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 ...

In this flashing led lights circuit, the LDR or photoresistor is connected in such way that when the light intensity varies it will influence the flashing frequency and the brightness of the LEDs. T1, ...

The LDR circuit working: One terminal of LDR is connected to the base of the BC547 and other end of the LDR is connected to the collector of the transistor, and collector of the transistor is grounded ...