Hello,
I am using two Tic motor controllers for a test project. as part of the test, I need to measure the power consumption for each motor. I am using separate power supplies, both set at 24V and I was hoping to monitor the current on the power supplies. however, I find that the the Tic controller is drawing current even when the motor is not running and it changes very little (almost none) when the motor runs loaded.
I am hoping that there is a better way of measuring the power consumption for these controllers and any help is much appreciated.
Hello.
It is not clear from your post how you are monitoring the current now, but if you are interested in an alternate approach, you might consider one of our in-line current sensors.
It seems like you might be surprised by your current measurement results now, but the behavior sounds normal for a stepper motor. Unlike brushed DC motors, the current draw from a stepper motor is not affected by the load on the motor, and it will draw current when holding position(hence why it has holding torque) even if no other torques act on it . Instead, a stepper motor’s current draw from a bipolar stepper motor driver/controller, like the Tic, depends on the configured current limit (and how that compares to your supply voltage and the motor’s coil resistance) and microstepping.
Additionally, keep in mind that since the input voltage to the driver can be significantly higher than the coil voltage, the measured current on the power supply can be quite a bit lower than the coil current (the driver and coil basically act like a switching step-down power supply).
- Patrick
Thank you Patrick, this was very informative.
Patrick,
how would I use the sensors you linked with a stepper motor. would I need to use two of them and total the currents?
thank you,
