Thyristor & Power Control Circuits Unit 4 – SCR AC Control
Exercise 2 – Full-Wave Phase Control
EXERCISE OBJECTIVE
When you have completed this exercise, you will be able to describe full-wave phase control by
using a typical SCR ac power control circuit. You will verify your results with an oscilloscope.
EXERCISE DISCUSSION
- This circuit uses the SCR to control the full-wave bridge rectifier.
- When SCR (Q2) is conducting, a voltage appears across the load resistor (R8).
- Since CR3 is a full-wave rectifier, current flows through the load during both cycles of the ac
input voltage (Vac).