I am trying to figure out a way to trigger a switching signal using a bipolar nema 17 stepper motor, without altering the wiring. An example would be to turn on/off an LED when change in speed or direction of the nema 17. Without attaching anything into the wiring or the core/shaft.
Could a bipolar hall effect sensor do this? There is always a magnetic field? Could It read the changing field created by the coil charge only. (Micronas HAL115US). If this would work, I could figure out the transtor switching circuit I need. If there is an existing magnetic field that wouldn't allow change the status of the sensor, then that option is out.
If that wouldn't work, use the hall effect sensor with a split ferrite ring to make a dc current sensor slipped over one of the motor wires? I read about this, but not exactly sure how to build it. If this is a better option, worth figuring out how to accomplish?
Any ideas? I would really like an option to just put it in the motor and take it off for another motor.
Thanks! Ed