by Abhijeet Deshpande:
Properly maintained rechargeable batteries can provide good service and long life. Maintenance involves regular monitoring of battery voltage. The circuit in Figure 1 works in most rechargeable batteries. It comprises a reference LED, LEDREF, which operates at a constant current of 1 mA and provides reference light of constant intensity regardless of battery voltage. It accomplishes this task by connecting resistor R1 in series with the diode. Therefore, even if the battery voltage changes from a charged state to a discharged state, the change in current is only 10%. Thus, the intensity of LEDREF remains constant for a battery state from a fully charged state to a fully discharged state.
Simple battery-status indicator uses two LEDs - [Link]
Aurora 48 is a compact and thin profile full-color LED sequencer. It’s built entirely with surface mount components, so the profile is nice and clean.
Aurora 48 – 48 RGB LED Sequencer - [Link]
Ivan Creations made this ReCoMonB (Real Computer Monitoring Block) and wrote a detailed explanation on his blog describing the build:
I managed to de-virtualize the CPU/MEM/HDD/NET stats and now I have them physically represented on my desk. The device that does that is named ReCoMonB – Real Computer Monitoring Block. I have also made the device driverless and working on Liunx and Windows.
ReCoMonB – Real Computer Monitoring Block - [Link]
DanNixon @ instructables.com writes:
I just happened to see some large strips of LED lighting when I was picking up some parts at Maplin which were on sale (if I remember correct they were around £12 per approx. 2m strip) however the controller/driver was still around £40, so I thought I would just build a better one myself.
I wanted it to be a web enabled controller as there are a lot of cool things that can be done with a device once it is accessible over HTTP, and I am working on a home automation server project so it would be good to have some devices which I can test this with.
Arduino Web Enabled RGB Lighting - [Link]
Professor John A. Rodgers has previously taught us what the future has in store by way of flexible, stampable microelectronics that adhere to the surface of human skin. As revolutionary as those devices can be – providing critical health-related information from real-time physiological monitoring of the human body – they are limited in their ability to penetrate the depth of human tissue for an even greater understanding. A recent study by Rodgers and his team from UIUC alongside Professor Michael R. Bruchas of Washington University has found a unique solution to the tissue issue – injectable LEDs that can stimulate and monitor brain activity.
Studying the brain with micro-injectable LEDs - [Link]
No-name GU10 LED lamp teardown @ kuzyatech.com
In the usual Kuzyatech fashion, when something breaks, we must take it apart. Today, one of the ”early adopter” GU10 style LED lamps decided to fail mechanically.
No-name GU10 LED lamp teardown - [Link]
Write messages and show animations on this palm-sized heart-shaped LED display. Works seamlessly with Arduino, and requires only three pins to control. Want a heart matrix of your very own? You can buy this as DIY kit.
Heart Matrix display - [Link]
by Publitek European Editors:
With the proliferation of high-brightness LEDs designed to provide replacement lamps for commercial and domestic lighting there comes an equal, if not greater, proliferation of power supply solutions. With hundreds of products from dozens of manufacturers, it becomes a question of how to make sense of all the permutations of input / output voltages and output current / power ratings, to say nothing of the mechanical dimensions / termination types and the many other features for dimming, remote control, and circuit protection that are offered. This article aims to unravel the mysteries of the different types of LED power supplies and how they operate in order to ease the selection process.
How to Choose the Right Power Supply for Your LED Lighting Project - [Link]
The new iW3606 and iW3608 single-stage, solid state lighting (SSL) LED drivers from iWatt feature a wide, flicker-free dimming range from 100% all the way down to 1% of measured light, to closely match the dimming performance of incandescent bulbs. This enables the smooth, “natural” dimming, with no light drop-out at the low end of the dimming range and virtually no dead travel where the light turns off before the dimmer control reaches the bottom of its travel. The very low internal power consumption of the iW3606 and iW3608 allows them to start at a very low dimming level of <5% of light output. This virtually eliminates pop-on, a phenomenon where the light does not turn on at low dimmer levels and as the dimmer level is raised, the light suddenly turns on. This also helps eliminate popcorning effects, in which various bulbs in multiple-light installations on the same dimmer circuit can turn on at different dimmer setting thresholds. [via]
New LED Drivers Deliver Exceptional Bulb Dimming Performance - [Link]