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 ...

Here is a light-operated light switch circuit built with solid state components that is used to operate a lamp. During darkness the resistance of LDR is in the MΩ range and so the triac does not ...

Llight operated switches are not new ideas, but neither are they the easiest items to purchase ready-made. Originally, this unit was built to switch on the author's outside Christmas lights when it ...