PWM Motor Questions

Thread Starter


Joined Nov 16, 2006
Hey Forum
Iam using a Pic 16f877 to control a DC motor with PWM.
The setup is extremely basic with a HEXFET driving the
At the moment i have everything working and i have just made
an improvement on the audible noise coming from the motor by
increasing the PWM frequency.
I have alot of questions regarding PWM and DC motors, i dont even
know where to start (e.g effects of PWM on brushes of motor,
what is a good frequency and how does it effect the torque of
the motor, effeciency, EMC noise due to using PWM on a dc motor
that is EM frequencies coming from brushes and leads).
So as you can see even though i have an extremely basic circuit i have
to wonder what massive improvements can be made to improve the
circuit and would they be worth it. Iam finding it very difficult to get some honest and useful information on this, its easy get information on PWM and easy get information on DC motors but not on PWM&DCmotors.
I guess what i need is to draw on somebodies experience and i would appreciate any pointers or direction to comprehensive documentation on
this subject.



Joined Dec 3, 2008
i am standing at the same position whr u r but i have some exp in using pic16f886. so r u able to provide me the data , schematic and code of that program so that i can do the same at home and learnthe skill as quickly as possible.plz do my fever