My first mod: the 3-cubed

greg_in_canada

Flashlight Enthusiast
Joined
Jun 7, 2004
Messages
1,146
Location
Saskatoon SK Canada
I call it the 3-cubed because it has a Lux3, is powered
by 3 D-cells and has 3 brightness settings. 3x3x3 = 3 cubed.

It's based on a 3D maglite with O-sink and a Lux3 from
luxeonstar.com

It's direct drive with 3 resistor values selected.
The high setting has 0.6 ohm PTC resistor in series with
the LED. Low has a 33 ohm plus the 0.6 ohm. Medium has
12 ohms in parallel with the 33 ohms for an effective
resistance of 9 ohms.

The PTC resistor is actual a pair of small halogen
bulbs in parallel. The filaments are barely glowing
(dim red) so they should be fairly shock resistant.
The cold resistance is 0.2 ohms and they measure 0.6
ohms when the LED is on high. They are located between
the O-sink and the factory switch. That is why they
are in series with all the brightness settings. I used
them partially to be clever and also because their
resistance will drop as the battery discharges and the
current goes down (so there will be more voltage for
the LED).

Now for a few pictures...

1) The tail cap and the switch (a 3-way light switch
for a lamp.
tailcap_and_switch.jpg



2) The tail with mounted switch (and pushbutton guard)
to protect the switch.
tail_with_mounted_switch.jpg



3) The spring before and after mods (to make room for
the resistors and wiring in the tail). I used a Dremel
cutting disk on it.
spring_before.jpg

spring_after.jpg



4) The bushing (insulator) used to isolate the battery
minus from the spring (so resistance could be added in
series in the tail).
ground_bushing.jpg



I measured the current with fresh Energizer D's: Low ~50 mA.
Medium 160 mA. High 800 mA.

The beam is quite clean. Better than my EverLED maglite
(before satin tape). I borrowed the lens with the Scotch
Satin tape on it and the beam is perfect. On high the
colour looks pure white to me. On medium and low it takes
on a greenish tint.

To do: the apparent brightness jump from medium to high
is bigger than from low to medium so I want to increase
the medium setting current. Also need to sputter my
reflector.

Other than that I'm very happy with it.

Greg
 

jtice

Flashaholic
Joined
May 21, 2003
Messages
6,331
Location
West Virginia
Very nice work.
Thats a nice switch you used there, seems very small for a regulat lamp switch, good find.

You just made yourself a very useful light.
 

greg_in_canada

Flashlight Enthusiast
Joined
Jun 7, 2004
Messages
1,146
Location
Saskatoon SK Canada
Thanks.

I first got a similar switch (but it had a longer
shaft) from Radio Shack. That's why the tail cap has
a D-shaped hole in the one photo. But I broke it while
trying to shorten the shaft. I was happy when I found
this one because the shaft is brass rather than plastic
and with the shorter threaded shaft it is almost hidden
by the guard.

Greg
 

BC0311

Flashlight Enthusiast
Joined
May 31, 2003
Messages
2,488
Very slick, Greg. /ubbthreads/images/graemlins/thumbsup.gif I really dig that switch.

Britt
 

greg_in_canada

Flashlight Enthusiast
Joined
Jun 7, 2004
Messages
1,146
Location
Saskatoon SK Canada
I bought it at Rona (Canadian version of Home Depot).
I can tell you the manufacturer if anyone is interested
in using one in their project.

Because it's a tri-light switch I actually could have
had 4 brightness levels. The switch off position would
be the dim, switch A position would be medium1, switch
B position would be medium2, and switch A+B position
would be high. Basically how as a light switch you
get off, 50, 100 and 150 watts, but here is the low
position.

I did some measurements of my D-cells and it was really
hard to get that 50, 100, 150 ratio due to the battery
resistance. Because of that the brightness ration would
be more like 50, 90, 120. Not much visible difference.
If I were to make a flashlight that ran off Nimh cells I
would go that way.

The other problem with the 4 settings was that all the
resistors then have to go in the tail. Tricky when the
high setting R is about 0.8 watts, the medium is 0.5
watts and the low is 0.2 watts.

Greg
 
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