This kit builds on a famous LM3916 VU bargraph driver chip from TI/National semiconductor. The chip is essentially a constant current 10 segment driver fed by an array of comparators. It also provides internal reference voltage to set the rail of the precision resistor network feeding the comparator reference inputs. A signal coming in then determines how many signals are lit. Depending on the mode selected, either bargraph or a single dot is displayed. This particular kit is using LM3916, optimized for audio meter applications but could also be used with LM3914 and LM3915 parts to get linear and log response respectively (mainly set by the individual resistance values of internal divider networks).
LM3916 LED bargraph/ VU meter – [Link]
By Steven Keeping:
An entire product and manufacturing infrastructure was built at the start of this decade in anticipation of demand from TV manufacturers for LED backlighting. TV makers were under extreme price pressure from consumers and demanded the LED makers came up with inexpensive backlighting solutions. (See TechZone article “LED Backlighting Enhances LCD TV Picture Quality.”) To support the nascent LED TV sector, the LED makers more than doubled manufacturing capacity and added a similar level of support for the plastic packaging used to mount the backlighting LEDs.
This article provides an overview of the mid-power LED sector with examples of plastic- and ceramic-packaged devices from leading LED vendors.
Mid-Power LEDs Offer Less Expensive Alternative for Lighting Applications – [Link]
I stumbled on these lights at the local Home Depot store this weekend, and was intrigues by the price ($9.95 despite being listed at $20 online) and also the versatility. You can simply screw one into an exposed lamp holder and end up with a fixture instead of a bare bulb, while also using a lot less energy.Or you can use a supplied socket with a pigtail and wire it to a ceiling box. In my case, I was looking to improve garage lighting. A single 60W bulb was just not cutting it and I am not a big user of fluorescents.
Quick teardown- what’s inside a Home Depot 7in LED Easy light – [Link]
By Steven Keeping:
Until recently, a lighting designer looking to take advantage of the efficacy, longevity, and robustness of LEDs for his/her next luminaire was faced with some key challenges.
Among the toughest of these was the need to work out how many discrete LEDs were required to achieve the required “lumen density” (light output per unit area) for the product, and then design a circuit board that took into account the power- and thermal-requirements of this array without consuming too much space inside the lamp. Then the engineer needed to make sure that all of the LEDs in the group produced an identical color to meet the consumers’ expectations.
Today, a simpler solution is at hand. LED makers have introduced a new form of packaging for their high-power devices: the chip-on-board (COB) LED array. In supplying these units, the LED maker has done the work of matching the individual LEDs and designing a suitable substrate to carry the “light engine.” Better yet, COB LED arrays allow LED makers to take advantage of efficiency-enhancing techniques such as “remote phosphor”.
This article reviews the latest commercially available examples of COB LED arrays and considers how the sector will develop in the near future.
The Rise of Chip-on-Board LED Modules – [Link]
Syst3mX @ instructables writes:
One day I was sitting behind my desk at work and I got that weird need to build something, after looking around for a bit I got my eye on an LED matrix and that sparked an idea in my head : “I WANNA MAKE A TAMAGOTCHI”.
So for those of you that don’t know what the heck is a Tamagotchi here is a little snip-it from wikipedia :
“The Tamagotchi (たまごっち Tamagocchi?) is a handheld digital pet, created in Japan by Akihiro Yokoi of WiZ and Aki Maita of Bandai. It was first sold by Bandai in 1996 in Japan.”
So my take on this classic toy is to make it in to a desktop gadget with an LED matrix for a display, and an Arduino for brains to make it more accessible to people. With that said join me as we design,build and program the World’s first (As far as I know) desktop Tamagotchi.
Make a Desktop Tamagotchi – [Link]
hardwarehank @ instructables.com writes:
The Atmel ATTiny85 chip is an 8-pin MCU that is totally awesome. If you’ve been programming with the bigger boys (the ATMega series), these are a nice adventure – you’re rather limited in the number of output pins, but a creative design gives us a lot of flexibility in a very small package.
You’ve seen them – those “Apple computers.” Probably in the hands of some Hipster in Portland, while riding his fixie and wearing those thick framed glasses. That pulsating light when Apple laptops are asleep is so … sooooothing. You just want to go to sleep watching it. You know you do.
Today, we’re going to replicate that using our ATTiny85. It’s really easy, and most of it can be implemented in hardware instead of code (!!!).
Apple-style LED pulsing using a $1.30 MCU – [Link]
xlisus @ instructables.com writes:
Choose the hue of light that makes you feel more comfortable.
Simple bluetooth remote control from which you can modify lighting from your mobile device or tablet.
– You have two separate RGB channels where you can get different colors per channel.
– Control adjustable intensity.
– Do it yourself .
– Thanks to the arduino platform in minutes you ‘ll Omniblug armed and ready for use.
Discover all the features provided. Is very easy install this small device.
Android Bluetooth Control Led RGB – [Link]
To satisfy electronic DIY hobbyists, ICStation has developed MAX7219 Dot Matrix Module. It uses the Max7219 chip which do a great job on saving of MCU I/O. It can not only control each point individually, but also can be extended without limitation to meet your requirements on LED Sign, Team Logo and so on.
What’s more, it’s controlled by the STM8S003F3 MCU with 1K data storge space which is low cost, low power consumption, very powerful.
DIY LED Sign with MAX7219 Dot Matrix Module – [Link]
This GU10 LED spot light is cheap (£3 including postage) and bright. But it’s also lethal! There’s a 50% chance of putting live mains within a few microns of the metal casing (which is what you’ll be holding when you insert it) and there’s no earth to protect you. It’s like playing Russian Roulette with 240v AC mains. This sort of thing gives new technology a bad name. Avoid it if you want to stay alive.
Dangerous GU10 LED Spot Light is Cheap and Bright but could Kill You – Seriously – [Link]
Julian Ilett writes:
I discovered that due to a lucky co-incidence of voltage and internal resistance, a 100W LED can be connected directly across the terminals of two 18V Nickel Cadmium power tool batteries. And that means you can build a 100 Watt (7,500 Lumens) flashlight for less than $10 (not including batteries).
Monster 7,500 Lumens 100W LED Flashlight for under $10 – [Link]