Society of Robots - Robot Forum

General Misc => Misc => Topic started by: W. ZEE on July 23, 2010, 05:23:01 PM

Title: RE: 360 degrees continuous rotation potentiometer
Post by: W. ZEE on July 23, 2010, 05:23:01 PM
  Awhile back Ro-BOT-X......asked about a 360 degree Potentiometeter.  It's been some time since anyone has posted on that
  subject so I've made it as a new posting. Hopefully Ro-Bot-X will see it.
  Piher North America, makes a Panel Mount Style Sensor that has an accuracy of 0.5% at 360*.  The sensor incorporates 
technology that is sensitive only to the flux density coplanar with the I.Cs surface. optimizing accuracy for absolute position feeding back from 0 to 360*.  The package maintains a true noncontacting air gap between the rotating magnet and the fixed sensing system. PSC-360 / $20 in production Quantities.... notes from EDN June 24th.
www.pilher.net (http://www.pilher.net)
    I don't know if this would be helpful but it struck me that it might be of interest.   Regards, ZEE
Title: Re: RE: 360 degrees continuous rotation potentiometer
Post by: Ro-Bot-X on July 23, 2010, 08:17:51 PM
Thanks, but something similar has been found and used to improve servo's accuracy. A complete solution to change the electronics in a servo, making it "smart" an more like the Open Servo concept. See it here:

http://www.societyofrobots.com/robotforum/index.php?topic=10788.0 (http://www.societyofrobots.com/robotforum/index.php?topic=10788.0)

I did not use it yet, I came to the conclusion that servos are a bit noisy (loud) for continuous rotation, as opposed to some geared motors. But the magnet could be glued to the back axle of a geared motor and that system can be used as an incremental encoder OR an absolute encoder, so basically you can transform any geared motor in a 360 degrees servo with no hard stop. I think this functionality is similar with that of the Lego NXT motors.