Bright LED

Interesting info. I read the other day that LED's now match flourescents in efficiency. Is that true? Thanks Karl

Not for the one mentioned - that's some 30lm/W IIRC. There are ones in the lab at 135lm/W, but the commonly available 'in the wild' best efficiency is Crees XR-E series, running around $7 for 1W, at

Linear fluorescent tubes are around 100lm/W for the best, compact fluorescents are 50-60lm/W, and conventional incandescents are well under

For small lights, as found in 2AA torches, or under, the LED is vastly more efficient. As a silly example - I replaced my minimag solitare that had been on my keyring for years, with

Ballpark, 12 lumens is the same output as a 'standard' candle. Though flashlights concentrate the light rather better.

Not in $/lumen efficiency. ;-)

Best regards, Spehro Pefhany

I believe that was efficacy and not efficiency.

Ill take the first couple you make, with a 1" OD or has Pitikinny rail mounts.

And a frame squeeze mount ala laser on 1911s

Gunner, Bishop in the Church of John Moses Browning

Political Correctness

A doctrine fostered by a delusional, illogical liberal minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.

Beware!!!! The heat produced by the high power LEDs will have to taken care of. The heat is mostly transfered out the leads, probably surface mounted. Heat kills LEDs just like any other solid state device.

We bid on assembly of high power LED lights and as I recall, there was about a 5" square of special alloy aluminum sheet used as heat sink for 5 LEDs. High heat conductivity epoxy was used to mount the VERY THIN circuit board to the heat sink.

Paul

LED's are good for 50K hours while fluorescents don't last nearly as long. They have a ways to go to compete costwise with fluorescent, but it's a new technology with plenty of room to grow.

These high-power LED's are designed differently. Thermal resistance junction-to-case is about 9C/watt. They do need a heatsink but it's not difficult to arrange. I bond them to the sink with Omegabond 101.

That would be the Church where the Bishop makes others holey, right?

I'll take the first couple I make, and I about never make more than two of anything.

I see that Streamlight does offer a couple of rail-mount LED lights,

You can buy the essential guts of an 80 lumen LED light for 20 bux at Wal-Mart. The MagLED 2D "bulb" with integral drive elex uses a Lux III, probably about 80 lumens. It runs just fine off a single CR123 lithium cell. You have the machinery and skills to make a housing however you want it. Might need to scrounge a suitable reflector, or get a collimator online for about 5 bux.

SNIP

Don, thanks for the nice report. I was wondering when these things would start trickling out to us nobodies. If you are at liberty to divulge your source, may I ask where got yours from?

I have done a minor amount of messing around with the older Luxeons, but have not been following the developments for a while due to time constraints. These things are way cool. As our RCM resident Flashlight Guru do you have any good hints on drive circuitry that you would care to share?

Thanks again. Always learn something from your posts.

AL A.

Two thoughts: 1. I like the color temp, I'm thinking film photos!

1. You know it will fit my XD's rail...I was thinking of mounting a bottle opener on it.

Doubt if I'm a guru, probably just make more noise than others.

I got them from Future. They're now willing to sell them in onesies. The parts I got were U bin, one bin down from the brightest V bin which they probably still only sell in lots of 2K or more. You can probably find V-bin parts from online resellers, but you might pay as much for one of those as for several U-bin parts direct from Future. They buy a quantity large enough to get Future's attention, mark 'em up significantly and resell to those who only want one or three to play with. Not knocking them at all for making a decent profit that way.

It's like PC processors: today's premium part is tomorrow's commodity and the day after tomorrow's surplus. It's a fast-moving technology. Other sources also get them from Future because Future is the sole distributor. Other sources charge higher per-unit prices but Future sticks it to us little guys with shipping charges on small orders when they'll bother with us at all.

There's no "best" solution for drive cctry because what's "best" depends so much on requirements and constraints like size, efficiency, source voltage available, importance of cost, build capabilities, volume, yada yada. I usually use dirt-simple linear current regulators where efficiency and size aren't important, as in task lighting. For flashlights, a lot of folks (including several flashlight makers) seem to be using the Zetex boost regulator chips, ZXSC3xx and ZXSC4xx. They and suitable companion transistors are available from DigiKey. Datasheets and appnotes can be found at

Some cheap flashlights just use 4.5 volts worth of batteries and a dropping resistor. Some really cheap flashlights even omit the dropping resistor and rely on the internal impedance of the battery -- they don't care if the LED's last more than a few weeks after sale. Future and Lumileds push a Sipex boost regulator chip similar to the Zetex chips, perhaps because Future has interests in both companies. I've not used them.

I think Ian Sterling is using a microcontroller though he doesn't seem willing or at liberty to share just how. It could be quite straightforward with enough inductance and a 20MHz microcontroller.

Cost of silicon is crucial to a product design, nearly irrelevant to one-off tinkers like me and perhaps we. Use two or three $2 parts? Oh dear! (Yawn) Packaging is always the greater challenge.

Thanks for the info as always everyone. Karl

Disciples of J. M. Browning have caused many wayward souls to repent for their evil ways. It is said, the mear display of the works of J. M. Browning, can cause a complete change of outlook and attitude in those that have ill intent.

Wes

While Saint J.M.B. never claimed talismanic powers for his works, his followers have found they seem to exert a strong spiritual effect upon those who intend evil toward others.

Indeed, no few malefactors have been observed "getting religion."

Say Hallelujah!!

Gunner

"Liberalism is a philosophy of consolation for Western civilization as it commits suicide"

- James Burnham

commits suicide"

You guys are gonna make me a convert yet! I've had me an "attitude" about JMB's creation for 40 years. I got a very sour taste after barely qualifying with it (one-handed only) at 1000 inches after easily firing expert with about everything else at considerably longer ranges including popups. Then I recently got into a running correspondence discussion with another guy about how semiautos are NFG compared to wheelguns. Hm! So then I did some sums, was surprised to note that JMB's design may actually be as enjoyable to shoot as my .40 S&W polymer pup. He ran some calcs with his fancy ballistics software and confirmed that it might actually be rather easy on the shooter if not the shootee. Nearly twice the weight, 5-1/2" barrel, nowhere near twice the energy or bullet weight, crisp SA trigger action. Hm!

Now I gotta try one again. I may have been playing a flawed tape for

commits suicide"

Nearly all military 45s used in training, were worn out pieces of shit. Most of the actual working guns were on active.

Come on out to California..and Ill drag out 5 or 6 samples and let you play with em. You may be pleasantly surprised..

Gunner

"Liberalism is a philosophy of consolation for Western civilization as it commits suicide"

- James Burnham

commits suicide"

I'd love it, but it's a hell of a commute. I noted four of 'em in the rental counter today, two Kimbers and a coupla Para-Ordnance. They may be clapped out rentals but I could get a feel with them. Today was a shoot with milady (her idea) so I left 'em in the counter -- but I'll be back when Nana goes to visit her granddaugher in a coupla weeks.

We only stayed at the range about 35 minutes, had a swell time. We prefer to go more often for short sessions. Clay, my instructor in the required CCW course I took last March, was rangemaster today. After our shoot I went to him with guilty face and said, "Clay, I have to report an incident on lane 2. While shooting at the top of a target, one of us hit the little clip that holds the target to the trolley." "Who hit the clip?" "Dunno, one of us did." He fixed me with his best stern cop look (perhaps having watched us shoot, he doesn't miss much) and said, "who....hit...the...clip?" "Uh, wull,gawrsh, OK, I hit the clip." He held out his hand, shook mine and grinned, "Congratulations! Those clips are very small targets!" That got a few laughs! (They go thru a dozen of those spring clips a day.)

I'd rapid-fired a mag of head shots. The clip grabbed the head of the sil (B-21 if you care) because the paper wasn't wide enough for a