Product Description:

Pacific Scientific’s SC724A-001-PM72012 belongs to the SC720 Command Controllers series and functions as a torque and velocity servo controller for brushless motor axes in automated machinery. Classified in the 720 Series product group, the module converts three-phase 240 Vac bus power into regulated DC and modulates that energy through an IGBT bridge. It closes the torque loop, executes ±10 V velocity commands, and presents resolver-derived feedback emulation while maintaining positioning accuracy within ±22 arcmin. This arrangement supports closed-loop axis control where stable speed response and accurate motion tracking are required.

The power section draws a maximum bus current of 18 Arms, charging bulk capacitors to a nominal bus voltage of 320 Vdc. Under continuous duty, the amplifier delivers 15 A of output current, corresponding to a sustained mechanical power of 4.5 kW. Current monitoring is simplified by the built-in 0.16 V/A scale factor, which provides a proportional analog signal for external meters or PLC inputs. Motor commutation relies on the resolver interface, yet the controller also produces a synthesized quadrature signal with an effective resolution of 1024 ppr for controls that expect incremental encoder feedback. That signal format can be used without adding a separate feedback conversion module. At this operating point, the drive can generate 43 lb-in of shaft torque without exceeding its thermal model.

For short acceleration bursts, the current limit rises to 30 A, allowing the motor to reach a peak mechanical output of 9 kW and develop 95 lb-in of transient torque. These peaks are supported while the shaft tracks a rated speed of 4000 rpm, giving motion systems the headroom required for rapid indexing or correction moves. Digital conversion of resolver data occurs at 12 bit resolution, supplying the servo loop with finer angle detail during high-demand events. The controller’s 40 lb enclosure houses the power stages and signal conditioning, so it can be panel-mounted without external heat sinks. Its integrated layout keeps the feedback and power electronics in one chassis, which helps conserve cabinet space.