Product Description:

The SPM-090-07 is a compact servo and stepper motor drive manufactured by Copley Controls for the Stepnet Compact Drives series. It receives command signals from a PLC or motion controller and produces a regulated, pulse-width-modulated output that powers a single axis in industrial automation equipment. By combining control electronics and power stages in a small footprint, the unit supports high-precision motion where cabinet space and wiring simplicity are important.

The drive accepts an analog velocity or torque reference of ±10 Vdc, allowing direct connection to conventional process controllers. During continuous operation, it can source up to 5 Adc to the motor phases, while transient demands are satisfied with a peak capability of 7 Adc for 1 s. Current is regulated by a DSP-based loop that updates at 16 kHz, so dynamic errors are suppressed quickly during load changes. The input supply must deliver 5.5 Adc on a steady-state basis and tolerate 7.7 Adc at startup or during acceleration; an auxiliary rail provides 500 mAdc to power the controller logic and field I/O. Minimum load inductance is specified to keep switching ripple within the magnetic limits of typical stepper and brushless windings. The onboard protection system disconnects the output if overcurrent or overtemperature thresholds are crossed.

For high-resolution feedback devices, the encoder port supports line rates up to 5 MHz and supplies 400 mAdc to power differential or single-ended sensors. Motor coils must present at least 200 µH of inductance, which prevents excessive di/dt when the drive switches at its 16 kHz PWM rate and the reflected ripple frequency of 32 kHz. An internal thermostat halts operation at 70 °C, protecting power semiconductors during elevated ambient conditions. Control electronics draw only 2.5 W from the auxiliary rail, so heat generation inside compact enclosures remains low while the velocity-position servo operates at 4 kHz for smooth profiling.