circuit – Schematic created using CircuitLab

One very important detail is that whatever I add should not be able to generate a phantom signal, i.e. Vout MUST be always less or equal to Vin, even in the event of software bugs and reasonable hardware failures.

It certainly meets this requirement. The only failure mode is if Vlimit has the possibility of exceeding 5 volts.

A potential disadvantage of this circuit is that the operator control range rescales. But since the operator's feedback is sensory, this may have minimal impact, particularly if you can ramp in your Vlimit control voltage via your ADC.

Another version of this would be to take the wiper output of the pot, resistively scale it if necessary, and then use that as the Vref for the ADC. You can also add common mode decoupled buffers as necessary to ensure low noise inputs throughout.

Glenn W9IQ
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