Product Description:

The STX-115-07 is a compact digital drive module manufactured by Copley Controls for the Stepnet Compact Drives series. Designed for panel mounting in multi-axis assemblies, the unit supplies closed-loop power to hybrid stepper and brushless servo motors that move loads in automated pick-and-place cells, indexing tables, and small conveyor systems. By translating analog or pulse motion commands into high-frequency pulse-width-modulated phase currents, it functions as the power interface between the motion controller and the motor.

The drive delivers a continuous motor current of 5 Adc, which is the thermal ceiling for steady operation. For acceleration or disturbance rejection, it supplies up to 7 Adc for a maximum of 1 second before returning to the continuous level. A fast control loop updating at 15 kHz regulates that current, and the switching stage operates at 30 kHz so radiated noise stays above the audible band. Brake coils can be energized directly with 1 Adc from the integrated brake output, and excess kinetic energy is diverted to the regenerative circuit rated for 80 W. The module draws 8 Arms under full load, and its design requires motor windings to present at least 200 µH per phase to maintain current ripple within limits. The minimum pulse width is 220 ns, which is the narrowest controllable duty cycle at the selected carrier frequency.

The analog interface presents 5 kΩ of input impedance and converts references with a 12-bit A/D, giving 4096 discrete levels for torque or velocity commands. Pulse position control is equally responsive: the step input accepts edges to 1.5 MHz, while the internal trajectory planners close velocity and position loops at 3 kHz. Encoder signals are captured at rates to 20 Mcount/s, preventing missed counts on high-speed axes. When DC bus voltage rises to 200 Vdc, an overvoltage trip disconnects the drive and transfers energy to the shunt so downstream electronics are protected.