[bing]

Actually we only need a single 555 to add that extra inverted pwm output, but since you have tons of 556 instead of 555 lol ... j/k , so here it is :



With this additional 556 ic, you got yourself two normal pwm ports, with this both will be enough for driving lotsa normal pwm fans , and the other one is the inverted pwm output that only serves those weirdos inverted pwm fans like your san ace.

Now you owe us all another video of this mutant controller driving mulitple mixed bag of pwm fans. ..lol