turning the P1-CE into a fixed spotlight

[Illum]

the P1-CE's been with me for awhile now, but because of newer bin CREEs its been sitting un-EDC'd on the shelf. I used it to illuminate a picture frame once and its a pretty good spotlight.

I'm thinking of drilling a hole on the body tube from the rear. loc-tite [blue kind] the bezel in place and fill the hole with epoxy after running wire through it and soldering the tips to the light engine.

boring out a square heatsink relatively close to the size of the P1's diameter, install the bezel in the heatsink, epoxy the area. the heatsink can be easily modified for mounting applications.

I have one of these unused: http://tinyurl.com/3x4d9u
Would the P1 run on a wall adapter? [if necessary can caps be used to control ripple?]

Theoretically can the P1-CE's light engine take 24 hour operation provided sufficient heat sinking is available?

the original idea was to build it into a stationary goose neck originally made for microphones and use that as a movable workbench light...but now that I look at the size closely I basically have to bore out the ENTIRE bottom for it to remotely fit:shakehead

 

[PhotonBoy]

These LEDs are spec'd for 50,000 - 100,000 hours, so they should run at least 5 - 10 years non-stop to 50% brightness.

 

[Stromberg]

Nice idea Illum_the_nation. More than a "torchaholic" I'm "fixaholic" -> interested of using leds as a fixed lighting. If constructed properly, P1-CE should become very nice looking fixed light.

 

[worldedit]

The power source seems to have enough mA. What do you mean with caps to controll ripple?

 

[Illum]

PhotonBoy, I'm not concerned about the LED's life, I'm concerned about the ability of the driver board to take the load and heat continuously. I mean gee, does fenix know to design a flashlight with 24+ hour runtimes on high?

The power source seems to have enough mA. What do you mean with caps to controll ripple?

well, I was told that the DC output from typical AC adapters is pretty "noisy"
from what I know, capacitors are used to "filter" out these noises. I guess ripple isn't the word for it

as of currently I'm still werking on a previous 12V fixed lighting project, so I'm just gathering some info on this new project and or give ideas to those who have the time. :thumbsup:

 

[Stromberg]

well, I was told that the DC output from typical AC adapters is pretty "noisy"
from what I know, capacitors are used to "filter" out these noises. I guess ripple isn't the word for it

It depends of the adapter. Some, especially cheap ones, are usually unregulated and output may be very "dirty" and well above nominal voltage when under small load. For example over 16 volts in 12VDC adapter when used with 5mm led + resistor.

 

[Handlobraesing]

The Iomega zip drive adapter provides a clean, 5.0v 1A. You'll probably have to use a few diodes in series to bring the voltage below 4.0v and by that time, you have a horribly inefficient light fixture (input power from the plug to lumens output at the front)

 

[SafetyBob]

I have been considering something very similar to your activities too.

I think the answer may be a very small, quality fan. Think about the 20mm or less fan that came on may a early video card. Yes it was run at 12 volts, but if it can run at 3 volts, you may have your cooling issue resolved. If not there are small 5 volt fans running at 3 that certainly should be ok.

As pointed out above, if you could somehow create a large enough heatsink, you should be OK. Perhaps some sort of fins, added on to the outside of the housing could do the trick.

Let us know how this comes out. I would be interested on how this all comes out.

Bob E.

 

[Illum]

I decided not to destroy my P1-CE as of yet....I got back to using it here and there and it made me change my mind:candle:
Besides, I have a shortage on heatsinks anyway.

most of my "home made" projects are proposed on a weekend/$50 budget but by the time I actually get something to work the way I wanted it usually take from a week to a month and collectively about $200 and by that time I would've lost the excitement I had when I proposed the project:shakehead

 

[jrminky]

The Iomega zip drive adapter provides a clean, 5.0v 1A. You'll probably have to use a few diodes in series to bring the voltage below 4.0v and by that time, you have a horribly inefficient light fixture (input power from the plug to lumens output at the front)

This leads to a question that I've had for a while: when making an LED fixture powered by mains, we have to take into account the efficiency of all the components. A spotlight or lamp with, say, 9W worth of 120 lm/W LEDs looks good on paper but if the power supply and LED driver are each only 80% efficient and if the heatsink needs a 3W fan, you're going to be drawing almost 18W from the wall and so the fixture's overall lm/W drops to around 60. Still a lot better than halogen but it's merely comparable to CFL.

Now, to the question: I know efficient drivers can be had for relatively cheaply (IIRC, KD and DX have some). What about small, efficient power supplies? Can a small SMPS be had for cheap? What kind of efficiencies can one expect from a small SMPS? 80%? 90%?

 

[Illum]

sure drivers are cheap, but if want the light independent from a "battery" based system you'll have to tap AC. A rectifier-bridge is a good option...but often exclusive of LED drivers [with the exception of Xitanium et al.]

when your thinking about making something using what you have/discarded from consumer electronics one of the last things I would worry over is efficiency.

sure you could get a new driver and run an LED on a dedicated piece of circuitry but that costs money...more than I could earn selling unused wall worts.

I figured hey.
AC power + DC power supply + Resistor + LED

would have a better efficiency than

AC power + DC power supply + LED driver + LED

since the two circuits won't conflict each other, say if the wall wort is only willing to yield 350ma but the LED driver wants to pull 500ma from the supply, both will be straining really hard and the race in endurance will finish with either or both going

 

[jrminky]

I wasn't trying to criticize your design and I hope I didn't come across sounding as if I was. In fact, I've often thought of doing the same thing with my single-mode C3 that's been gathering dust. My efficiency comments were directed toward the general task of mains-powered LED lighting.

Anyway, there were a few reasons why it might make sense to use a driver in a DIY mains-powered fixture refit. First, it lets you more easily use off-the-shelf power supplies. A constant-current power supply capable of driving 9 LEDs at 700ma might be expensive while a 12V@3A power supply can be had for less than $10 (and since a driver generally works over a range of input voltages, you don't have to worry so much about the power supply's voltage regulation). Second, a lot of fixtures that seem ideal for LED refit already have low-voltage transformers (landscape lights and MR16 track lights come to mind) and it might make sense to reuse them. [1]

Consider the MR16 track lights typically found at Home Depot. Here, the track sits at 120V and each light module has its own 12V transformer. It should be a lot cheaper to reuse those 12V modules and simply add a bridge rectifier and a driver to each light module rather than start from scratch.

[1] Note that I'm ignoring the efficiency of the transformer that comes with these kits. They might be lousy.

 

[Illum]

no offense taken at all, I was simply explaining my share of reasoning
all ideas are appreciated, even better if my thread provokes your thought and design for your own spotlight of the the same category:wave:

 

[IMSabbel]

This thread got me thinking:
"real", not shitty fixed led lights are quite rare yet.

How about the following idea:
Use a common low voltage 12V halogen setup (with lights that get snapped on rails), and just instead of halogen bulbs put in some cheap flashlight heads of 2CR123 lights with buck converters in.
(of course only if the buck converter isnt just using linear voltage drop).