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Stepper Motor System Basics

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Power Supplies

step101.pdf pdf  




The current capability is another key parameter in selecting an appropriate power supply. The current rating is determined by the choice of motor and the stepping mode you are planning to use it in. Full step mode, where both phases are on all the time at maximum current, requires more current than microstepping modes. Also, the current draw strongly depends on the voltage. The higher the voltage, the less current will be required from the power supply to achieve a given phase current in the windings of the motor.


Typically a power supply capable of delivering ½ or more of the peak phase current should be sufficient. For example, if you are using a motor with a maximum phase current of 4A per phase and assuming the drive is set to this maximum value, a power supply capable of delivering 2A or more will be adequate in most applications.


When connecting several drives / motors to one power supply, the current draw for all drives need to be added together to yield the requirement for the power supply.