Yes I am pretty much facing a wall with power filtering. Problem is switching Hight current effects everything attached to that line....well it does on my power supply. If I had 2 ccts at 3A and another 2 and .5A...a heap of switching inrush!
I have some high current chokes from jaycar I was going to put in line & fiddle...some day!
Iceman is going to put my ccts on so you can see where I'm at, unless you want me to send you my eagle files now?
Another issue is FET on rds. I pretty much faced pdip (package power dissipation) problems when trying many FETs with .117 milli ohms rds (or so) at 3.5A. Each TO220 FET package can dissipate around 2.5W (Max) and rds on rises with I draw & pdip case increase.
So I turned to very low on rds fets....020milli ohms (IRF4905)! My ccts were designed with these low rds FETs..less pdip issues. But ATM but I am greedily eyeing some new generation automotive intelligent power switch FETs that have I fold-back... like the
IR1334 or IR3316. They are designed to run from 12V and have current fold back by using a resistor and/or even monitoring with something like an AVR.
I looked up commercial dew heaters & settled on a 3A per stage max output (with a little head room). Any more is for the big boys!
But I got to say I love your work.