CONTROL TECHNIQUES Servo Drive

---

DC Motor Drive – Control Techniques DB 420 NP

The DB 420 NP is a DC motor drive (“DC Motor Drive”) manufactured by Control Techniques, belonging to the DB series of the Welsh manufacturer’s industrial drive range. The part number identifies a combined control and power unit for DC motors intended for industrial motion control applications; the NP designation denotes a specific constructional variant (typically “Non-Plug-in” or a configuration without a removable optional module). The drive manages the speed and torque regulation loops, interfacing with the CNC system’s control bus and with the motor’s tachogenerator or encoder feedback. The product is documented on CNC machine tools, automated production lines and numerical control systems using DC motors for axis or spindle drives.

The DC drive is the core of the motor control system: it receives the speed or torque reference from the numerical controller, regulates voltage and current to the motor armature and closes the feedback loop to deliver the required motion profile with precision and stability. A drive failure renders the controlled motor completely unmanageable, causing immediate process stoppage and a real risk of mechanical damage to moving parts; availability of a replacement unit is therefore critical to limiting unplanned machine downtime.

Control Techniques, founded in 1961 in Newtown (Wales, UK), is one of the world’s leading manufacturers of variable-speed drives for AC and DC motors, servo drives and motion control systems (Mentor, Unidrive, Commander, Digitax, Epsilon families). Acquired by Emerson Electric in 1992 and subsequently by Nidec Corporation in 2017, it continues to operate as an independent brand within the group. Products in the DB series are legacy / discontinued: available only as used, surplus or through specialist repair.

Main Technical Specifications