# Contactless potentiometer for an accelerator on sim racing pedals

Hi i’m looking at this for my pedal position reading MP1-L-0025-103-5%-RH
wil it work if the movement is round? Like on a 1.5’’ diameter or it will be out of range of the linear pot?
Thanks

@DigiKey_Internal
Can I get help with this question please

Hello @Drivenlogic ,

Thank you for your inquiry. The magnet would have to move across the part in a linear motion. This video may help illustrate this: https://www.youtube.com/watch?v=dC7qukOZS4s

We also carry round ones:

MP1-R-0046-353-103-5%-RH

• This example is much larger than the 1.5"diameter. The magnet would have to swing around in a circular motion over the sensor.

Yes, This is what i’m looking for but i don’t need 360 deg so i wonder if a linear would work if the motion is around a pivot point?

That defines a circular arc.

If the radius is large enough, the angular rotation is small enough, and the magnet is wide enough you could use a linear track.

I think you will get a non-linear output due to the arc motion of the magnet across the surface. (haven’t finished my coffee, or done the math, so it’s only a guess)

It will be far easier to design it to use a circular track.

What kind of signal does your pedal system take?

If it can use a linear voltage change, rather than just a resistance change, then you might also want to consider a rotary angle sensing Hall magnetic sensor. These output a varying voltage based on the angle of a magnet attached to your pedal.