Product Description:

The SC723A-001 is a servo controller produced by Pacific Scientific as part of the SC720 Command Controllers series. Designed for closed-loop motion systems, this controller executes torque and velocity regulation for brushless servomotors on automated lines, conveyors, and material-handling axes. It accepts a ±10 V speed command, converts resolver feedback into digital position data, and modulates three-phase power through high-frequency PWM for responsive motor control. That combination lets the controller respond quickly to command changes while keeping motor motion smooth at low speed and during transitions between operating states. Housed in a 16 lb panel-mounted enclosure, the unit helps consolidate drive electronics while supporting accurate coordination across multiple axes.

At the output stage, the drive can deliver a continuous phase current of 7.5 A, while short-term motion demands are supported by a peak current of 15 A. These operating levels correspond to a continuous mechanical power capability of 2.2 kW and a momentary ceiling of 4.5 kW during acceleration. Power devices switch at a carrier frequency of 20 kHz, which reduces audible noise and gives the current loop finer control of motor response. These limits set the thermal load, heat sink requirements, and overcurrent protection settings for matched servomotors. In practical use, the controller can support steady production motion as well as brief overload periods needed to move inertia, recover speed, or maintain tracking when the load changes suddenly.

On the supply side, a labeled bus current of 9 Arms feeds the internal capacitor bank, producing a DC link of 160 Vdc from a 120 Vac source or 320 Vdc from a 240 Vac source. Energy returned during deceleration is absorbed by a shunt regulator that handles 40 W continuously and up to 6 kW in peaks, which helps prevent overvoltage trips during aggressive braking. Position data is processed at 12-bit resolver resolution, and the built-in encoder emulator provides 1024 ppr signals for downstream PLC counters and other position-monitoring devices. The resolver interface and encoder emulation also let the controller work with control systems that expect conventional feedback signals, while commutation and regulation remain handled internally. Accuracy of ±22 arc-minutes, a velocity offset drift of 50 mV/°C, and a current monitor output of 0.32 V/A support consistent feedback handling and real-time load observation during long operating cycles.