Diamond-flashlight 3W Luxeon PR Bulb ?

Anyone try and know anything about http://www.diamond-flashlight.com and their 3W Luxeon PR bulb?

I'm looking to get one for a 4D cheapie lantern. For 19.99 seems like a good deal for a 3W Luxeon in a PR base.... /ubbthreads/images/graemlins/icon3.gif

It's interesting to me that these guys show it sitting in a plastic ring case the same way that Ever-LED's are shipped. DO we know, or suspect that these are made by the same folks? Otherwise I'd be very suspicious as they are almost too good to be true for the price.

Well, I'll wait a week for others to respond, and maybe I'll buy one and have it shipped to Quickbeam for a review (if he's willing that is)

It doesn't appear to be regulated since it only works with 3 cell lights.

Also, it can't be driven enywhere near spec because it would burn up. Even the EverLED gets too hot to touch and it's only driven at around 330mA, and has thermal regulation.

"Otherwise I'd be very suspicious as they are almost too good to be true for the price."

It is too good to be true. You can't run a 3W with only a PR base as the heat sink. I've got a home made 1W resistored PR lamp and it gets way-hot and noticeably dims after a few minutes of run time due to the heat.

Holy mackeral - I think this is the same guy that we were talking about a few months ago in another thread - he bought a HUGE number of led/flashlight related domain names and they all interlink. No one seems to be sure just how legitimate they are. Caveat Emptor (let the buyer beware).

i doubt it will work as claimed.
a 1w in a pr base that i sleeved up to fit tight in a mag bulb holder gets good and hot at 350ma even with the mass of the mags holder as a heatsink.
at an amp it night perform as advertsed...for a few minutes!

Crap, I figured as much... I'm looking to make a quick and diry mod with a cheap 4D lantern from walmart. The PR bulb holder is plastic, anyone have one of these? I might end up with a everled PR bulb instead, out of laziness... but the plastic body makes for a lousy heatsink... grrr

Haha, I may have bitten off more than i can chew

utomatoe, I did this in a $5 Walmart lantern (eveready?). I used a duel TO220 heat sink (about 6 sq. inches surface area, IIRC see heat sinks at mpja.com or other electronic supply & pick one) and a 1w luxeon. I also used an LM317 chip set up for current regulation (640ma) mounted to the other side of the heat sink.

Since the LM317 has overheat protection built in, mounting it to the same heat sink means it will limit current to the luxeon before it gets too hot(maybe a little hotter than spec, but hopefully not too much). Anyway, it doesn't noticably dim even after 30 min. or more operation. I am a little surprised that it doesn't get too hot since there is very little heat conduction (except thru air & plastic) with the plastic housing. Maybe the battery soaks up the excess heat. -RussH

Thanks! I'll give that a try, I've been eyeing the LM317 as well. Would you mind telling me how you wired it up? I'm not entirely sure how it works, any schematics you have would be useful.... I'm more of a follow the schematic and build it kinda guy. I haven't built my own circuit in.... well, a really long time *lol* and they weren't that sophisticated either...

Re: Diamond-flashlight 3W Luxeon PR Bulb? *UPDATE*

From customer service:
[ QUOTE ]

Hi Edwin. The 3 watt we have on the site will only work with the 3-C or 3-D battery Maglite. We could put in a different resister if you wanted a LED for the 4 or 6 battery Maglite.
We have left the Flashlights on for 12 Hours with no heat problem.

The LED will keep the same brightness and will dim as the batteries wear out.


[/ QUOTE ]

Summary: Direct drive, not regulated, almost guaranteed to be underdriven given that it's a 3W.

Re: Diamond-flashlight 3W Luxeon PR Bulb? *UPDATE*

Hmm... if you use the LM317 for current regulation, how do you know how much voltage is going into the emitter? 6V from 4D batteries, and I think 1.5V drop through the LM317(?), that leave 4.5V, a little high for the 1W luxeon that you are using?

I must be missing something here....

Re: Diamond-flashlight 3W Luxeon PR Bulb? *UPDATE*

utomatoe, basically all you do is put a resistor between the adjustment pin and the output pin. The 317 then regulates the voltage across that resistor, R, which cause the output current to be R divided by 1.25. So a 1.2 ohm resistor gives you 1 amp, or a 1 ohm gives you about 800ma. I paralleled several resistors to get close to 2 ohms and ended up with 640ma. I was shooting for 600-700ma, but about 500 - 600 won't be noticably dimmer, and is more my standard range for '1w' luxeons.

Note that .8 amp x 1.25 = 1w. I use 1w resistors up to 1 amp without problems. You could always tac it to the heat sink if that bothers you. This same regulator will work with a 1w, 3w, or 5w provided you supply about 2-3v over what the LED requires (Vf at the supplied current, about 3.6v for 1w & 3w, 7.2v for 5w). The above regulator reached 640ma at about 5.5v and I tested it (bench power supply) to 15v. The LM317 has to drop all of the excess voltage so it gets WARM (& loses efficiency) at any voltage higher than the required minimum.

The following url will take you to a bunch of Nat'l Semi's application notes http://www.national.com/apnotes/PositiveVoltage-Adjustable__v2.html . You might start with this one http://cache.national.com/ds/LM/LM117HV.pdf & look at the typical applications in about the middle of the booklet for the current regulator. HTH, -RussH

Re: Diamond-flashlight 3W Luxeon PR Bulb? *UPDATE*

Ok, so a 4D lantern gives me 6V to play with, and the most output voltage I can get out of an LM317 would be 3-4V? (due to a 2-3V drop thru the LM317).

If I have a H binned Luxeon, with Vf of 3-3.2V, what would happens if I supply it with say 4V at 400mA?

Re: Diamond-flashlight 3W Luxeon PR Bulb? *UPDATE*

utomatoe,

I'm driving a Q2H HD Star in a 4AA Rayovac Kid's lantern with a uFlex at 380 ma. The uFlex obviously costs more than the LM317 and resistor, but you can't beat the efficiency and features of the uFlex.

It runs happily for 5hrs & 20 minutes runtime on high with 4AA alkalines, 12 hours on 4AA lithiums according to George's run time graphs. It'll run for much, much longer when using the lower settings. The uFlex is absolutely superb! AND - the thing can really suck all the useful power from your batts to boot. After just starting to fall out of regulation on highest setting, I put two of those batts into my Opalec and they lit up the red low-batt led. Since the uFlex can still say in regulation at the lower level settings, I imagine it could drain the batts virtually completely.

The uFlex driver is user-configurable for 380 ma or 760 ma, so you might even be able to drive a Lux III from 4D alkalines (and a decent heat sink) in your larger lantern.

The LM317 is inexpensive and easy to use, but I agree with RussH - you need a good 3 Volts above the LED Vf to stay in regulation, and it is not nearly as efficient as a down-switching current regulator like the uFlex from georges80, or a DB400 from dat2zip's sandwich shoppe.

[EDIT - there's always the inexpensive option of using a simple current-limiting resistor for your 4D lantern. You could even use a separate switch to bypass the resistor once you notice the LED starts dimming.]

Have fun!

John

Re: Diamond-flashlight 3W Luxeon PR Bulb? *UPDATE*

I have the same lantern as this one: http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=91058

I'm not sure I have the space for a uFlex driver, the base is big enough for 4D cells and in the middle, the bulb slides up and down, the opening is only a little wider than the bulb base, maybe an extra 3-4mm or so.

Options...
(1) If the LM317 needs Vin = 3V - Vout, where I want Vout=Vf, i'm screwed with 4D cells? 6V Vin and 3V out doesn't leave me with much.

(2) Current limiting resistor. With 4D, I have 6V, if I wanted to drive a Lux 1W or 3W, my Vf will be in the range of 3-4V. Won't I blow the LED if I give it too much voltage? Hmm, i think my memory on diodes has just about evaporated...

(3) DB400/600 a Lux 1W/3W. Maybe a 1W side emitter or a LuxIII would work nicely.

Any ideas for easy heat sinking? I was thinking a copper bolt (if I can find one) or maybe stacking some copper washers. I haven't really worked this part out.

Re: Diamond-flashlight 3W Luxeon PR Bulb? *UPDATE*

Diodes are current devices, not voltage devices. You will only blow it by driving too much current through it. Of course, more voltage usually means more current...

Re: Diamond-flashlight 3W Luxeon PR Bulb? *UPDATE*

utomatoe,

You might be able to get some ideas from this mod ...

It looks like the same lantern as yours. If you can't see the pics (I couldn't), right-click on the pic and select "properties", then copy the URL. Paste it into your browser and add ".orig.jpg" to the end. Worked for me...

Have fun - John

Re: Diamond-flashlight 3W Luxeon PR Bulb? *UPDATE*

Thanks! Lots of ideas for me to play with now. Haha, I guess I should just go ahead and experiment.

Re: Diamond-flashlight 3W Luxeon PR Bulb? *UPDATE*

Diamond-flashlight charges $11 for UPS ground shipping, so the total cost for the 3 watt PR bulb is $31.

Re: Diamond-flashlight 3W Luxeon PR Bulb? *UPDATE*

$11.00 to dliver a $20. item? /ubbthreads/images/graemlins/mad.gif

What I did once, -that worked, was to send them an email explaining what poor economics it really is, to have to pay a 30% premium over what the item is worth -just to get it delivered!

Might be worth trying...and request regular MAIL. (even though they don't officially offer it.

-Rewards in this world usually go to those with the balls to ask. /ubbthreads/images/graemlins/icon15.gif

An email like that loses you nothing, right? Good Luck.