Full-Wave AC Switch I (MEC137E)

This article was written based on my book Robotics, Mechatronics and Artificial Intelligence (sold out) published in the United States. The described circuit can be used to turn on and off loads powered from the AC power grid. This block eliminates the inconvenience of Block 85 (loss of half of the power), as shown in Fig. 1.

 The full bridge in the input enables the operation of the SCR with both the negative and positive semicycles of the power supply voltage. The diodes must be rated for the voltage and current required by the load. The switch can be replaced by a sensor.



Figure 1    Full-wave ac switch I.
Figure 1 Full-wave ac switch I.



(*) Indicated to currents up to 1 A. For heavier loads use the 1N4004 and the 1N4007 for the 220/240 AC power grid.