Mag + DC-DC + Luxeon Star
"The Hydra XP4"

User Modification: Hydra XP4 Mag 2-D to Luxeons + DC-DC
("The Hydra"), $200, see below for availability & additional info.
Manufactured by Kevin Fritz ("Lambda" on CPF)
Last updated 06-08-02

Eyeballs swollen and distended.
Clusters of bright, round afterimages.
Temporary blindness.
And a case of "toilet tongue" so severe, the casting director for National Lampoon's new movie "@*$%! You and @*$%! The @*$%ing @*$%! Too!" called and wants you to play the lead role.

These are the symptoms you can expect if you do with this flashlight what the typical flashlight user does to any ordinary flashlight when they take it home from the store. That is, aiming it at your face and pushing the button. Well, OK, maybe not the swollen eyes part, and probably not the telephone call. :)

The Hydra XP4 started off as a 2-D cell Mag Lite. The Mag was disembowelled, and then "reembowelled" with four super bright Luxeon Star emitters, four independent DC-DC converters (one for each Luxeon), and four sets of Luxeon optics, precision-aimed to produce a single, perfect, and super-bright beam of bluish white light. The tested unit came set up to operate on two different battery configurations: 3 "C" cells for extreme intensity, and 2 "D" cells for a much longer battery life with only a slight reduction in intensity.


The Hydra looks a lot like a 2-D cell Mag Lite on the outside, and it turns on and off like one. But it is *not* focusable, and you should *not* try to rotate the head, as that may damage the optics of the Luxeon Star LEDs inside. The head is affixed tightly, so it won't unscrew with normal effort - so if you forget and try to turn the head anyway, you'll notice it won't move. Stop right there and you'll be fine.

To turn it on and off, just press the rubberized button on the barrel. It has a tactile "click" feel to it so you don't have to actually look down to see when it goes on and off.

The Hydra is set up to use two different battery configurations: the original 2 D cell setup which the Mag Lite was made for, and a 3 C cell setup that allows for a bit of extra brightness. A spring, a length of PVC toilet pipe, and a rubber washer are included, to be used when you run the 3-C setup.

For 2 D cell operation, just unscrew the tailcap, insert 2 D cells in the barrel button-end first, and screw the tailcap back on.

For 3 C cell operation, unscrew the tailcap, pull the large copper spring off it, and push in the smaller chrome spring. Then drop the rubber washer down the barrel, followed by the toilet pipe. Now you can slip in 3 C cells and screw the tailcap back on. The purpose of the pipe is to allow the smaller diameter C cells to be used in the D cell flashlight body. This is a very simple, inexpensive, and elegant solution.

Being loaded with "C" cells.

As with other CPF member's modifications, this one appears very professional, and it looks like the flashlight was supposed to come this way. When you look at the business end, you'll see a cluster of four transparent, cone-shaped "lenses" and a silvery colored epoxy covering the rest. Under that specially-made, thermally conductive material lies four Luxeon Star emitters and four DC-DC converter circuits; each connected independently to its LED.

That's it on the right, with the 4 cone-shaped collimators.
It has a very retro, "Jetsons" look to it.

It is clear that Kevin took great care in making this flashlight. There are no fingerprints on the Luxeon collimators (those things pick up fingerprints so well they should be used on CSI) and everything is assembled properly and with no loose parts or rattling. The components making up each individual Luxeon + converter assembly are all driven under their rated specifications, so there is no great danger of component failure like there might be with an overdriven light. When left on, it barely becomes lukewarm. This is in part because the components are under-driven, and in part due to excellent thermal management. Between the hefty aluminum body of the Mag and the liberal use of a special thermally-conductive epoxy, there should be no worries that something might be running "hot" inside.

The Hydra and its nearest competitor, the ElektroBlaster.
The Hydra is the brighter of the two. From ~10 feet.

And from 12" on the usual test target.
Over 500,000mcd (at 12") on used batteries.

The beam quality from the Hydra really surprised me. Instead of four seperate spots, the beams coalesce into a single spot within the first 7 or 8 inches and stay that way even when shone at a more distant target. This is better than a lot of other multiple LED flashlights which project multiple, distinct spots onto the subject (wall, suitcase, vase, toilet, etc.) no matter how far away from the subject you move.

scope trace
Here you can see the output of the DC-DC inverters.
Note how all four waveforms are almost perfectly in phase with one another.

Unit was built and provided by Lambda (Kevin Fritz) of Candlepower Forums. The original flashlight was a Mag Lite. Neither Kevin nor myself have any affiliation with Mag Instruments. Unit was received approximately 06-01-02.

UPDATE: 00-00-00

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