Top 12 Controllers

No person that works with motors will underestimate the efficacy of a motor controller. Choosing a motor controller can be a technical process, but following this guide will ease your worries, as it tells you everything you need to know about selecting a motor speed controller suited to your requirements.

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Controllers Buying Guide

Electronic motor controllers are devices that control the speed, torque and positioning of a motor. They work by receiving input for a particular speed, torque, or position and then controlling the supply of power to the motor to work up to the specified input variable. There are motor controllers of several types with various features, each with its own set of pros and cons.

Types of motor speed controllers

Motor controllers are of four types: AC, DC, stepper, and servomotor. The controllers are commonly integrated with the drive circuits and supply control signals to the drive. AC motor controllers are mainly used to control the speed of blowers, fans, pumps, etc. DC motor controllers are used primarily to control speed and torque for pumps, electric vehicles, and machine tools. Finally, Stepper motor controllers (also known as motor indexes) and servomotors control speed, position, and torque in robotics, micro-positioning, machine tools, and spindle drive systems, among many others. 

Brushed vs Brushless motors

Motors of one category cannot be used with controllers of another category. Hence, a brushed DC motor cannot have a brushless motor controller. Brushed DC motors are suited for extreme operating environments, can often be rebuilt, have low construction costs, and require an inexpensive and straightforward controller. On the other hand, brushless DC motors require less maintenance due to their lack of brushes, have higher speed range, output power and efficiency, have better thermal characteristics, and generate less noise. Brushed motors are primarily used in automobiles and household appliances, while brushless motors are used in computing, manufacturing, etc.

Characteristics of a motor controller

There are manly four parameters to consider when purchasing an electric motor controller. They are the number of motors or axes the device can control, rated power, resolution, and bus type.  The rated power is the maximum power that can be used with the motor. The number of bits (binary digits) required by the controller to characterise an analogue signal is termed the resolution. Finally, bus type transmits data both within and between computer systems and their controllers.

Features to look out for

Controllers with a status monitoring function look after some set parameters and alert the operator with an alarm in the event of over-voltage, over-current, over-speed, or any drastic temperature changes. Devices with auto-tuning or self-configuration will automatically adjust their settings according to the detected operating conditions. Brake output switches can control or activate an external brake.