Motor speed controllers are electronic devices that control motor speed. They carry specifications for drive type, product classification, electrical ratings, and operating parameters. Drive type describes the category of motor or system that is driven or controlled. Choices for alternating current (AC) products include induction motors, synchronous motors, pole number control drives, sensor-less vector drives, vector or feedback drives, and servos or brushless motors. Choices for direct current (DC) motors include brushed motors, brushless motors, and servomotors. Drive-type categories for stepper motors include unipolar stepper, bipolar stepper, permanent magnet stepper, variable reluctance stepper, and hybrid stepper. Full-step, half-step, mini-step and micro-step products are also available. Suppliers of motor speed controllers may also offer products for linear, voice coil, pneumatic, and hydraulic motors.   

There are four product classification specifications for motor speed controllers: number of axes or motors, rated power, resolution and application category. Computer-based products carry a fifth specification for bus type. Choices include advanced technology attachment (ATA), integrated drive electronics (IDE), enhanced IDE (EIDE), industry standard architecture (ISA), enhanced ISA (EISA), PC/104, peripheral component interconnect (PCI), PCI mezzanine card (PMC), and PCI extensions for instrumentation (PXI), and compact PCI (cPCI). VersaModule Eurocard (VMEbus) is a popular, 32-bit bus used in industrial, commercial and military applications. Versions include VME extensions for instrumentation (VXI) and multi-system extension interface (MXI). In terms of application categories, some motor speed controllers are described as multi-axis controllers, robotic motion controllers, or microcontroller-based. Others use pulse width modulation (PWM), digital signal processing (DSP), or variable speed drives.    

Motor speed controllers are electronic devices that control motor speed. They carry specifications for drive type, product classification, electrical ratings, and operating parameters. Drive type describes the category of motor or system that is driven or controlled. Choices for alternating current (AC) products include induction motors, synchronous motors, pole number control drives, sensor-less vector drives, vector or feedback drives, and servos or brushless motors. Choices for direct current (DC) motors include brushed motors, brushless motors, and servomotors. Drive-type categories for stepper motors include unipolar stepper, bipolar stepper, permanent magnet stepper, variable reluctance stepper, and hybrid stepper. Full-step, half-step, mini-step and micro-step products are also available. Suppliers of motor speed controllers may also offer products for linear, voice coil, pneumatic, and hydraulic motors.   

There are four product classification specifications for motor speed controllers: number of axes or motors, rated power, resolution and application category. Computer-based products carry a fifth specification for bus type. Choices include advanced technology attachment (ATA), integrated drive electronics (IDE), enhanced IDE (EIDE), industry standard architecture (ISA), enhanced ISA (EISA), PC/104, peripheral component interconnect (PCI), PCI mezzanine card (PMC), and PCI extensions for instrumentation (PXI), and compact PCI (cPCI). VersaModule Eurocard (VMEbus) is a popular, 32-bit bus used in industrial, commercial and military applications. Versions include VME extensions for instrumentation (VXI) and multi-system extension interface (MXI). In terms of application categories, some motor speed controllers are described as multi-axis controllers, robotic motion controllers, or microcontroller-based. Others use pulse width modulation (PWM), digital signal processing (DSP), or variable speed drives.    

Selecting motor speed controllers requires an analysis of both electrical specifications and operating parameters. Supply voltage (AC), supply voltage (DC), maximum output voltage, continuous output current, peak output current, AC input phase, and AC input frequency are important electrical specifications to consider. There are two choices for AC input phase: single-phase and three-phase. There are also three choices for AC input frequency: 50, 60, and 400 Hz. In terms of operating parameters, there are five main categories: setup and control, mode of operation, motor feedback, mounting style, and features. Setup and control is often achieved with a joystick, control panel, computer interface, disk, or wireless communication. Modes of operation include digital position feedback, analog feedback, velocity mode, and current (torque) mode. Hall effect, resolver, tachometer, incremental encoder, absolute encoder, analog position, sine and cosine are choices for motor feedback. Motor speed controllers with dynamic, injection, and regenerative braking are also available.