Electronics-Lab.com Blog

Control the colour of a powerful LED light beam with a remote control, store the colours and recall them at will. [via]

With this thing I can control the colour of a bright light into many different colours using the three fundamentals colours : red green and blue. Adding them toghether with different intensity can yeld very great a range of colours from the visible spectrum.

A remote controlled power RGB LED mood light - [Link]

Here is an interesting LED binary clock by instructables user ElevenOf9. I really like the single sided PCB, and the way the LEDs are arranged. It just looks cool! [via]

This is the second revision of my PIC based LED binary clock. The original version was the first PIC project I attempted, it used a PIC16F84A to do both the timekeeping and control the display matrix, unfortunately it didn’t keep good enough time and gained about a minute every week.

LED Binary Clock – [Link]

Creating some blinky LED lights for Christmas has always been on my wish list. Last Christmas season I really started thinking about building something. My first thought was, each LED lamp could simply be connected to a pair of wires. The power to the LED lamps could be an AC signal that would sweep from a low frequency to a high frequency.

Designing a Multi Node LED PWM Lamp – [Link]

Thermal design can be a more significant determinant of total light output in high-brightness LED designs than the electrical design. LED lifetimes can decrease as temperatures rise, and at high enough temperatures, LED efficacy decreases. To ease the thermal design challenges, National’s new PowerWise® LM3424 LED driver features thermal foldback which reduces regulated current through the LEDs as the temperature increases.

LM3424 Thermal Foldback – Easy Thermal Control for LED Lighting - [Link]

There’s a dark stair well i traverse every night to get to my apartment. I modified a cheap tap-light to be [Tap-> stay on for 40 seconds, then shut off]. The mod takes all of 10 minutes to do, and is really useful if you don’t want to go back and shut it off.

Quick Modification to a Tap Light - [Link]

I came across a very nice article at tinkerlog.com  explaining why you need to use a current limiting resistor to power your leds. They write:

In this post I will try to show, why it’s a good idea to use a current limiting resistor for an LED. And when it’s safe to drive the LED without any resistor.

If you read about LEDs, you will notice that everyone tells you, that you need a current limiting resistor. But mostly they do not tell you why.

Driving an LED with or without a resistor - [Link]

LM3909 is a monolithic oscillator designed by National Semiconductor , to flash (LED) Light Emitting Diodes. Packaged in DIP 8 package LM3909 will operate  between -25 and 75 degree . LM3909  require to work only few components and can be used in many light electrical applications. LM3909 can be used in applications like : warning indicators powered by 1.4V to 200V, toys and novelties . This chip seems not in production right now, do you know any replacement IC? leave comment.

The main features of LM3909 are :

• operation over one year from one C size flashlight cell
• bright, high current LED pulse
• few  external components- low cost
• low voltage operation ( 1V to 5V )
• low current drain (under 0.5 mA )
• wide  temperature range

LM3909 Led flasher - [Link] + [PDF]

Acriche is the world’s first semiconductor light source that operates directly from AC power without a converter. This makes it suitable for many residential and commercial lighting applications where the main source of available power is AC. A design with Acriche product minimizes component count and board space. Acriche (pronounced ‘Ak rich) comes from the Greek “Acro” which means “the top” and the French “riche” meaning richness.

Acriche: High efficiency LED operates directly from AC power - [Link]

led.hypertriangle.com writes:

The design and fabrication of this LED based lighting system took approximately 6 months from start to finish. As you may have read already, the goal was to match the light output of a 32 watt T8 fluorescent lamp while using significantly less energy. This is an ambitious task because T8 fluorescent lamps are the more efficient flavour of this technology. The LED bulbs that were designed are intended to run on sealed lead-acid batteries which means they can accept an input voltage of anywhere from 10.5 V to 13.5 V. This input voltage was chosen to make the bulbs compatible with solar or wind energy systems. This means that if your home or building is operating on solar or wind energy, you can connect these bulbs directly to the batteries and bypass the inverter. This allows you to purchase a smaller inverter and requires you to have less solar panels (due to the energy loss when converting from 12 VDC to 120 VAC).

Fluorescent style LED tube lamp - [Link]