Potentiometer In Parallel

Thread Starter

ilnar

Joined May 8, 2012
16
here is my potentiometer and it's wiper is connected in parallel with 12k resistor.
my wiper also serves as an output . so... how do i order this circuit to output 2.1 volts?
 

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cork_ie

Joined Oct 8, 2011
428
R= total pot resistance and assuming it is a linear potentiometer

2.1 Volt is dropped across 20% of your pot,
2.9 Volt across 12K & 80% of your pot in parallel.

[0.2R= 2.1/I ] & [ 1/ (1/.8R + 1/12000)] = 2.9/I =>

10.5/R = I = [2.9 x (1/.8R +1/12000)] = [2.9/.8R + 2.9/1200]

= 3.625/R + 2.9/12000 =>

6.875/R = 2.9/12000 =>

R= (12000x 6.875)/2.9 = 28.448K

Theoretical Pot size to get 2.1V at the wiper as in your drawing is 28.448K
In practice you are unlikely to get one outside a standard value
 
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