View Single Post
  #33   Spotlight this post!  
Unread 20-12-2005, 15:05
Unsung FIRST Hero
Al Skierkiewicz Al Skierkiewicz is offline
Broadcast Eng/Chief Robot Inspector
AKA: Big Al WFFA 2005
FRC #0111 (WildStang)
Team Role: Engineer
 
Join Date: Jun 2001
Rookie Year: 1996
Location: Wheeling, IL
Posts: 10,798
Al Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond reputeAl Skierkiewicz has a reputation beyond repute
Re: Cheapest and easiest way to slow down a motor

There are only three parts, the battery on the left, a pot in the center and a transistor on the right in series with the motor. The transistor will need to be mounted to a heatsink because it will get hot. As you move the pot, a varying amount of current will be supplied to the transistor base thereby controlling the current in the collector/motor. With the wiper all the way up at 12 volts, the motor will be at max speed. Start with a 10K pot but you may need a 100k pot depending on the range you need and the gain of the transistor.
As an alternative, you could use the speed control from a 12 or 14 volt drill too or the motor control from a car blower which is usually three resistors and a switch.
__________________
Good Luck All. Learn something new, everyday!
Al
WB9UVJ
www.wildstang.org
________________________
Storming the Tower since 1996.