Miscellaneous LEDs and LED-related "stuff"


Sharp 50-LED Red/Green/Yellow Module
(Purchased 03-29-05, received 04-02-05)

This is an item I saw on Ebay a few days ago, and purchased because it has LEDs in it. :-)
It is a circular module containing 50 5mm (T1 3/4) LEDs (14 red and 36 green), with "cat eye" or "super oval" water-clear epoxy bodies, so they project an oval beam of approximately 45 (horizontal) by 10 (vertical).

Here is a photograph of the front of the module.

This module requires two different voltages: -13.2 volts for the red LEDs and -19.0 volts for the green LEDs.
The red circuit draws 40mA, and the green circuit draws 80mA.
At 42mA, the forward voltage on the red LEDs is 12.72 volts.
I have not yet found/connected a PSU with a high enough voltage to run the green LEDs.

It also has an unusual wiring configuration, having a common anode (+) connection; the red and green LED connections are (-) cathode connections. The voltage ratings shown here are near maximum ratings; it's OK to operate these with slightly lower voltages.

This module was prepped with a small connector on the end of its wires; I had to cut this connector off in order to apply power to it. The photograph directly below was taken with the module in its feral state; with the connector as of yet uncut.

Here is a photograph of the side of the module.

Here is a photograph of the connector, compared in size with an ordinary 5mm LED.

And here is a photograph showing the red LEDs illuminated at a percent or two of maximum intensity, so the image did not bloom on the camera.

The power supply I'm using right now does not generate a high enough voltage to energise the green LEDs; that's why you don't see them on this web page.

In early 2003 I received this little guy from a Candlepower Forums member.
It's an LED pedestrian signal, consisting of a whole bunch of red LEDs on a board, plus a circuit that enables them to run directly from 120 volts AC. Here's the link to the CPF pages they appear on.

This particular model has a short AC cord with a regular two prong plug on it. There is also a plastic "pipe" affixed to the bottom of the circuit board with silicone RTV, and two plastic stand-offs screwed to the board - these can be removed if you wish to enclose the LED hand in a shadow box or picture frame. Remember though, the PCB is "live" at 120 volts AC, so you don't want to have any metal or other conductive compound in your frame where it could touch the bottom (underside) of the board.

The LED "don't walk" hand shown in front of my computer monitor - with forced-on fill flash! It is very bright - not something you'd want to stare into close-up for too long. :-O
(Note: This LED hand is different from the one shown below, so you'll want to keep reading. :-)

LEDs. You'll see them everywhere if you look for them.

This pair of pedestrian signals were found at the intersection of 7th and Olive Way in downtown Seattle. They are the only LED pedestrian signals I've found in this city.

This model displays a red hand for the "don't walk" signal, and a white 'man walking' plus a countdown timer for the "walk" signal. Once the timer reaches "0", the red hand is displayed with no additional fanfare.
The LEDs are behind a baffle, and I could not reach high enough to place the camera in front of these signals, so the baffle distorts & blocks some of the LEDs out in these photos. When viewed from across the street (as intended), all of the symbols appear bright and very much whole.

The red bulbs in some of Seattle's three-way traffic signals have been converted to LED modules in many of the units, but I have not yet found any with LEDs used in the yellow or green portion.

Enviro-Lite LED Universal "T" Lamp Exit Sign Retrofit
Here is an odd LED fixture that showed up in the mail a day or so ago.
Housed in a "T"-shaped white plastic case, this unit features 20 slightly diffused, bright red LEDs and a candelabra bulb base.
Originally meant to replace the incandescent lamp in 120VAC "EXIT" signs, this fixture seems to hold up to that promise, all while using only about 0.9 watt of electricity.
(In comparison, a typical bathroom nightlight uses 4.5 to 7 watts!)

Exit sign retrofit 'bulb'
Replacement 'bulb' for those "EXIT" signs.

Part of the box that came with it shows this to be manufactured by Area Lighting Research, Inc. and is their Model T-120. An instructional sheet that comes with it also explains how they are installed, and how to modify the sign's diffuser if necessary.

Since I don't have an EXIT sign handy to try it in, I ended up simply screwing it into my chandelier, which uses candelabra-base light bulbs.
Some signs may require you to install a standard base to candelabra base adapter, however this is all outlined in the instructions, and the LED fixture is made to accomodate this potential need.

I found the fixture to maintain high lighting levels even when installed on a dimmer circuit, and continues to perform well even when the incandescent lamps on the same circuit have been dimmed to 10%.
The product is UL listed and runs quite cool even over an extended time.

LED Retro, Inc. Tubular LED "Light Bulb"
Here is a different kind of exit sign retrofit bulb; meant for the older style of signs which use a single tubular light bulb to illuminate a single-sided signface.
Made by LED Retro out of Ontario Canada, the packing shows this to be a model XL-100, 120 volts, 1 watt. (The bulb itself has this pinned down to 1.3 watts).

Featuring a straight line of bright red, clear-case LEDs, not only would this fit your older style EXIT sign using a standard candelabra base bulb, but might make a very unusual and attention-getting Christmas tree topper as well.
tubular 'bulb' LED
LED 'bulb' and its packaging.

The manufacturer supposedly guarantees this for ten full years; however, when I screwed it into my chandelier (base-down orientation), the top of the 'bulb' got quite warm, and the inside of the glass is showing signs of clouding up from some component inside that's running too hot. The bulb is also stinky and smells of overheated circuitry. It has a CSA rating (the Canadian version of UL) but no UL listing.
The date of manufacture is April 1996; it is very likely that newer products are indeed UL listed and they have probably licked the overheating problem.

The insides of this lamp appear relatively simple, consisting of the LEDs on a board, three capacitors and two small (1/2 watt) resistors. The uppermost capacitor (appears to be a high voltage ceramic) seems to be what's getting hot. The other two (high voltage mylars) run cool. I'm not sure how the LEDs are protected against excessive reverse bias voltage since I don't see any diodes of any kind inside.
But the silly thing works, and I guess that's what matters most. :)

Like the "T" fixture directly above, this one also operates at near full intensity on a dimmer circuit even when ordinary bulbs are dimmed to 10 or 15% of full.

tubular 'bulb' LED
Shown being tested in a jimmy-rigged chandelier. They won't let me drill a hole in my ceiling to hang it.

Infrared LED "strip" found in a copier.
A fan of the website sent me a couple of interesting pulls from a copier. One was a long, skinny board crammed full of tiny, tiny infrared LED emitters and some kind of onboard controller. When lit, the LEDs are *barely* visible to the eye, but appear on a digital camera as a yellow-orange stripe running the length of the board as you see in the large picture below. Judging by how this particular camera "sees" infrared radiation, the LEDs on this board are probably around 780 to 810nm.

When greatly magnified, you see tiny "lenses" all along the strip, which the LED chips shine through.

It is not clear what this was for, but it appears that it *might* be enough to activate some photosensitive chemical, and create an image on that material (a drum rotated by a stepper motor, perhaps) by modulating the many hundreds of little LEDs in the strip like the electron beam does in the picture tube of a TV set. Only in this case, the drum moves instead of the energy source.

Also included was a second board labelled "eraser board" which contains seven rather ordinary looking rectangular red LEDs spaced about an inch apart from one another.

(Update 12-16-08): I received an email, describing the exact purpose of this LED strip.
The contents of this email are as follows; his name & email address have been omitted to protect his privacy:

What you have is parts of a Contact Image Sensor (CIS) which is used in low-cost fax machines, scanners, and copiers.
Instead of using mirrors and a round glass lens to focus a reduced-scale image of the scanned document onto a linear CCD detector, a CIS has detector array the full width of the scanned document.

The enabling technology is the array of rod lenses (GRIN lenses) which nearly touches the document surface and form a very close, 1:1 scale, non-inverted (!) image on the detector array. www.datvision.com/01_Camera_15/Tichawa/CIS.htm www.photo.epson.co.uk/technology/scanners/ccd.htm

Many CIS units have RGB LED illumination, with three LED die attached directly to PCB, and a clear plastic light pipe to distribute the light into a long narrow strip.

LEDs in different stages of manufacture (Cree-style rod-shaped, and Cree-style rectangular)
Here are two unusual pieces you don't come across every day. LEDs still on their metal dies right from the manufacturer's machinery.
The first picture shows a long, rod-shaped LED casing with two chips in it; these were probably destined to become long, skinny indicator lights in somebody's high-end stereo system or keyboard lights in an expensive cellular telephone. They are still attached to the metal their leadframes are coined from, and as far as I can determine, at least some of them might actually work if I cut them out of the frame. Although the LED bodies are already in place, the window or epoxy fill has not yet been put in, so the LED chips themselves are still exposed to atmosphere.
Birth of an LED
Miniature PC-mount LED dial lights in mid-manufacture.

Update 10-14-00: I finally got curious enough to cut one of these out of the frame, and determined that they are "double green" LEDs!
They use two yellow-green chips in series, and were probably meant to be used as power indicators in some high-tech piece of home electronics.

This next picture shows some transparent rectangular LEDs all ready to come off their framework - in this case, these were at the stage where they cut the anode lead shorter than the cathode, and they do in fact light up if you hook them up. These particular specimens glow a bright red.
They are also a little unusual in that the anode (+ connection) is on the larger side rather than on the small like most other LEDs.

Birth of an LED
Rectangular LEDs, just about ready to go.

LED Cluster Modules for Traffic Signals & Signs (Various manufacturers)

LED Light

These things are modules containing multiple LED arrays, or "cluster modules" as they are sometimes sold as on the surplus market.
Although cluster modules come in a variety of shapes and sizes, these particular modules are all similar in appearance and were probably made by the same manufacturer.

Each module is constructed of a tough black plastic, and has a sun shield or hood overhanging the exposed LEDs on the front. The back side contains a rubber "O" ring and one or more brass threaded inserts; these were probably designed to be used in traffic message boards or similar high-visibility signage. Several different configurations & colors arrived; they will be described seperately.

LED Light These modules were originally intended to be used with a special controller & multiplexer board; however once you know how the modules themselves are wired internally, you can just cut off the special plug and hook them up to your own resistor (if necessary) and power source.

Although I know little about how this controller works, it has two data ports which allow modules (or even seperate halves of larger ones) to be switched on and off at will. For the purposes of this discussion, the clusters are just going to be run off ordinary DC power.

Each cluster comes with three wires: a white one, a red one, and a green one. To make things simple, you connect the white wire to the (-) side, and both the red & green wires to the (+) side, and you've got light. Lots of it. A couple of the modules are blindingly bright, and it is very clear they were/are meant for outdoor use; the others are a little dimmer and would work fine indoors.

The smaller sized modules, each containing either 4, 5, 6 or 12 LEDs, are connected so that all of the LEDs come on at once. The larger 16 and 20 LED clusters are split - hook up the white and red, and half of the LEDs come on - hook up the white and green and the other half comes on. Twist the red & green together, and the entire cluster lights up.

new lights
Red modules used on my new red wheelchair.

These clusters are built incredibly tough, and are designed to withstand all kinds of brutal punishment that would be deadly to ordinary incandescent, neon, or fluorescent signal or sign illuminators. The LEDs are potted in place and cannot be knocked out of alignment; in addition, the clusters are equipped with a very beefy "O" ring on the back, which, when affixed to whatever fixture they were made for, essentially made these modules waterproof and darn near bulletproof as well. A sun hood is built in as an integral part of each cluster; however if you must, it may be carefully removed with a wire-blade saw or hot x-acto knife.

LED Light

By far, the brightest of these clusters are those with RED lamps in it. The LEDs appear similar to Nichia's cat's-eye ("super oval") red LED; however because they are potted deeply inside the fixture, I cannot confirm this. When fed approximately 100 milliamps at 10 to 12 volts, the 20-LED red cluster is quite literally blinding, and will fully illuminate a large room even with some ambient light already available. It is approximately as bright as a standard automotive tail lamp with the brake pedal depressed; but uses only about 5% of the current of an incandescent taillight bulb.

Next up is the ORANGE cluster. It's LEDs are different than anything I've ever seen. The photograph above shows the orange cluster near the center; the LEDs bear some resemblance to wingnuts with a tiny dome in the center. They are viewable from the widest angle possible; almost a full 180 degrees. So they aren't as bright when viewed at a distance.
The 16-lamp orange cluster can also be fed 10-12 volts at 100mA.

LED Light
Two red clusters used in my wheelchair.

Dimmest - but still impressive because of their number, are the yellow clusters. These need roughly half the power of either the red or the orange; feed the smaller clusters around 50 milliamps; 75 should do for the larger.
The LEDs in these particular yellow clusters are arranged a little differently. While they all face forward in the orange and red clusters; the yellows are arranged so that 1/3 of them face forward, 1/3 of them face slightly left, and 1/3 face slightly right. The LEDs don't have as wide a beam as others, so this assures that at least some of the LEDs will be visible even if you view the face of the cluster off to one side or other.

Data lines in the controller were locked to allow continuous burn.

Current was metered & increased until the LEDs no longer increased in intensity; then subtracted from the 55mA idle current used by the controller board. The final number gives the cluster's optimum or rated current usage.

Clusters used outside the controller environment may face increased current; any failures will be documented here should they occur.

Environmental testing is taking place with two red and four yellow modules, by attaching them to the exterior of my wheelchair. They will be operated, rain or shine, anytime the chair itself is used - which is multiple times daily.

WHITE 5500-6500K InGaN+phosphor 
ULTRAVIOLET 370-390nm GaN 
BLUE 430nm GaN+SiC
BLUE 450 and 473nm InGaN
BLUE Silicon Carbide
TURQUOISE 495-505nm InGaN
GREEN 525nm InGaN 
YELLOW-GREEN 555-575mn GaAsP & related
YELLOW 585-595nm
AMBER 595-605nm
ORANGE 605-620nm
ORANGISH-RED 620-635nm
RED 640-700nm
INFRARED 700-1300nm
True RGB Full Color LED
Spider (Pirrahna) LEDs
True violet (400-418nm) LEDs
Agilent Barracuda & Prometheus LEDs
Oddball & Miscellaneous LEDs
Programmable RGB LED modules / fixtures
Where to buy these LEDs 
Links to other LED-related websites
The World's First Virtual LED Museum
The Punishment Zone - Where Flashlights Go to Die
Legal horse puckey, etc.
LEDSaurus (on-site LED Mini Mart)

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