Motor Control - Minimising RFI

Thread Starter

daba1955

Joined Apr 27, 2019
85
A project I am involved with is using an Arduino microcontroller with PWM to control the speed of a brushed dc motor.

I am trying to use the commonly available EV1527 remote control receivers to effect start/stop & speed increase/decrease functionality, but I am finding that the receiver has a much degraded performance (in terms of transmitter to receiver distance) while the motor is running.

I have tried to shield the RF components from the motor wiring as much as I can, and added as much motor wiring filtering as I can justify, but I still get a degrading interaction..

Simple question - would using a brushless motor alleviate the problems we are having, thus eliminating any commutator switching and arcing that is inevitable on a brushed motor.

Happy New Year to all....
 
Simple question - would using a brushless motor alleviate the problems we are having, thus eliminating any commutator switching and arcing that is inevitable on a brushed motor.
Likely.

A ceramic cap at the motor terminals might help.

Shielding helps eliminate RFI. e.g. Shied the motor power cable. Connect shield at one end only. Usually the source side if possible.

Twisting helps eliminate EMI,

A lot of cabling is twisted pair shielded.

I used shielded power cables in an initial design once. A vacuum chamber with an RF transmitter operating inside the chamber and 3 each, phase angle fired IR heaters inside the chamber.
 

MaxHeadRoom

Joined Jul 18, 2013
20,405
You may find improvement by experimenting with lower PWM frequency, I generally use as low as possible, Picmicro recommend starting at around 5Khz.
There is less EMI with a BLDC motor.
Also
 
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