It is estimated that 40% to 60% of the ac motor applications would benefit from some form of closed-loop, smart speed control.

The OMDC-MD Series programmable dc speed control features digital closedloop feedback and LED display for dc motors rated to 2 hp. The control features adjustable minimum/maximum speeds ...

Traditionally, DC motors have been used in precise speed control applications because of their ability to provide acceleration and deceleration from a dead stop position to full speed fairly easily.

INTRODUCTION The thyristor d.c. drive remains an important speed-controlled industrial drive, especially where the higher maintenance cost associated with the d.c. motor brushes (c.f. induction motor) ...

A three-phase brushless DC motor predriver IC from Toshiba employs a sine-wave drive method that does not use Hall sensor control. The TC78B011FTG predriver is intended for high-speed motors, ...

In this case, they’re being used to create a basic PWM motor controller. The trick is to set the 555 up in astable mode, and use diodes and a potentiometer in the charge/discharge loop.

Toshiba: A three-phase brushless motor driver IC "TC78B025FTG" with a rotation speed control (closed loop control) function for small fans. (Photo: Business Wire) ...

Toshiba: a three-phase brushless motor control pre-driver IC “TC78B009FTG” for high-speed fans used in servers and cordless vacuum cleaners. (Photo: Business Wire) Full Size Small Preview ...

[Misan] has the solution to this: closed loop control of DC motors for a 3D printer. Most printer firmwares use an open loop control system for moving their motors around.