EEE-454, Power Electronics Laboratory

Experiment 1

Switching Mechanism of Unidirectional Power Switches

Part 05


5. TRIAC AS A Switch:


EQUIPMENT:

  1. TRIAC - [Model: BT 136].
  2. Resistor - [1K].
  3. Ceramic Resistor - [220Ω]
  4. Power Supply - [10V].                                
  5. Connecting Wire.
  6. LED.
  7. Multimeter.
  8. Trainer Board.
  9. Variable DC Power Supply.


CIRCUIT DIAGRAM:


Fig. TRIAC as a switch.


Measured the voltage between M2 and M1 instead of VAK for both circuits.


DATA TABLE:


Forward Bias

Reverse Bias

VGG

Vm2m1

VGG

Vm2m1

0.3 V

9.81 V

0.3 V

9.8 V

1 V

9.81 V

2.9 V

9.77 V

1.5 V

9.81 V

5.1 V

9.62 V

1.8 V

9.81 V

7.2 V

9.5 V

1.9 V

0.786 V

8.1 V

9.47 V

3 V

0.786 V

10 V

0.52 V

4.3 V

0.786 V

11.5

0.76 V

 

The TRIAC turns on near about 15V so need to increase it more unlike MOSFET and SCR which turn on at around 0 to 10V.



PRACTICAL WORK:




DISCUSSION: This lab is related to how TRIAC works as a switch. We can use a TRIAC as a switch. By using a TRIAC as a switch, we can automate the process of switching or switching on or off the load remotely operated instead of using an electromechanical switch that is operated by hand. While doing this experiment, we follow all the rules of the laboratory. First of all, we connect all equipment by following a circuit diagram. Then we connect all the equipment with the AC supply for our experiment. TRIACS are electronic components that are widely used in AC power control applications. They are able to switch high voltages and high levels of current, and over both parts of an AC waveform. This makes TRIACS circuits ideal for use in a variety of applications where power switching is needed. One particular use of TRIACS circuits is in light dimmers for domestic lighting, and they are also used in many other power control situations including motor control and electronic switches. As a result of their performance, TRIACS tend to be used for low to medium power electronic switching applications, leaving thyristors to be used for the very heat duty AC power switching applications. We take all the values perfectly and put them on the table. We are very careful to take the value of voltages and currents. Sometimes multimeter was not capable to read the short-range value of current. So, we take an effective ammeter to measure the short range of the current value. Finally, we disconnect all the connections carefully and return the equipment to the lab assistant.

 

CONCLUSION: Among the switching devices, the current controlled device is the BJT, SCR, and TRIAC. The MOSFET is a voltage-controlled device. Using these devices circuits can be controlled according to the necessity of controlling (voltage or current).

 


PART - 04 CLICK HERE