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AC MOTOR SPEED CONTROL USING TRIAC
When we are furnishing a home, light is everything. The light level in a room dictates what we can and cannot do and it has a huge effect on how we feel.
The problem is that people need to use some rooms for multiple purposes, and these different functions call for varying amounts of light. The dimmer switch is a handy electrical component that allows the user to adjust light levels from nearly dark to fully lit by simply turning a knob or sliding a lever.
Early dimmer switches were very efficient but the problem with them is using a lot of energy to heat the resistor, which does not help to light up the room but still costs a lot. In addition to be being inefficient, these switches tend to be cumbersome and potentially dangerous, since the variable resistor releases a substantial amount of heat.
Thus the only solution to vary the intensity of light even in small steps or vary the speed of an AC motor is by using a TRIAC. The dimmer switch rapidly turns a light circuit on and off to reduce the energy flowing to a light switch. The central element in this switching circuit is a triode alternating current switch or TRIAC.
The speed of AC motor can be varied rapidly on and off by TRIAC. The main advantage of using a TRIAC to vary the speed of an AC motor is the TRIAC reduces the energy flow to the motor and TRIAC works very well for alternating currents. The speed of the motor can be seen on LCD display.
This project uses regulated 5V, 500mA power supply. 7805 three terminal voltage regulator is used for voltage regulation. Bridge type full wave rectifier is used to rectify the ac out put of secondary of 230/12V step down transformer.