Being a big fan of Fresnel lenses I was eager to relamp with this old stage lamp with an LED source. While the CXA2011 isn’t the newest package it was handy. A future upgrade to the 25XX might be in order in the near future. Pushing it to 700mA required active heat sinking on account of the enclosed space so I utilized a Synjet. The output is a very pleasant 3000K semi spot through the lens. The last picture is of the phosphor on the chip being excited by a royal blue light source outside of the lamp, the result is a faint orange glow.
This was a custom build for a customer looking for a variable output flood lamp to be used with a small solar panel and battery system. The Cree CXA1507 (3000K) package is driven by a boost puck with a max output of 350mA but tuned down to 200mA for reduced power consumption and better thermal performance (case temp of about 30c) . While this was just a prototype the final version was to be water resistant using some type of gasket around the lens. Future builds of this lamp will most likely not be machined from a single block of aluminum. The anodizing is HA type 3 and mostly likely overkill for this application but it adds a nice touch. A standard bolt hole (1/4-20) was added for versatility in mounting.
I have been working more with copper recently because it is so easy to drill and bend as well as conducts heat so nicely. The point of this build was to make an almost miniature model of a reading lamp that provided a usable amount of light. The emitters used in this build are Cree ML-Es in the 3000K color temperature run at about 170mA. The output at the emitters is maybe 150 lumens but is very pleasant to read by. Because these LEDs have an operating current of 150-175mA I had to make a driver for the application and because the driver was so simple I decided to make the components exposed. Because of the low drive current the entire setup stays warm to the touch and does not require finned heat sinking. The base is made out of black Delrin, it is very easy to machine and durable. The larger transistor is screwed down with a #4 screw, tapping the Delrin was like going through butter. I look forward to making more projects out of Delrin.
This is one of the biggest accent lighting installs I have done entirely with RGB tape/strip lighting. The bar is located in Collegetown in Ithaca, NY where a friend of mine asked if I could do some lighting at his new bar. 200 linear feet of RGB LEDs went into the production of this bar along with 3 controllers, 10 signal amplifiers and lots of soldering. The bar is divided into 3 separate lighting zones: the bottle racks are on one zone, the face of the bar is on a second and the wall opposite the bar the 3rd. They can be set to illuminate red, green, blue or any color in between, and the zones can be all on the same input signal or on separate signals.
All of the walls are painted with a final coat that is glossy and the ceiling is a gold color that reflects light very well, especially from the bottle racks. The face of the bar was done in aluminum flashing for a semi reflective finish. The rest of the lighting in the bar is incandescent lighting for a warm environment.
Many of the pictures were taken in sequence to show how different the bar looks under different lighting conditions.
Below are a few pictures of the bar in the making showing some of the lights out of phase.
I’ve been playing with XP-G triples as a general light engine now for some time and have finally come around to using some warmer tint emitters (4K color temperature) producing 354 emitter lumens at 350mA per LED. This puts us over the 100 lumen per watt in a nice neutral light. The build below is a rough prototype of a light fixture that would support this light engine and not need visible heat sinks. At 350mA the light fixture stays cool to the touch ensuring lamp life >50,000 hours until 70% light output occurs. The material is aluminum stock about 4″ x 10″ sandwiched in between 2 quarter inch pieces of plexi glass. The power to the lights is supplied by an Xitanium 350mA driver via the black wires that also support the light fixture.
Recently I have been doing more work with RGB (red, green, blue) flexible strip lighting. While it is a very simple product it can can make for great lighting effects.
Below is a simple setup photographed in blue, green and red.
Below is a close up of a emitter on the strip. Each emitter has a red, green and blue die in each “LED”.
I have been playing with 20mm triple XP-E and XP-G series boards to see how small of a foot print they can make while pushing 600+ lumens.
This latest build was on the Surefire e-series platform that was originally incandescent and retro fitted it to an LED based light source. I am using XP-E R3 emitters because of their narrower light emission than the XP-G die. While they have some reduced output when compared to the XP-G R5 which I used in my last build, I was able to order 5000k color over the 6500k flavor most of the XP-G R5s come in giving them a “cleaner” looking white output. The beam becomes floody very fast because the optic that is designed to go with this board is only about 20mm in diameter and about 7mm tall. With the narrowest 16.4 degree Carclo optic the light is very usable for distances under 50 feet. Given that the foot print of the entire light is about 1″ at its thickest and about 3 1/2″ it is a potent little light.
The base head/bezel is from an E2e Surefire, the body is from a Surefire E1b and the tail cap is from TnC Products.
While copper is far more expensive than aluminum it does transfer/dissipate far better than aluminum. The idea was to create a sandwich with open space in the middle to allow for passive cooling and to have the spacers in between the two copper places to transfer heat to the front plate. The unit is in testing to ensure that temperatures stay low at a 700mA drive current.
I believe I’ve found the new building block for general lot-o-light needed applications. At 417 emitter lumens from the triple star at 350mA. The module has a variety of optics that it accepts from narrow clear lenses to wide angle frosted lenses. I have it currently mounted to a piece of copper from heat transfer reasons. Several of these modules could easily provide over 600 lumens after optics will consuming only 7 watts after driver! While the R5s are a cooler tint, they do provide about 130 lumens of light per watt which is light years a head of most consumer products. I will post more on this as I install this module into some fixtures.
These were some custom made warm tint light strips for art work at a local studio in Ithaca. Cree XR-E emitters were used in this install. The power for these lights is delivered by the wires that suspend the lights for a subtle install.
For reference the lights are mounted to an aluminum strip 2″ wide by 18″ by 1/8″ thick. 3 LEds per strip putting out about 25 watts worth of light per strip.