Speed Control of Fan Motor using Diac and Triac

SPEED CONTROL OF A FAN MOTOR USING DIAC AND TRIAC.
EXPERIMENT – 15.
AIM: Construct and test speed control using DIAC and DIAC.
APPARATUS REQUIRED:
1. TRIAC BT136 = 1.
2. DIAC DS32 = 1.
3. Resistor 10k, Variable POT 220k = Each 1.
4. Polyester Capacitor 0.22 / 400V  = 1.
5. Fan or AC Motor = 11.
6. Connecting wire  = 10.
CIRCUIT DIAGRAM OF A FAN MOTOR USING DIAC AND TRIAC.

PROCEDURE:
• Choose the fan or any AC motor provided it should be rated below 100 watts.
• Take a bread board and connect the circuit as given in the below diagram.
• The firing circuit consists of resistor R1, potentiometer R2, capacitor C1 and a DIAC. Connect the one terminal of the DIAC to the voltage divider combination of resistors and capacitor as shown in figure.
• Consider the data sheet of TRIAC BT 136 for recognizing the terminals of TRIAC and to know the other detailed information. Connect MT1 terminal to the neutral while MT2 to one end of the AC motor or load. And connect the gate terminal to the other end of DIAC.
VIDEO:

• Connect the load fan between the Phase or Line terminal of the AC power supply and MT2 terminal of TRIAC
• By varying the pot (Variable Resistor)  R2, the rate at which capacitor is going to be charged get varied this means that if the resistance is less, the capacitor will charge at a faster rate so the earlier will be the conduction of TRIAC.
• As the potentiometer resistance gradually increases, the conduction angle of TRIAC will be reduced. Hence the average power across the load will be varied.
• Due to the bidirectional control capability of both TRIAC and DIAC, it is possible to control the firing angle of the TRIAC in both positive and negative peaks of the input.
RESULT:
Thus the speed control using DIAC & TRIAC circuit was constructed and tested with Fan.
LIST OF EXPERIMENTS:
1. VI Characteristics of PN Junction Diode & find cut-in-voltage. CLICK HERE

2. VI Characteristics of Zener Diode & find break down voltage

3. Regulation Characteristics of Half wave rectifier with filler and without fillers.

4. Regulation Characteristics of Full wave Rectifier with filler and without fillers.

4. Regulation Characteristics of Bridge Rectifier with fillers.

6. Input & Output Characteristics of CE Transistor & find input and output resistance.

7. Frequency Response of RC coupled amplifier and determine the 3-db bandwidth.

8. Characteristics of JFET and find its pinch off voltage.

9. Characteristics of UJT & find its Ip and Vv.

10. SCR Characteristics and find break over voltage

11. Characteristics of DIAC AND TRIAC

12. Positive and Biased Diode clipper and Clamper

13. Characteristics of LDR and Photo Diode

14. Astable Multi-vibrations using NE555 IC & vary the output Frequency.