Blinking an LED with three resistors and a capacitor. Ok, ok… one of the resistors is a light-dependent resistor, but still. In reality, this is a classic relaxation oscillator. The capacitor ...

It is focusing the beam on a light dependent resistor to the right which looks almost like a red LED due to the intensity of the light. The simplicity of this circuit is fascinating. On the ...

Build a light-activated switch using LDR that lets you control home appliances using your mobile phone's torch.