Hi, I recently purchased a couple of stepper motors listed as 1000rpm, 3A, 12-48V, 9kg.cm, 6 wire steppers. I'm new to steppers, but have been reading a lot. I was hoping to build a driver with minimum components and drive with an Arduino. As I understand it, I should be able to drive the stepper at it's rated current and voltage without needing a chopper circuit, but understand that I won't get the maximum possible torque.
When the motors arrived I found that they measure 1.7 ohms across each of the two windings and 1.1 ohms from the center tap to each end. My first question is, is this really a normal unipolar motor? Why is the restistance across the ful coil not exactly twice the half coil?
Second question, since the resistance is only 1.1 ohms, if I drive the coil at 12v then won't the current be about 12A and not 3A? There are no markings on the motor. Were the specs in the listing incorrect, or is my thinking?
I stupidly tied the 12v without thinking a melted a wire. Then I set the voltage to 3.3v and do see about 2.7A now. The circuit works ok this way, but I can only get 100rpms without dropping steps even with no load.
When the motors arrived I found that they measure 1.7 ohms across each of the two windings and 1.1 ohms from the center tap to each end. My first question is, is this really a normal unipolar motor? Why is the restistance across the ful coil not exactly twice the half coil?
Second question, since the resistance is only 1.1 ohms, if I drive the coil at 12v then won't the current be about 12A and not 3A? There are no markings on the motor. Were the specs in the listing incorrect, or is my thinking?
I stupidly tied the 12v without thinking a melted a wire. Then I set the voltage to 3.3v and do see about 2.7A now. The circuit works ok this way, but I can only get 100rpms without dropping steps even with no load.
