Thyristor & Power Control Circuits Unit 6 – TRIAC Devices
Exercise 2 – The Triac Triggering Modes
EXERCISE OBJECTIVE
When you have completed this exercise, you will be able to demonstrate the four triggering
modes of a triac by using dc measurements. You will verify your results with an oscilloscope.
DISCUSSION
- A triac has four triggering modes.
- Mode I requires a positive gate signal when MT2 is positive with respect to MT1.
- Mode II requires a negative gate signal when MT2 is positive with respect to MT1.
- Mode III requires a positive gate signal when MT2 is negative with respect to MT1.
- Mode IV requires a negative gate signal when MT2 is negative with respect to MT1.