Thread: Small motor used as sensor
View Single Post
  #6   Spotlight this post!  
Unread 07-02-2006, 09:31
Mark McLeod's Avatar
Mark McLeod Mark McLeod is offline
Just Itinerant
AKA: Hey dad...Father...MARK
FRC #0358 (Robotic Eagles)
Team Role: Engineer
  
Join Date: Mar 2003
Rookie Year: 2002
Location: Hauppauge, Long Island, NY
Posts: 8,855
Mark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond reputeMark McLeod has a reputation beyond repute
Re: Small motor used as sensor
We are using the small KOP Mabuchi motor as a tach for velocity control on our shooter and it works very well. The response is linear and the Mabuchi spec is a near perfect fit for our design speeds. There is additional noise from the commutator, but it's regular and we smooth that somewhat in software and set our tolerances to avoid reacting to it.

We added a diode to limit current to one direction and an adjustable pot to bring the output into the 0-5v range. You can also add caps as Ken suggested, but it's not necessary.
__________________
"Rationality is our distinguishing characteristic - it's what sets us apart from the beasts." - Aristotle
Last edited by Mark McLeod : 07-02-2006 at 09:34.