# potentiometer working?

i have a rotating 10k pot with three terminals - red, yellow and black. i connect red to arduino 5v and black to arduino gnd and yellow to arduino analog pin. may i know what will be the path of current when resistance is 0 and when the resistance is 10k i.e. full -- 1)from red(5v) to black(gnd) 2) from red to yellow

Path of current in all cases is +5 thru the resistor to Gnd assuming you have the outer legs connected that way and the wiper going to an analog input. The analog input only draws 1uA of current, the 500uA going thru the pot is the main current flow.

CrossRoads: Path of current in all cases is +5 thru the resistor to Gnd assuming you have the outer legs connected that way and the wiper going to an analog input. The analog input only draws 1uA of current, the 500uA going thru the pot is the main current flow.

So if i set my potentiometer to 0 ohms theoretically i will be shorting 5v of my arduino with arduino ground. infinite current will flow. Will that damage my chip? i have arduino uno.

zacmackra: So if i set my potentiometer to 0 ohms theoretically i will be shorting 5v of my arduino with arduino ground. infinite current will flow. Will that damage my chip? i have arduino uno.

If you connect a potentiometer across a voltage source, that voltage is "distributed" across the entire potentiometer. Rotating the shaft moves the internal wiper to various places in the potentiometer and "picks off" whatever voltage is at that point.

If you have a linear potentiometer, the voltage is "distributed" evenly across the resistance element. So, for example, 1/2 way along (50 percent) the resistance element, 1/2 of the applied voltage exists (i.e. 2.5 volts). All the way towards the ground end, the voltage is 0% or 0v. At the other end the voltage is 100% or 5v.

That voltage, however, is "going into" a very high impedance point (the Arduino analog input pin) so very little current flows.

At no point is anything "shorted out".

Make sense?

(edit to add): Assuming you have the potentiometer setup like this:

5 volts ----/\/\/\/---- ground ^ |-------- arduino input

That really makes sense.....thanks Krupski.