Thanks for the responses.

To be clear, I'm not trying to alter the PWM output of the blower controller/porcupine to the blower motor, I'm trying to alter the voltage signal output of the PBU to the blower controller. It's a signal that varies between 2V and 7V. I don't know what current DC signals typically generate but I imagine it's a tenth or an amp or less.

I'll put the context aside and focus on center tap pots such as the model P271 described in http://www.bitechnologies.com/pdfs/p270.pdf This clipping looks like the inspiration for my diagram, though I've honestly never seen it before:



I don't know what CW and CCW mean other than the physical terminals of rotation but I'll treat them as terminal designations.

Question - what voltage will S see if CW has 2V, CT has 5V and CCW has 7V? Assume S is 20% of the distance between CT and CCW and resistance is linear across the sweep range.

Thanks,
Sixto
87 300D