There is no need for external power supply because the light sensor switch is powered ... isolation of the switch block. Automatic light switch. Light sensitive switch. 4060 datasheet. Tags 4060 ...

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 ...

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 ...