CONTROL TECHNIQUES DIGITAX Servo Drive

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Digital Servo Drive for Brushless Motor – CONTROL TECHNIQUES DB420

The DB420 is a digital servo drive (“Digital Servo Drive”) belonging to the DIGITAX series by Control Techniques, designed for speed, position and torque control of brushless AC motors (permanent-magnet AC synchronous servomotors). It is documented as a component in CNC axis-control systems for machining centres, transfer machines and high-precision industrial automation. The DB420 receives the reference from the CNC controller and drives the servo motor via a high-switching-frequency three-phase PWM output; it internally manages the current (torque) and speed loops, with feedback from an incremental encoder or resolver. The “DB” designation identifies the brushless family within the DIGITAX series; “420” refers to the current/voltage rating. No distinct alternative part number is known other than the main code.

The digital servo drive is the electronic controller that translates CNC commands into precise current delivered to the axis motor: it maintains position and speed with sub-millisecond accuracy, ensuring dimensional repeatability of the machined workpiece. If the DB420 fails, the controlled axis is completely locked or uncontrollable; the machine triggers an alarm and cannot produce, with immediate impact on productivity and a potential risk of collision.

Control Techniques is a British manufacturer founded in the 1970s, a world leader in the design of AC drives, servo drives and motion control systems. The company was acquired by Emerson Electric in 2004 and subsequently by Nidec Corporation in 2017, continuing to operate under its own brand. The original generations of the DIGITAX product line (prior to the ST series) are legacy / discontinued: available exclusively as used, surplus or through specialist repair.

Main Technical Specifications