Product Description:

The BDU-15A servo drive is manufactured by Okuma and belongs to the BDU Servomotor Drives series. The unit converts a fixed DC supply into a variable AC output for brushless servo motors, allowing closed-loop positioning on machine tools and automated handling equipment. It forms the interface between the CNC’s motion commands and the mechanical load.

Internally, the drive maintains a DC link of 300 VDC; this level stores energy in the bus capacitors and is the reference from which the inverter stage synthesizes the three-phase output. As a DC-input, AC-output servo drive, the inverter uses AC PWM switching so the average voltage applied to the motor is modulated at high frequency, reducing torque ripple and acoustic noise. At peak shaft loading, the connected motor may draw up to 15 A, a rating that determines cable sizing and thermal design inside the cabinet. Motion commands enter through the Digital RCON interface, enabling the CNC controller to transmit position, velocity, and diagnostic data over a deterministic link. Mains power is supplied at 220 VAC across three input lines; this voltage is rectified to feed the DC bus and also supplies the +12, -12, and 5 VDC control rails. Diagnostic access is available through five check terminals that allow key voltages to be checked without disassembling the unit.

Protection thresholds are integrated so the drive disconnects when the bus exceeds 430 VDC, preventing semiconductor over-stress, or if it falls to 220 VDC, which avoids undervoltage misfires during regeneration. Position feedback is handled by an Absolute Position Encoder, allowing the controller to read the rotor angle immediately after power-on without homing cycles. The drive supervises 1 mechanical axis, and three incoming phases provide balanced power delivery. Additional front-panel indicators include seven DCPS LEDs and ten service LEDs, which simplify status checks without external instruments.