I have been experimenting with the DRV8811 EVM board driving a Applied Motion HT17-275 Stepper Motor. I am looking for guidance on how to get the maximum torque out of the stepper motor. Right now, I have the motor connected to the evaluation board in a Bipolar Series configuration. My application is not complex--I need to run the stepper motor in both directions at a constant "slow" speed (I don't understand the acceleration/deceleration details). The speed is not critical (now at approx 2 revolutions/sec) I am using a step rate of 700 Hz. I have found through experimentation that this works best. Is there a phone number for TI tech support so I can brainstorm with someone about how to configure this chip? I am using a motor voltage of 12 VDC and my power supply can deliver about 500mA before the voltage starts to drop below 12 VDC. I would like to be able to get a bit more torque out of the motor without having to increase the size (VA rating) of the power supply (right now, I can stall the motor but if I use a supply rated at 12 VDC @ 1 amp, I get plenty of torque and the motor does not stall. operation is not continuous--say 45 seconds of operation followed by several minutes of rest.
Can someone help? What are best settings for DRV8811 parameters (e.g. Pulses Per Second, Current Control, Decay Control, Accel Rate, Time Base, etc.) to get max torque from a minimum 12 VDC supply?
Thanks!!
Mike