banh
Advanced Member level 1
i have a variable resistor R2 with value ranging from 5-111 Ω. i think of the following circuit which has another R1 of 39 Ω in series with R2.
V1 is shot into the MCU ADC pin.
here we have \[ V1 = \frac{5V}{R1+R2} \times R1\]
--> the relationship between V1 and R2 is of course not linear but i think still acceptable..
the problem is the circuit draws too much current (can be up to more than 0.12A) as 5V supply is also shared with the MCU.
is there any way to improve?
V1 is shot into the MCU ADC pin.
here we have \[ V1 = \frac{5V}{R1+R2} \times R1\]
--> the relationship between V1 and R2 is of course not linear but i think still acceptable..
the problem is the circuit draws too much current (can be up to more than 0.12A) as 5V supply is also shared with the MCU.
is there any way to improve?
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