Thread: How many CIMs in your drivetrain?
View Single Post
  #2   Spotlight this post!  
Unread 01-27-2016, 12:07 AM
ratdude747's Avatar
ratdude747 ratdude747 is offline
Official Scorekeeper
AKA: Larry Bolan
no team
  
Join Date: Feb 2009
Rookie Year: 2008
Location: Madison, IN
Posts: 1,061
ratdude747 has a reputation beyond reputeratdude747 has a reputation beyond reputeratdude747 has a reputation beyond reputeratdude747 has a reputation beyond reputeratdude747 has a reputation beyond reputeratdude747 has a reputation beyond reputeratdude747 has a reputation beyond reputeratdude747 has a reputation beyond reputeratdude747 has a reputation beyond reputeratdude747 has a reputation beyond reputeratdude747 has a reputation beyond repute
Re: How many CIMs in your drivetrain?
Quote:
Originally Posted by Jared Russell View Post
Maximum power and maximum efficiency occur at two separate points on the motor curve for brushed DC motors.

Maximum power occurs when P(out)=radial velocity * torque is maximized, which is at half free speed and half stall torque.

Maximum efficiency occurs when P(out) / P(in), or (radial velocity * torque) / (current * voltage) is maximized. This always occurs somewhere between the maximum power point and free speed (it varies from motor to motor depending on free current).
Quote:
Originally Posted by Ether View Post
The max power (rated power) of the DC brushed motors used in FRC occurs at roughly half the free speed.

The max efficiency occurs at a higher speed.

EDIT: Jared beat me to it.
Well, obviously I wasn't taught correctly. Then again, the class was using AC motors (both single and 3 phase), and with those, we found such to be true. Maybe inductive (AC) motors behave differently?

(Sorry for the misinformation, I feel kinda dumb here).
__________________
Dean's List Semi-finalist 2010
1747 Harrison Boiler Robotics 2008-2010, 2783 Engineers of Tomorrow 2011, Event Volunteer 2012-current

DISCLAIMER: Any opinions/comments posted are solely my personal opinion and does not reflect the views/opinions of FIRST, IndianaFIRST, or any other organization.