Light Dependent Resistor Circuits (LDR Circuits)

This circuit will play a tune when light strikes a light dependent resistor, such as when a music box lid is opened.

The Traffic Lights circuit performs actions just like those of a real traffic light system, switching between red, amber & green.

The most popular use for this kit is to make you own night-light. It can also be used to switch just about any appliance on or off in light or darkness. Light sensitivity is adjustable over quite a range. The relay can handle up to 10 Amps at 110VAC. Oper

Three relay-based electronic switching circuits that switch according to light levels.

Versatile light organ based on PIC microcontroller.

Complete instructions and circuit diagram for a Geiger counter meter device, which will allow you to measure radiation levels.

Introduces the Optocoupler-triac MOC3010. Complete electrical isolation between input audio signal (low voltage circuit) and output light modulation. Operates from 100 VAC line. Audio input via 3.5mm jack.

A sensitive photo Darlington transistor is used with a CMOS nand gate. The circuit detects light and triggers a siren. You could add your own triac or relay and switch practically anything. The kit uses the MEL12 Darlington super alpha phototransistor, ty

A stronger, Mecha-Medusa is a walking robot that operates with the aid of a sound sensor. Clap hands or snap fingers to command this robot to start walking on four legs. Stops automatically after a preset time. Ideal for the hobbyist or budding scientist.

Circuits that operate just like the real gameshows, where a light shows up for the first contestant to hit their answer button.

This super cool circuit behaves as a clapper-switch. You clap and the circuit turns on. Clap and it turns off. Great as a light clap switch.