Goodmorning to everyone.
I’m trying to control an brushless air pump with a MOSFET. I’m gonna decribe you the sutup and then explain the issue.
In the attachments there is the circuit pic.
- MOSFET is a IRLB8271 (https://cdn-shop.adafruit.com/datasheets/irlb8721pbf.pdf) gate to PWM, drain to negative pole of the motor, source to ground
- the resistor is a 10kOhm resisitor, and actually connect pwm cable to gnd (the fitzring circuit is wrong)
- I’m using an arduino MEGA, but I don’t think it matters
- the diode is a 1N4007 ( http://www.farnell.com/datasheets/1505911.pdf?_ga=2.244684930.661679428.1527063116-234452469.1527063116 )
- the power supply is a Laboratory Power Supply Unit (voltage controlled), 0-30 Volts, 0-5.28 Amps; I use it at 24Volts
After I gave you all the infos (I hope), here is the issue: when using the motor at higher PWM (from 45 to 100), no problems at all. When I’m turning to lower PWM levels (under 30), the Power Supply tells me than I’m going to Amp Limitation (I can set the maximum amps supplied by the PSU).
it’s quite strange: maximum ampere usage of the pump is 3.4 Amp, and I set the map amps at the PSU at 5.28Amps.
I think I’m missing something about MOSFET behaviour. I’m quite sure of that.