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 ...

Before we get into how to wire and apply these relays, it's probably best to review what relays do and how they work. A relay is designed to allow a light-duty switch to control a high-current ...

This dark activated switch can trigger a relay to operate an AC lamp at Sunset. The lamp remains on till morning and then turns off. This eliminates the need of switching the Porch lamp or Backyard ...