I have several PMDC motors. I want to control the speed and mount them on my machine tools. (horiz. mill, desk top vert. mill, drill press) I have taken a first step. I have a bridge rectifier. (200v 35 amps) And I have a cap. (1500 mf 20% 200v) I can run the motors directly from these, but I need speed control. So as I understand it, I need some SCR's to switch the current off and on, and some type of feed back loop to control the duration of the pulses. Is there more to this PWM. Can I do it relatively simple, or do I really need lots more components to do it safely for me and my motors?
I am an avid learner, feeling my way through this. The above note may make me sound smarter than I am. My latest score is an old treadmill (working) with an m60 board. I have the motor and necessary related stuff off the TM and it still runs. I also wisely saved the schematic from the soft plastic under belly. And I think I will be fine putting this on a machine. But I still have 2 bigger, better, newer PMDC motors. The digital electronics on them was thick and heavy.
So. What does the big transformer looking thing do on the old one? I know it's called a choke. And my understanding is it somehow protects the delicate circuits from EMF back force from the generator effect of the PMDC motor when it's winding down. How are the curcuits protected in the newer digital TM's?