Actions
Forum Thread Details
  • State Verified Answer
  • Replies 9 replies
  • Answers 1 answer
  • Subscribers 395 subscribers
  • Views 935 views
  • Users 0 members are here
Related

DC motor very slow discharge, mosfet to small ? 5v circuit.

Former Member

Been playing around with a DC motor #learningByDoing

 

And found for some reason, my DC motor wont discharge at a normal rate/instant,

It's as if it keeps power, but it's slowing down, slower.. slower.. slower..  until it finally stops.

 

image

The motor is connected to the black/red wires to the left, and have a diode as fly back.

 

It's grounded through the P-fet in the top, via the red wire, and green to ground.

Yellow is the signal from the arduino on port A0,

 

See the video --

 

 

So what am i doing wrong here, since the charge is not instant?

 

any ideas ? image

Parents
  • 0

    Hi Martin, I would put the motor and PFET on a seperate power supply and see what happens. Also you could look to see what is happening voltage wise or PWM at the gate of the PFET as this is what should control the motor speed. I do not know what your control circui or logic looks like so it is difficult to comment further. Interesting phenomenon and my curiousity is peaked. Look at your voltage changes preferably with a scope and trace back to the cause.

    John

Reply
  • 0

    Hi Martin, I would put the motor and PFET on a seperate power supply and see what happens. Also you could look to see what is happening voltage wise or PWM at the gate of the PFET as this is what should control the motor speed. I do not know what your control circui or logic looks like so it is difficult to comment further. Interesting phenomenon and my curiousity is peaked. Look at your voltage changes preferably with a scope and trace back to the cause.

    John

Children