Product Description:

The digifas 7105-SPS is a servo amplifier manufactured by Kollmorgen and included in the DIGIFAS 7000 Servo Amplifiers series. It converts fixed-frequency three-phase mains power into regulated variable-frequency output for brushless servomotors used in positioning axes, packaging machinery, and pick-and-place systems. By closing the current loop inside the drive, it maintains precise torque control so the motion controller can command rapid acceleration without saturating the motor windings.

The current loop can respond at up to 1 kHz, so reference changes are tracked within one millisecond. Internal energy is stored on a 560 V DC bus charged by the rectifier stage, which helps reduce conductor current and copper loss. Pulse-width modulation operates at 8.33 kHz, which helps reduce audible noise and improve current resolution in low-inductance windings. For short bursts, the amplifier can supply 10 A rms, providing extra torque for acceleration or braking. Protection against contact with dust is indicated by the IP20 enclosure rating, so the unit must be installed inside a cabinet with forced airflow. The drive also has a minimum motor inductance of 8 mH, an input resistance of 20 kΩ on the command interface, and a power loss of 70 W at rated current.

The power section operates from a 3 x 400 V AC three-phase supply. Under continuous operation, it supports a connected load of 3 kVA and delivers a steady output of 5 A rms. An overvoltage threshold of 750 V disconnects the drive before excessive capacitor stress occurs, while the ballast circuit switches on at 720 V to dissipate excess energy. Voltage drop across the output stage is limited to 5 V, which helps improve efficiency. The motor must provide at least 8 mH of inductance for stable current regulation. Command and diagnostic signals are connected through a Mini Combicon 3.81 connector with twelve positions for 1.5 mm² conductors.