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 »
Charge up your USB devices with the power of the sun. By adding a small solar panel and two diodes to a standard USB cable, you can plug that cable into USB devices needing a recharge. It’s so easy. Let’s get started making a solar USB charger. Video shows the... Read more »
Using this simple technique, you can etch a design into a thin pane of clear plastic sheeting, then enclose the edges of the plastic with reflective tape and embed a battery-powered LED. The resulting design appears backlit and hovering in mid-air, with a laser-like textured glow that photographs cannot do... Read more »
