Here is a great collection of touch switch circuits. A touch switch is an electronic device that enables us to control a circuit by simply touching a sensor. Simple touch switch circuit with 4011 – ...

Here are some DIY LDR switch circuits available on our website and the web. LDR switches are used to switch a relay or other device when light are present or absent. LDRs or Light Dependent Resistors ...

This circuit diagram joins a cell, a switch and two bulbs. Click on the next slide to see what the circuit might look like if you built it.