Author Topic: Harbor Freight 12volt CFL to LED bulb modification (Read 12911 times)

yuandrew · « **on:** December 11, 2010, 03:48:57 AM »

I've been working with the guys who operate the SoCal solar store in Montclair/Upland for the last couple weeks. One of the products they build and sell were "Emergency Mobile power/lighting kits" based on components from the Harbor Freight 45 watt solar kit only they replaced the three 15 watt panels with a single 30 watt polycrystalline panel and uses the TW-910 charge controller. All the components are housed in a Stanley 2 in one 2-in-1 Mobile Work Center/Tote with the battery in the bottom compartment.

At first, they included the 12 volt/5 watt CFLs that come with the Harbor Freight kit but they were dim and blue. The guy who constructed the kits, Richard Ponce, wanted some brighter and better quality light and tried some other 12 volt CFLs they had in the store but then decided he wanted an LED based source. At the moment, no one made a 12 volt LED bulb with a medium base so I was given the task of making one and was provided with a HF 12 volt/5 watt CFL to use. I didn't take any pictures during the build but I'll draw as I explain.

Unscrewed the diffuser from over the tubes then if one holds the base and gives the tubes a quarter-turn, the insert with the tubes on top and the circuit board on the bottom will come out.

Cut the wires going to the circuit board and toss that upper section with the fluorescent tubes/driver aside. You'll now have an empty base with wires sticking out.

I purchased one of these LED-MR16 bulbs from Home Depot . They are made by Lighting Science Group and called the "Definity" MR-16 lamp but Home Depot sells them under their "EcoSmart" house brand

Soldered the lamp's pins to the wires in the Harbor Freight bulb's base. Since MR-16 Halogens are powered from 12 volts AC, the LED MR-16 had a bridge-rectifier built in so it didn't matter which pin you connected the + and - to.

After taping the MR-16 up inside the CFL base and screwing the top back on, I fired it up and noticed how it directed all the light forward. It would be nicer if it spread the light around instead so I looked for something to use as a diffuser. Found a translucent 35mm film canister.

Taped that to the top of the MR-16 LED bulb so the light shined into the canister which disperses it. I also used the lid from the film canister to make a platform for the MR-16 to sit on inside the CFL base. Made two holes for the pins to stick through, wires hooked up on the other side, taped that into the CFL base and put it back together.

The film canister made all the difference in spreading the light around the room while also providing a diffused "spot" out the end of the bulb. The light appears much brighter and warmer when compared to the original fluorescent.

Simen · « **Reply #1 on:** December 11, 2010, 05:22:15 AM »

You might want to try to get the 'lens' off that mr16 bulb; it concentrates the light, and without it you'll probably won't need that extra film-canister diffusor.

Also, those mr16 bulbs have power-leds, and those cooling fins are not for show, so you should probably drill some holes in the cfl-base for cooling, if not already present.

Rover · « **Reply #2 on:** December 11, 2010, 07:56:32 AM »

I congratulate you on the effort.

They sell e27 (medium base) to bi-pin converters though. They also sell 12V e27 base led lights. (all ebay) . I recently purchased a 36 led (SMD) light off of ebay (shipped from HK) , unlike most this one is built like a little cylinder with vertical rows of 6 leds around the cylinder. It has a an e27 base , and rated at 5W. It's currently installed in a pole lamp in front of my house and puts out a considerable amount of light for the wattage, as a subjective estimate, I'd say between a 40-50W incandescent.

Much brighter than the 5W HF, and with a somewhat omni directional light as opposed to the normal flood/spot led configurations.

I have this running from a 12v power suppy in the garage through a Watts Up meter until I can get enough wire to run it from my bank in the back yard. Based on the meter the 5W consumption is accurate.

Boss · « **Reply #3 on:** December 11, 2010, 01:59:34 PM »

Quote

Found a translucent 35mm film canister.

I never heard of a translucent 35mm film canister, wouldn't transmission of light defeat the purpose of a film canister?
I see the need to disperse the light but ...

yuandrew · « **Reply #4 on:** December 15, 2010, 11:38:54 PM »

FujiFilm canisters have been translucent white for a long time. Kodak ones were traditionally black with a gray cap but they had some films (Royal Gold was one of them) which came in a translucent white canister with a black cap that said Kodak Select.