Steelwolf
Flashlight Enthusiast
I wish I had a digital camera. Sorry, no pics for this till I can borrow a camera.
The essence of this mod is to create a small pocket LED flashlight that is waterproof, not just water resistant.
When I gave some of the Arc-AAA away to friends, I had to warn them that it was basically a Maglight Solitaire but with more constant output and whiter light. And though the "sun" mode burn time is about the same as the Solitaire's burn time, it can still carry on producing dim light for long after the Solitaire has given up the ghost.
However, the down side was that the construction of the Arc-AAA only renders it water resistant. Sure its fine in heavy rain, but what if you go swimming or surfing alot, or like me, get drenched by heavy swells while fishing. Some friends of mine prefer the UKE-2AAA to the Solitaire because of its water-tightness (and slightly improved output).
I looked around and found the Trek/C.Crane and Pelican stuff, but the small ones were not all that small and required either some lithiums or 3xAAA. The 3xAAA one would probably be a little bulky in the pocket as I tried out by taping 3 AAA batteries together. Also, Craig had complained about the difficulties of changing the batteries in his review on his website. The Pelican light has a rubber switch behind, which in my experience, would quickly dry out and crack in this humid weather.
So I took my friend's old favourite UKE-2AAA and drilled out an old bulb assembly to accommodate the 5mm 5.6cd white Nichia LED. I know there are brighter ones available, but that was all I had for the moment. I'll be visiting my local electronics mart (Sim Lim) when the shops open after the Chinese New Year. To reduce light lost to the side and rear, I painted the sides and back with gold coloured paint. I chose gold because the light was already quite blue and I hoped the reflected gold light might impart a slight hue to make the light more pleasant.
Behind the bulb assembly, I built a full SatCure circuit (1 resistor, 1 transistor, 2 capacitors, and a strangely wound inductor), instead of the simplified circuit which has no capacitors. I found that the capacitors visibly increased the light output. This was put together free standing, i.e. no circuit board, each component directly soldered to the next. This was done so as to allow the circuit to fit in a space similar to 1 AAA battery.
After testing to ensure that everything was working, I put a mould in place and encased the circuit with styrene resin (Diggers Casting and Embedding Resin). This wasn't easy as the mould leaked and I had resin flowing everywhere. Fortunately, I managed to get the mould to stop leaking and embed the circuit. This is needed to impart strength to the circuit assembly.
When completed, the entire circuit looks like a AAA battery has been glued on to the back of a standard UKE-2AAA reflector.
The negative terminal remains the brass ring around the reflector and the positive terminal is the bottom of the assembly. This allows the device to be inserted as though it were the second battery for the flashlight and to be activated in the usual manner (turning the bezel). The case was not modified in any way.
Another advantage of this system is that the UKE system replaces the entire reflector/bulb assembly when changing to a fresh bulb. So the user can decide if he wants a xenon bulb or LED. (More likely LED as they are almost equal in brightness and the LED runs longer using only 1 battery instead of the 2 required for the standard bulb.)
I was quite pleasantly surprised to discover that the light output from this circuit is similar to that given by the Arc-AAA with fresh batteries in both. Though of course there is no regulation so the output will dim as the batteries die, but the specs for the circuit claim that it can work to 0.7V, and that would take quite a while to reach.
The essence of this mod is to create a small pocket LED flashlight that is waterproof, not just water resistant.
When I gave some of the Arc-AAA away to friends, I had to warn them that it was basically a Maglight Solitaire but with more constant output and whiter light. And though the "sun" mode burn time is about the same as the Solitaire's burn time, it can still carry on producing dim light for long after the Solitaire has given up the ghost.
However, the down side was that the construction of the Arc-AAA only renders it water resistant. Sure its fine in heavy rain, but what if you go swimming or surfing alot, or like me, get drenched by heavy swells while fishing. Some friends of mine prefer the UKE-2AAA to the Solitaire because of its water-tightness (and slightly improved output).
I looked around and found the Trek/C.Crane and Pelican stuff, but the small ones were not all that small and required either some lithiums or 3xAAA. The 3xAAA one would probably be a little bulky in the pocket as I tried out by taping 3 AAA batteries together. Also, Craig had complained about the difficulties of changing the batteries in his review on his website. The Pelican light has a rubber switch behind, which in my experience, would quickly dry out and crack in this humid weather.
So I took my friend's old favourite UKE-2AAA and drilled out an old bulb assembly to accommodate the 5mm 5.6cd white Nichia LED. I know there are brighter ones available, but that was all I had for the moment. I'll be visiting my local electronics mart (Sim Lim) when the shops open after the Chinese New Year. To reduce light lost to the side and rear, I painted the sides and back with gold coloured paint. I chose gold because the light was already quite blue and I hoped the reflected gold light might impart a slight hue to make the light more pleasant.
Behind the bulb assembly, I built a full SatCure circuit (1 resistor, 1 transistor, 2 capacitors, and a strangely wound inductor), instead of the simplified circuit which has no capacitors. I found that the capacitors visibly increased the light output. This was put together free standing, i.e. no circuit board, each component directly soldered to the next. This was done so as to allow the circuit to fit in a space similar to 1 AAA battery.
After testing to ensure that everything was working, I put a mould in place and encased the circuit with styrene resin (Diggers Casting and Embedding Resin). This wasn't easy as the mould leaked and I had resin flowing everywhere. Fortunately, I managed to get the mould to stop leaking and embed the circuit. This is needed to impart strength to the circuit assembly.
When completed, the entire circuit looks like a AAA battery has been glued on to the back of a standard UKE-2AAA reflector.
The negative terminal remains the brass ring around the reflector and the positive terminal is the bottom of the assembly. This allows the device to be inserted as though it were the second battery for the flashlight and to be activated in the usual manner (turning the bezel). The case was not modified in any way.
Another advantage of this system is that the UKE system replaces the entire reflector/bulb assembly when changing to a fresh bulb. So the user can decide if he wants a xenon bulb or LED. (More likely LED as they are almost equal in brightness and the LED runs longer using only 1 battery instead of the 2 required for the standard bulb.)
I was quite pleasantly surprised to discover that the light output from this circuit is similar to that given by the Arc-AAA with fresh batteries in both. Though of course there is no regulation so the output will dim as the batteries die, but the specs for the circuit claim that it can work to 0.7V, and that would take quite a while to reach.