Simple AC Switch (MEC136E)

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. The circuit shown in Figure 1 can be used to turn an ac load on and off.



Figure 1    Simple ac switch.
Figure 1 Simple ac switch.



Notice that the circuit conducts only the positive semicycles of the power supply voltage.

This means that approximately half of the total power is applied to the load. For low-power loads, it is possible to compensate for this loss of power in the load by connecting a large value capacitor in parallel.