Building flashlights seems to be a fixation of mine. I built my first one at age 5 or so, and now that I’m nearing ten times that age, I’m still building flashlights. This time the project of choice was a high power LED flashlight with several interesting features:
A high power LED flashlight - [Link]
Luca Dentella has published his latest project: BlueMatrix. [via]
It’s a portable LED matrix display based on Arduino Uno, powered by a Lipo battery and connected via Bluetooth to a personal computer or an Android smartphone. I’ve also developed the controlling app for Android, available on Google’s PlayStore.
All the schematics, source files, inkscape files for the enclosure etc., are available on my blog and in my GitHub repository.
BlueMatrix – Bluetooth controlled LED matrix - [Link]
Get fit for summer with your own activity monitor from this Adafruit Tutorial!
Keep that New Years resolution of getting fit by staying safe with a neopixel motion activated running band powered by Flora, Adafruit’s wearables electronics platform.
This is the activity monitor you’ll want to wear outside and at the dance club!
Get Fit For Summer With A DIY Neopixel Motion Activated Running Band - [Link]
One example for all – we compared super bright red LED Kingbright SR-J4 with a standard type of the same producer.
Comparison of features is usually the most exact method how to compare two similar components. But what´s the result in praxis? At such a parameter like luminous intensity, we´re probably the most interested in a subjective perception – how it shines in a real design. That´s why we decided to bring you a direct comparison. On the left side, there´s always a high efficient LED from the SR-J4 series, namely L7104SRC-J4 and a standard quality LED from the L-934SRC-C series is on the right side (it´s worth to mention that even this type has a higher than standard luminous flux). LEDs were connected in series, so they were driven by the same current. We used two common values – 1 mA and 10 mA.
And a conclusion? Both types have their advantages – the standard type mainly in the price. In respect to a very affordable price of a more efficient type, it´s more advisable to use this new type SR-J4 as well as other similar, for example series ZGK, SRY and other. In result, an efficient type will always bring a lower power consumption, longer battery life, trouble-free connection to logic circuits etc.
We got light on luminance of universal LEDs - [Link]
anool @ wyolum.com builds a pulse lamp controller for the parking light of his KTM bike. He writes:
My brother is a Mechanical Engineer who loves his KTM Duke 200 bike. He asked me to build this circuit : http://sunbizhosting.co.uk/~spiral/blog/?p=227 for a ‘heartbeat’ lamp controller for the parking light. A Neutral Detect (ND) signal controls the lamp pulsing. When ND is HIGH, the Lamp is fully lit. When ND goes LOW, the lamp starts pulsing.
I’m not familiar with PIC microcontrollers, and didn’t want to dabble in “C” code. I’d be comfortable with an Arduino, but even the smallest ATMega seemed too big (and overkill) for this simple requirement. How about an ATTiny ? A bit of Googling, and I found this excellent resource for running the Arduino environment on the ATTiny : http://hlt.media.mit.edu/?p=1695
p.u.l.s.e. – fader control for Motorcycle parking Lamp - [Link]
by Dave Young:
A month ago Newegg sold the 40W-equivilant Collection LED for $5 each. This was the first time I saw LED bulbs going for almost as little as CFLs, so I picked up a few. Not having bought LED bulbs before I did what any normal person would: I tore it apart!
40W ‘Collection LED’ Bulb Teardown - [Link]
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]