LED Archives - Page 3 of 3 - A Leslie Wong Blog

March 4, 2008July 26, 2021

Cree XLamp XR-E R2 Bin

Now that I’m a flashaholic, I’m always looking for brighter LEDs. A recent eBay search for the latest Cree XR-E 7090 white LED R2 bin, I found this Solarforce Cree R2 (5 mode) drop-in.

It’s called a P60 sized drop-in, because that is a Surefire size designation for a reflector-LED-regulator assembly that also fits many different other manufacturers flashlights. The Solarforce drop-in is advertised as 290 lumens (seems unlikely), maximum. The five modes are: strobe, 3 levels of brightness and S.O.S. It was $27.99 USD plus $3.00 shipping. It showed up today in the mail and I was shocked, because delivery from China, where the vendor is located, took only 10 days.

For a comparison test, I used fully charged Ultrafire RCR123 batteries and Ultrafire 502B flashlights with switches replaced with Judco SPST 519PB-ND I bought from Digi-Key. The other P60 size drop-in was a generic Cree P4 module. In the first beamshot, the difference is brightness is minor. I tried another Cree P4 and it put out much less light compared to the Solarforce R2 drop-in. The third beam shot uses the first two modules, but is underexposed 1.5 stops to maximize the visual difference in the two beams.

So did I find a brighter light? I have the feeling I did. I’ll have to check it with my light meter and compare the EVs.

My beamshots were done with a Nikon D70, Nikon 50mm f1.4 lens. Exposure information: ISO 400, 1/30 sec, f2.0.

January 1, 2008July 25, 2021

LED Festoon Bulb Replacement

I bought some “Chrome” surface mount LED modules from Oznium.com to see how they’d work as replacements for automotive Festoon light bulbs (the ones with the pointy ends). The modules are about 2.3″ (60 mm) long with an adhesive strip on the back. The “chrome” is plastic.

Oznium actually sells some LED Dome Light replacements that are 5×5 LED arrays that include common bases with the LED array.

I thought that these modules would fit inside the BMW Bavaria trunk light housing that uses a 8.5 x 37.4 mm Festoon bulb.

The photograph showing the trunk is a little misleading – it’s actually about 4 times brighter than the bulb with the filament – you’d have to strain to read by the light.

December 5, 2007March 25, 2019

Cree XLamp XR-E LED

I just received a bunch of flashlight parts I ordered from Kaidomain.com. Among them, four Cree XLamp XR-E LEDs, Q2 and Q5 bins. I thought I’d mod my Ultrafire C2 flashlight that has a P4 bin Cree with the Q5. I can’t tell the difference between the Q5 and Q2 by looking at the two. I guess I have to do some kind of measurement of current and light output. The Cree XLamp LED Q5 will put out 107 Flux (lumens) when driven at 4 amps – that’s very bright.

One of the four LED’s seems to have a manufacturing defect – see the material in the upper left corner of the chip in the photo?

Two people who offered me help on the Candlepowerforums.com came up with different answers. jtr1962 says it’s the result the dome is starting to detach – he called it internal separation of the silicon filler. WeLight theorized that it was a manufacturing defect and I should return it. I don’t know much about these high power LED’s but I’m learning.

November 9, 2007March 31, 2020

Ultrafire C2 Flashlight

I ordered an Ultrafire C2 flashlight after reading Ernest Sanada’s great review on CandlePower Forums, but delivery from DealExtreme.com in Hong Kong took 5 weeks. They have good prices, but you can’t expect your stuff right away.

I got impatient and ordered another C2 from BatteryJunction.com (highly recommended) – they only took 4 days for delivery.

The Ultrafire C2 uses a Cree XR-E-7090 P4 LED (PDF) which puts out up to 87.4 lumens @ 350 mA, according to Cree. What this actually means is this flashlight is really bright. The manufacturer also says, “White XLamp LEDs are tested for luminous flux and placed into luminous-flux groups.” Your flashaholic calls it binning -they test the LEDs, then throw them into “bins” depending on their output. These Ultrafire C2s use a P4 bin LED.

The Ultrafire’s exterior aluminum is available in two anodized finishes. One C2 I bought is hard anodized to type III specification – it’s gray. The Battery Junction Ultrafire uses the type II specification anodizing – it’s black.

A couple of days ago, DealExtreme came out with an Ultrafire C2 that uses the Cree XRE-7090 Q5 LED, which has a maximum luminous flux of 114 lumens @ 350 mA. What this actually means is this is really, really bright. I ordered two Cree XR-E Q5‘s on star boards from Kaidomain.com, maybe I can stick one in one of my C2s.

I’m becoming a (noob) flashaholic. The last photograph in this group proves it. It’s a beamshot comparing the AA Maglite (using fresh AA alkaline batteries) and the Ultrafire C2 (using RCR123A 3.7v Li-Ion batteries), taken with a Nikon D70, 18-70mm lens at 55mm, color temperature – 5700K, ISO 400, .7 sec., f8. I’m not sure how meaningful this beamshot is, because it was taken from about 15 feet, but it shows the relative brightness for comparison.

AA Maglite and Ultrafire C2 Flashlight beamshot — AA Maglite (left) – Ultrafire C2 (right) Camera: Nikon D70, 18-70mm lens at 55mm, ISO 400, .7 sec., f8 from about 15 feet

October 29, 2007August 31, 2021

Flashlight Modding

I’ve always liked flashlights – I think every kid did. I didn’t know there were serious “flashaholics” until I came upon candlepowerforums.com. These people are very serious about flashlights. Who knew one could spend upwards of $800 for a flashlight?

Look at this thread on the Ultrafire C2. After I read it, I had to have one. The Ultrafire C2 makes my upgraded (Terralux MiniStar2 Extreme LED) Mini-Mag light look like a candle.

Hong Kong, with their cheap manufacturing, seems to be a source for these inexpensive but powerful flashlights. I ordered some parts from dealextreme.com – a Cree P4 LED Emitter and a 3.6V~9V 800mA Regulated IC Circuit Board.

3.6V~9V 800mA Regulated IC Circuit Board and Cree P4 LED

I thought I would use these new parts instead of the original LED and voltage dropping resistor in modding this $12 “SUPER” 7 watt Luxeon LED flashlight I bought from a Hong Kong vendor on eBay.

My first mod sort of failed in that I didn’t consider the position of the new LED in the reflector for that all important beam. I guess that’s how you learn.