Hello, I am a novice in search of some pointers. (gee there is a new one!) I am attempting to control a stepper with the arduino. I have read all the tutorials on arduino.cc and elsewhere around the web. They all seem to agree that you should not run much more than a led from the arduino's power source. Ok, got it, I built a 5v regulated power supply that can supply 500ma and works great powering the 7474 d-flip-flop circuit that controls the stepping sequence.
I am planing on having the outputs from the control circuit flip some transistors to power the coils of my stepper. The steppers I have are:
Oriental Motor PK245-01AA Current per phase: 1.2 (Unipolar), .85 (Bipolar) Resistance per phase: 3.3 (Unipolar), 6.6 (Bipolar) Voltage: 4, (Unipolar), 5.6 (Bipolar)
The questions I have are, what do I need to do to power this thing? :-) Is the current rating on the stepper a max rating, ie Can I supply it less? Or is the motor going to draw that through the circuit and therefor the OTHER components must be able to handle this amount? (told ya I was a Novice) Also how do I take in account for the internal resistance, I understand V=IR, but not how to apply it to a motor.
If I need to supply the motor 'at least' the current rating, does anyone have a suggestion how to supply the correct amount? The small power supply I built is based off of the 7805 chip that even with heat sinking is only suppose to put out 900ma -1000ma, which sounds like cutting it a bit to close to me.
Part number answers would be helpful, but how you came up with the decision would be more helpful. I appreciate any help that the community can give.