Geiger Counter

This DIY Geiger counter clicks and flashes an LED each time it detects a radioactive particle. It works with most common Geiger–Müller tubes, and easily connects to radiation rate meters, data loggers, true random number generators, and the Radiation Network’s GeigerGraph software. Share your radiation readings with the whole world! Read more »

Wearable Light Organ

This simple, wearable circuit uses an operational amplifier (or “op-amp”) chip to convert sound into light. An LM324 op-amp and a transistor boost input from a mini condenser microphone to light a series of LEDs. Watch it blink to the beat of your favorite music. Check out more Weekend Projects. Read more »