I recently started a CNC project as a way of learning something new about electronics, computer programing, etc.
Currently I have a 2 stepper controller using 2 mc3479 chips, and after some extensive research, I followed suite and used the power supply in my PC to make everything work. However, this leads me to my questions, more for my own understanding then anything.
First I tried to use a cheap 12v wall "brick" that I had laying around from some device that I no longer own. When using this, my steppers "giggled" even before plugging the parallel cable into the computer.
Next I tried my huge Pyramid Regulated Power Supply (Model PS-12KX) figuring more amps the better. Well, the steppers didn't "giggle" but they constantly rotated in one direction, again even before plugging the parallel cable into the computer.
Then finally, I ran some leads off the 12v lines from the computer's power supply and all is working as expected.
My question is why? What is different about the computer's power supply's power output? I'm assuming it is cleaner. How does one go about "fixing" one of these other two power supplies so they can work?
Any information will be greatly appreciated.
Thanks in advance,
Jeremy