Hi,
I am trying to control the speed of a DC cooling fan by PWM. The system basically consisted of a PIC18 controller board and a mosfet H-bridge board. The controller handles the user interface (LED, buttons, etc) and generates the PWM signal to drive the H-bridge. The problem is that the controller is located 5 meters away from H-bridge & motor. This is necessary because the mosfet is mounted on large heatsink and it looks ugly.
The system works okay, I used shield cable to carry the PWM to H-Bridge but I am worry any large EMI (e.g. mobile phone, microwave oven) will switch on all the MOSFETs at once. Should I use a different amp on the H-bridge to reduce EMI noise?
PWM signal = 22 KHz
Cooling fan = 12v DC @ 10 Amp
Any help will be appreciated.