Lighting LEDs from a single 1.5V cell poses a problem because their forward voltages are higher than the cell’s. The simplest way to light the LED is to use a step-up dc/dc converter. This Design Idea offers a simple and reliable alternative for applications in which low cost is of primary concern. The circuit in Figure 1 employs a classic astable oscillator, which transistors Q1 and Q2 form. The square-wave drive signal at Q2’s collector turns a PNP switching transistor, Q3, on and off. When Q3 turns on, it charges inductor L1, and, when it turns off, inductor L1 discharges its stored energy through the LED during flyback, allowing you to light any type or color of LED.
Astable multivibrator lights LED from a single cell - [Link]
TouchCounters are interactive electronic labels consisting of modular electronic devices with an integrated communication and sensing system. They are attached to physical storage containers in order for someone to get a better idea of what is inside these objects. The project also has a Java component that will relay a container’s status and contents to remote users over the Internet. I guess this proves that we don’t have any excuse left for not cleaning out our closets. [via]
TouchCounters: Interactive Electronic Labels – [Link]
Any fire is dangerous, especially around kids, burny melty pumpkins stink, and regular candles need to be replaced quite often. So I searched around for a project to copy, oddly enough I could not find one I liked, so I created one myself. My original proof of concept was on an arduino, but that is a bit pricey for a simple candle. Once I proved it would work, I found a way to do it cheap.
Flameless candle from an attiny13 – [Link]
Flickering LED Candle - [Link]
Tiny LED Jack-O’-Lantern – [Link]
Hawco introduces new linkable, low-profile LED strip lights that offer an economical alternative to incandescent and florescent lighting. Designated PLANETSAVER®, the LED strip lights are available in two versions: a 230 Volt AC module and a 12 Volt DC LED ultras low power (ULP) module. Both versions feature a versatile plug-and-play facility that enables multiple units to be connected in series to meet lighting requirements. The rugged PLANETSAVER LED Strip Lights significantly lower energy consumption and feature a long operating life of more than 50,000 hours, reducing maintenance costs. [via]
LED replacement for incandescent and fluorescent light bulbs – [Link]
I liked the tvbgone kit from Ladyada the first time i saw it but i never had the time to build it, until a week ago. But than i decided to build a more powerful one that could turn off TV’s from even greater distance. I came up with a design that consists of 48 IR LED’s and a ATmega8 that will send the signals to the LED’s.
Super TV-B-Gone - [Link]
Do you like the way Mac status led pulses like it is breathing? Then build your own with simple parts. Anybody who?s seen a G4 knows it. That power LED that fades in and out. Figured that’d make a sweet addition to a modded case, especially since it’s less then $3 in parts. Besides, why should them Mac people have all the fun?
Pulsing LED - [Link]
General Description of the following circuit. This circuit is based around HT2050 manufactured by HOLTEK semiconductors. It is a low cost, low-power C-MOS LSI designed for lamp and LED flash driver. It requires minimum external components.You can operate it with just two AAA cell or 3v Battery.Circuit has five flash outputs with 10mA drive capability that can implement random or sequence flashing function controlled by one option pin.It only requires one external resistor for typical application. It is very suitable for the use of the flash products such as disco glasses, disco hat, gift card, X’mas decoration and so forth.
5 Lamp / LED Flash Driver - [Link]
I’ve always liked all kinds of led displays and a rotating one is maybe one of the most interesting ones. I’ve been planning on building one for many years (actually I made one a couple of years ago, but it is was quite crappy). I finally got some good ideas on how I’ll make the first proper display and started to plan the schematics and the pcb with Eagle. You can see the finished ones below.
Rotating led display - [Link]