Help with circuit for motorized faders

[abbey road d enfer]

I think we used to call that "stiction", friction to overcome to get something moving.

JR

Sometimes we use the word "collage", which means gluing/sticking, but more generally adherence, same word as in English.

 

[JohnRoberts]

Sometimes we use the word "collage", which means gluing/sticking, but more generally adherence, same word as in English.

OK here's an old friction/physics joke...." two cats were sliding off a sloped roof, which one fell off first?  The one with the smallest mu..  ;D "

JR

 

[abbey road d enfer]

OK here's an old friction/physics joke...." two cats were sliding off a sloped roof, which one fell off first?  The one with the smallest mu..  ;D "

JR

Do they really make physics jokes ar kindergarten?

 

[zamproject]

PID stuff from Bob Pease, it can be quite simple at times.  I suppose it could be downgraded by an Arduino

Enjoy

Martin

I played with software PID (and PWM  motor diver) at early prototype of my system. I'm not that good at code so I don't tweak the digital PID that much, but I suspect you can't go that fast and not overshooting due to computing time.
IIRC the faster I can achieve without overshooting (which mean reverse move to apply but not to fast or you oscillate) was around 200/250ms. With faster setting you can travel in 100/150 ms to target but overshooting (a lot), and the system need more or less the same time to finaly reverse and hit the target.
Analogue PID is about 100ms. minimal or no over shoot (you can barely see it, sometimes)

So it really depend of what efficiency and speed you expect from a motor/automation fader system.

Best
Zam

 

[JohnRoberts]

Do they really make physics jokes ar kindergarten?

Nah they don't learn Greek  or Physics in kindergarten... (mu is the coefficient of friction ) so cat with less friction slides off the roof... I think this was a high school or early college memory trick to help physics students remember what mu means.

JR