Speed Control Basics: VFD or Triac for AC Induction Motors?

When a voltage is applied to an AC induction motor, it runs at a certain speed.  Variable speed requirements for AC induction motors are typically fulfilled by a 3-phase motor and an inverter or VFD.  This blog post also introduces another option.

Single Phase Variable Frequency Drive VFD Circuit

Triac Universal Motor Speed Control Circuit Design Basics - Technical Articles

Why you don't need a variable-speed drive to change a fan's speed

Why can't we use SCR voltage regulator speed controller instead of VFD to control the speed of an AC motor? - Quora

SINGLE PHASE AC MOTOR SPEED CONTROL USING ARDUINO AND LAMP / BULB DIMMER USING ARDUINO WITH MOSFET

Single Phase Induction Motor Speed Control

Ac motor closedloo[p

AC Motor Speed Control

How to control the speed of an AC motor - Quora