Product Description:

The SC104 controller is a brushless servo drive produced by Pacific Scientific within the SC100 Brushless Servo Controllers series. It is intended to regulate permanent-magnet motors in automated machinery, converting fixed mains power into the variable voltage and current required for dynamic torque and speed control. By integrating commutation, current-loop control, and protective circuitry in one housing, the unit reduces panel wiring and simplifies axis integration.

Normal operation relies on a bus supply of 320 VDC that is synthesized from the three-phase, 47–63 Hz mains through a diode bridge and filter. Under continuous stall, the power section delivers 20 A of armature current, producing up to 6 kW of mechanical output while dissipating only 130 W as heat inside the chassis. The front end accepts an input of 230 VAC (+10%, −15%) on three phases and maintains an overall efficiency above 95%, so cabinet cooling requirements stay moderate. Ratings are valid between 0 °C and 50 °C, and operation outside this band requires derating or external cooling. A built-in shunt regulator absorbs regenerated energy continuously at 30 W and protects the bus against overvoltage transients. The power stage uses an IGBT bridge to balance current ripple with electromagnetic emissions.

For short bursts, the drive can supply 60 A of phase current for up to five seconds, translating into 17 kW of peak shaft power for rapid indexing or acceleration moves. During rapid deceleration, the shunt network can handle 15 kW for 300 ms, preventing the bus voltage from rising above safe limits. Command processing at a switching frequency of 5 kHz lets the current loop respond quickly to load changes and minimizes cogging during low-speed positioning. When equipment is stored, the controller tolerates −55 °C to 70 °C, allowing shipment or warehouse staging in unconditioned environments.