Choosing A Power Supply; Voltage; Current - NI ISM-7412 User Manual

Choosing a Power Supply

NI offers two power supplies for the NI ISM-7411/7412:
• NI PS-12 (24 V, 6.3 A)
• NI PS-13 (48 V, 6.7 A)

Voltage

Your motor can provide optimum performance between 24 and 48 volts DC. Choosing the
voltage depends on the performance needed and thermal performance. Higher voltages will give
higher speed performance but will cause the motor to operate at higher temperatures. Using
power supplies with voltage outputs that are near the drive maximum may reduce the operational
duty-cycle significantly. Refer to the charts in
performance at different power supply voltages.
If you choose an unregulated power supply, ensure the no-load voltage of the
Note
supply does not exceed 60 VDC.

Current

The power supply current required by the motor at various voltages is shown in the following
charts. The supply current flowing into the motor may be less than the motor phase current,
because the motor amplifier converts high voltages and low currents from the DC power supply
into the higher current and lower voltage required by the motor. Using a higher voltage power
supply will increase high speed torque, but will also increase motor heating.
The current draw is significantly different at higher speeds depending on the motor torque load.
Estimating your current needs may require a good analysis of the load the motor will encounter.
NI ISM-7411/7412 Integrated Stepper User Manual | © National Instruments | 5
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