problem with Mr. noise

hi all

I designed a PCB board with 16f84a microcontroller for a motor
and operate normally.

when I put a PCB board beside the motor does not work normally.


I think my project effected by noise and I need a solution with it.

I need to isolate the frequencies of motor away of frequencies of a PCB board.

I NEED YOUR HELP.


best regards

Your description is far too vague!.

For a start, do you have the normal supression components around the motor? - post a COMPLETE circuit, showing EVERY component.

HAMZAZAYYAD said:

hi all

I designed a PCB board with 16f84a microcontroller for a motor
and operate normally.

when I put a PCB board beside the motor does not work normally.


I think my project effected by noise and I need a solution with it.

I need to isolate the frequencies of motor away of frequencies of a PCB board.

I NEED YOUR HELP.


best regards

Click to expand...

The only obvious thing that comes to mind is that your PCB isn't covered and is touching the metal casing of the motor. I am making the assumption that the casing conducts electricity. If I am correct, then you may have created a short circuit.

and a Printed circuit board cannot generate frequencies unless it is used with an oscillator circuit.

That sounds like a fairly typical EMC problem--either the rotating magnetic field or RF noise from the brushes (if present) is getting into the board + causing interference. Possible solutions (in order of complexity) might be:

-Move the controller away from the motor.

-Switch to a lower-noise motor.

-Shield the controller by placing it in a conductive, grounded box (a steel box is recommended due to its magnetic properties). Also, consider adding a ground plane to the controller board.

-Shield ALL lines going in or out of the controller and / or position them away from the motor--this includes power lines. Also, power lines should be filtered when they enter the controller board.

-Reposition the controller to minimize specific types of interference (ie, no pulsing B lines normal to the board).

-Harden the controller itself against interference by identifying / minimizing sensitive points. For example, signal lines should be low-impedance to minimize induced voltages.

-Get the device to an EMC lab and do a proper analysis on the noise output / susceptibility for all components. Use the results to make the appropriate modifications.

-Get a copy of Maxwell or some other EM simulator and do basically the same thing.