In a nut shell, I am building a custom controller for controlling upto two PWM devices with phase correction, manual speed ctrl adjust, and laser activity monitor function. I'll be posting my PCB artwork, schematics, and code as I build tune and finish them. The basic operation works like this, my LASER ETCHER that is getting closer to finished needs a custom controller to drive the speed of both the dual 7k RPM 120mm fans (both outputs) and a medical diaphragm BLDC based air VAC and pump C183-22-01. The fans are for pulling out the smoke and floating ash. The pump is for blowing the smoke away from the work area and clearing the work area for a better cut. The fans can move upto 250CFM each, the pump is capable of upto 5L/min. 5L/min pushed though a small tip is very powerful. If there is no laser activity for 5-10 seconds depending on the final design, the PWM devices will follow a preset action of turning off or running at low power. When signal is detected or a manual on switch is is chosen. The PWM devices will read the POT settings and operate as set while constantly monitoring the input laser signal for a change of function based on a timer. If I'm cutting paper or very thin materials they could get blown away. there for speed control is a must. My design uses an ATTINY85, 2 POTS, one input from laser and two outputs to the PWM pins of the fans in parallel, and the single compressor. If the fan or compressor pots are adjusted the devices will run at that adjusted speed for 5-10 seconds and then follow the state of the laser signal input. If there is no laser signal present and or if a manual switch is not on. Then the fans will drop to a pre-set minimum speed/PWM and the compressor will shut off. The signal pin could have custom firmware written to read a serial signal rather to have software control over the devices. But for now I'm leaving the system simple. Schematic and pcb may not be complete as of this posting. I'll post final versions when done and tested and source files.
Attachment 462976 Attachment 462978