Skip to main content
blog | How Does a Servo Drive Work? |
|
2 minute read

A servo drive is an electronic device that is part of a closed loop system, producing current and voltage to rotate a servo motor. The closed loop system includes the servo drive, servo motor and feedback device, and is commanded from an analog or digital signal.

Servo drives are available in various voltage and current ratings and may provide position, velocity, and/or torque control. A wide range of servo motor types are controlled using servo drives, including AC, DC , brushed, brushless, rotary, or linear motors. The feedback device can be a potentiometer, Hall effects, tachometer, resolver, encoder, linear transducer, or any other sensor as appropriate. The servo drive powers the motor and compares the feedback data and command reference to verify that the servo motor is operating as commanded. The command signal is supplied from a variety of sources, most commonly from a PLC, CNC, or motion controller.

Breaking down a servo drive further reveals two major elements common in all servo drives – the power stage and servo loops. The drive power stage begins with input power from an AC or DC source and utilizes transistors in an H bridge configuration to deliver power to the servo motor. The transistors act as switches to facilitate voltage and current flow though the servo motor in either direction, providing forward or reverse motion.

The servo loops provide proportional control of the motor based on an input command signal. A simple servo drive may contain a single servo loop to control torque. More advanced servo drives add a velocity loop and may also contain a position loop. In a complete servo drive system, a digital signal provided by a motion controller will command a desired motion profile utilizing all three servo loops tuned for optimum performance. Each loop signals the subsequent loop and monitors the appropriate feedback elements to make real time corrections to match the commanded parameters.

Servo drives are available as ASIC chips where an electronic design engineer may integrate into a customized control platform, or as ready to connect “box” built units. In addition, servo drives are available integrated into motion controllers with ample I/O and safety elements in a single package.

Know your current and voltage requirements for a drive? Enter your specifications to search and compare our products, identifying what best fits your needs with our Product Selectors tool.

Consult an Expert

AKD Servo Drive

AKD® Series is a proven perfomer, supporting the largest customer installed base, and offers:

  • Industry leading motion control loops
  • Extensive motor feedback and drive fieldbus support including EtherCAT, EtherNet/IP, Profinet RT, etc.
  • Plug-and-play with Kollmorgen motors
  • WorkBench GUI, acclaimed for customer experience and usability
Learn More

AKD2G Servo Drive

Born from a rich AKD heritage, AKD2G is the latest servo drive technology adding:

  • Dual-axis technology for additional space savings
  • Built-in functional safety options via SafeMotion Monitor (including FSoE)
  • Color Graphic Display
  • Optimized for single-cable power and feedback
Learn More

Engineer the Exceptional

Learn how to engineer exceptional machines, robots and vehicles with the highest-performing, most reliable motors, drives, automation solutions and more.

Learn More

Related Resources

AKD2G Mentor Sessions: Advanced Configuration for AKD2G Dual Axis

AKD2G Mentor Sessions: Advanced Configuration for AKD2G Dual Axis >

Building from the AKD2G Quick Setup Guide, this session reviews special considerations for the dual-axis AKD2G drive. Controlling two axes in one drive provides a unique opportunity for triggering inputs, tuning, troubleshooting, and capturing data…
AKD2G Mentor Sessions: AKD2G Quick Setup Guide

AKD2G Mentor Sessions: AKD2G Quick Setup Guide >

Need to get up and running with your new 2G system? It starts with the AKD2G Workbench software. This session will give you the fundamentals you need to create motion quickly, build confidence, and accelerate your productivity.
Functional Safety 101 White Paper

Functional Safety 101: The What, Why and How >

Mandates and regulations aside, more customers are demanding functional safety. But no two applications are exactly the same, and there isn’t a one-size-fits-all solution. This whitepaper reveals how equipment manufacturers can stay up to speed.
Kollmorgen helps packaging automation solutions provider meet the need for on-demand “right-sized” packaging

Kollmorgen helps packaging automation solutions provider meet the need for on-demand “right-sized” packaging >

Kollmorgen's expertise in motion control components for packaging machinery helped Packsize tackle demanding challenges to create game-changing packaging automation solutions.

Adjusting Standard Motion Profiles to Optimize Operating Speed and Time >

Adjusting Standard Motion Profiles to Optimize Operating Speed and Time: Learn more about simple profile adjustments that can preserve motion, move time and provide memorable profiles.​​​​

Accelerating the Development of Next-Generation Prostheses and Exoskeletons >

Learn how Kollmorgen servo technology is helping OEMs accelerate the design of next-generation prostheses and exoskeletons.
Direct Drive Technology Increases the Speed and Quality of Electric Vehicle Lithium-Ion Battery Production

Direct Drive Technology Increases the Speed and Quality of Electric Vehicle Lithium-Ion Battery Production  >

One important stage in manufacturing lithium-ion batteries for electric vehicles is seal-welding the positive-terminal top cap to the battery shell. Laser welding is the ideal technology for this purpose, but it requires precise motion, speed and…
Ground satellite 

AKD2G 24A Data Sheet >

Kollmorgen’s new AKD2G 24A servo drive delivers 3x the continuous current capacity and offers a rich feature set for simple integration in complex applications. 
Kollmorgen White Paper, Monitoring and controlling brakes through on-drive functional safety technology

Monitoring and controlling brakes through on-drive functional safety technology >

How can you ensure the safety of vertical loads while complying with ISO 13849-1? On-drive safety functions offer a no-compromise way to simplify brake testing.