Jump to content
Electronics-Lab.com Community

Precise rpm at changing loads

Recommended Posts


I got an old 3 1/2 inch disk drive and of course I want to use some parts of it. The most interesting part however is the small stepper motor (bipolar). Connecting it to the shaft of another motor will produce voltage output on the two output coils which can be converted to digital and be used for precise rpm measurement (like in a frequency counter) Using DC-motor to drill PCBs (sometimes five in a pack) the rpm drops considerably while the drill works itself through the FR4. My idea is to compensate the drop vai this stepper. The signals of the stepper can be compared with the signal of the selector and then trigger the PWM drive for wider pulses or a higher frequency or both.

Any idea to start with?

Kind regards


Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...