I am looking for a calculation to match a resistor network. I want to be able to measure the voltage of "n volts". The setup is like this: n volts | r2 | ADC---r1---4.7v | r3 | Gnd n volts will be 5 to 9.4 volts. r2 and r3 can be whatever. I would probably go with 10k for each. r1 is 10…

Resistor to math calculation

nickgammon February 25, 2012, 5:20am 5

I don't see why you need 3 resistors to calculate an unknown voltage in the range 0 to 10V.

On my page here for a robot car, I use two 10K resistors to detect when an 8V battery is getting low:

Topic		Replies	Views
Starting value of resistor R1 on voltage divider General Electronics	13	2700	May 6, 2021
voltage divider calculations General Electronics	6	2658	May 6, 2021
reading voltage Project Guidance	11	4025	May 5, 2021
Measuring Resistance - choosing resistor values? General Electronics	20	3791	May 6, 2021
Can someone confirm maths for voltage divider please General Electronics	13	4398	May 6, 2021