amberwolf wrote: ↑
Aug 14, 2018 1:28 am
How about taking a regular "ebike" hall throttle, mounting it in a box, running a cable from it via pulleys or gearing (to change the amount of travel/ratio of movement) to whatever control is actually going to be handled?
There's a few examples around the forum; the most recent similar is Cboy's ongoing thread for his motorcycle trike project.
You can also mount a bare linear hall sensor (honeywell 49x type) on something, and put magnets on the cable coming from the hand-control, positioned so they change the sensor's output in the range you need it to.
I bought normal 5 V Hall sensor (they are dirt cheap), which is centered around 2.4 V (i.e. the magnetic field is orthogonal to the sensor). I took a piece of aluminium and created this mount:
It is placed as follows in the old throttle
I then made a mount for the magnets as well. There is no problem with the slightly shifted magnets, since their poles are facing the same way. It is possible rotate the magnets to calibrate voltage, the mount for the Hall sensor allows for more degrees of freedom in calibrating.
The good thing about this is that the voltage is not linear, but instead a sine, i.e. it follows the function V(θ) = A * sin θ + C, A = 1.6 and C = 2.4. This allows for a smoother operation of the motor, since the first movements around zero yield very little motor thrust.
Voltron wrote: ↑
Aug 14, 2018 5:25 am
We use this one...
Yeah, I looked at that one before. It is a pretty good price. Might consider that in the future, if my current solution does not work properly.