Get flash to fully experience Pearltrees
LED Parts LEDs come in all shapes and sizes, but the 3mm T-1 or 5mm T-1¾ are probably the most common. The die is an itty bitty cube of semiconductor, the composition of which determines the color of the light given off.
Here’s an inexpensive electronic circuit that you can build to put in your Jack-o’lantern. It provides power to drive a few LEDs at night, and automatically turns them off during the daytime. It’s a simple and automatic dark-detecting circuit that you can use to for your very own photosensitive pumpkin. Our pumpkin project is closely related to the minimalist dark-detecting LED circuit that we showed previously. In that project– basically an LED throwie with a sensor– a phototransistor controls a single LED.
LOOK at the top row of pins. The third from the right is marked “CK” or “Clock”. BOTH the resistor and capacitor go to this pin. It’s a bit of a tight fit, but not hard to make. If you wish, you can use wire wrap to connect this pin to one leg each of the resistor and the capacitor. Or you can use very fine tip needle nose pliers and carefully fold a wire from the resistor and the capacitor around this pin, and then solder.
1.5 Volt LED Flashers The LED flasher circuits below operate on a single 1.5 volt battery. The circuit on the upper right uses the popular LM3909 LED flasher IC and requires only a timing capacitor and LED. The top left circuit, designed by Andre De-Guerin illustrates using a 100uF capacitor to double the battery voltage to obtain 3 volts for the LED. Two sections of a 74HC04 hex inverter are used as a squarewave oscillator that establishes the flash rate while a third section is used as a buffer that charges the capacitor in series with a 470 ohm resistor while the buffer output is at +1.5 volts.
Hello everyone! After finding out about the Arduino I ordered one. And I don't think I've unplugged it from my computer since! Well I have done many small project and such so far, I'm finding a wealth of information all over the net.