×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

DC brush motor issue

DC brush motor issue

DC brush motor issue

(OP)
Hi,

I met a problem with a DC brush motor recently. The whole system is relied on a DC motor controller and a small DC brush motor from Maxon in a current control mode. The current through the motor is adjusted by a analog output from a DAQ card directly. Recently we noticed that when the current is close to the maximum current on the amplifier, it will drop automatically.

Is it a standard problem seen in the DC motor control?

Another potential issue with this system is that the PWM driven current went through a cable 10 meter long. Will this be an issue too?

Best.

Ming

RE: DC brush motor issue

Some output stages and power supplies have so called "fold-back" current limit that behaves just like that. It does so in order to prevent the transistors from overheating.
I guess that is what happens in your servo. What type is it and how much current is the motor drawing when it happens?

Gunnar Englund
www.gke.org
--------------------------------------
Half full - Half empty? I don't mind. It's what in it that counts.

RE: DC brush motor issue

(OP)
Than you for the quick reply. We had an ADS 50/10 and its theoretical current capacity is set to be 10A. However, the current drop can happen at 4A based on the feedback signal from the controller. There is a secondary current limit on the controller which should not be activated, however, it seems that this current limit might be on.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources