Let's Make Robots!

Solar Cell

Attracts FireFlies into your garden
Using a
This is robotic Firefly based on a picaxe 08 using UltraViolet leds as sensors. Flight School. Here you can see her Big Flattering Stereo eyes, they are simply … Read more

Charge Capacitor with Solar Panel

Is anyone aware of a simple circuit that will charge a capacitor with a solar panel (Small one from calculator) and then discharge to an LED via a transistor when the capacitor get's fully charged? The point is to make the LED flash. The frequency of the flashes would depend on ambient light conditions (less light, longer charge time). The closest thing I found is the circuit bellow. Would replacing the +12V with a solar panel still make it work (just take longer to charge)? Also what is the N.C. symbol at the transistors base ?(No Circuit or Normally Closed???)