Wawa:
You think it's wise to reduce power to the whole circuit, instead of only the solenoid.
Leo..
I'm reducing the power only to the solenoid, the whole circuit will use the main power souce.
MorganS:
Trying to current-limit a PWM power circuit is doomed to failure.Use a high-side driver with current feedback. I really like the BTS5012 for 12-15V systems and the BTT6010 for 24-28V. Those chips are much more than you need and hence almost bullet-proof. There are others in the family that may be more appropriate for just 2A.
With an appropriate RC filter on the feedback pin, your Arduino can control the current in the solenoid very accurately.
I checked the datasheet for the BTS5012 and if I understand it correctly, it offers a proportional output to read the current values. I do not know if this solution would be better than mine. Moreover, I should change the design of my board to use another driver and I would like to avoid to change it since the board is working very well with the FQP30N06L.
Why do you think the MAX17525 would be a bad idea? what are its side effects?