View Single Post
  #5   Spotlight this post!  
Unread 06-07-2007, 01:57
Generalx5's Avatar
Generalx5 Generalx5 is offline
Hard Core Inventor
AKA: Jun(John) Zheng
FRC #1346 (Trobotics)
Team Role: Student
 
Join Date: Nov 2005
Rookie Year: 2004
Location: CANADA
Posts: 94
Generalx5 will become famous soon enough
Re: PWM translates to movement?

I got everything you explained except this part:

"but the output actually stays at zero for at least the theoretical 0-6 range, and it reaches 100 with an incoming pulse width that is somewhat less than 2.0 ms. It turns 1.0-1.5 milliseconds into a 100-0 reverse value, with the same holding at zero until it reaches 7 or so, and getting to 100 before the pulse width gets down to 1.0 ms."

Could you explain that a little more, what is the theoretical 0 - 6 range? does this mean there there is another IC chip that translates the pwm signals to a seperate pulsed signal that contains forward and reverse for the FETs? are there IC chips out there that are already programed to do that? I don't want to run into programming it etc...

Also, if I am switching current on a solenoid quickly, to prevent arcing, is it possible that I hook up two diodes in parallel but in opposite directions? is there a better solution to this other than using diodes? I know people use diodes to lessen the EMF from the collapsing field, but if im constantly creating, destroying fields, how would I handle the EMF? with currents up to something like 40 amps..

Last edited by Generalx5 : 06-07-2007 at 02:14.