LDRs or Light Dependent Resistors are very useful especially in light/dark sensor circuits. Normally the resistance of an LDR is very high, sometimes as high as 1000 000 ohms, but when they are ...

The switch is a semiconductor relay S202DS2 and the oscillator is 4060. Sensor Light Switch Schematic. From the moment that T4 and T5 are opened, relay’s LED start to light and powers the lamp. As ...

This is a good project - building a whistle-activated light switch. Hold a note to turn it on, and whistle again to turn it off! Check out the website of Luke Allen, a US Navy officer, where he ...

He’s developed his own motion activated AC switching circuit to turn the lights on and off automatically. A motion sensor ensures that the lights are only on when there are people around to ...