100 Lumen Tail-clicky 3AAA flashlight, nice flood, $5.47

$5.47 Plus a soldering iron and half an hour of your time.


$2.50 each shipped when you buy 2: LYCKEBY. 9 LED 3AAA tail-clicky flashlight, accepts non-tapered LED's. This is direct drive The color is rather blue and not very bright. I measured 700 mA at 3.70V with NiMHs. Not much to show for 2.6 watts.


$2.97 for 9 Pieces of a 50-pack of White JELED 50K from ebay for $16.50 shipped. These LED's put out ugly color variations and various artifacts, but with 9 together it all mixes up nicely. Installed, the 9 directly driven pull 460 mA at 3.80V with NiMHs. That's 1.7 watts...

According to this thread, at 51 mA the JELED emits 58 lm/W. Using NiMH batteries, I'm running this current at Vf=3.80. That means for 9 LED's, I'm pushing a floody beam of 100 Lumens.

Now since this is direct drive, the light is going to diminish instead of being flat. Sorry, I don't have equipment to measure light output runtimes.

This would be a "don't get too wet" flashlight. There is no seal for the plastic lens, and the button rubber is not compressed, but it is good quality aluminum.

INCREDIBLE

wouldn't using NIMH batteries make it flatter?

infection0 said:

INCREDIBLE

wouldn't using NIMH batteries make it flatter?

Click to expand...

That's the plan. I've been using the mods on and off with NiMH over the past couple days, and they are still very bright.

Good luck on overdriving the LEDs. I had an 8 LED light that lasted about a week or so on nimh till the LEDs started going out one at a time. Most of the generic cheaper LED based lights dont match the LEDs up well so one may be getting 60-70ma and fry thus dividing the remaining current amongst the rest. I recommend about a 3 ohm resistor inline to reduce the current to about 30ma/LED if you plan to use nimh.

There is no good way for the heat to leave. I only use it in runs of a minute or so (looking for something in the basement, checking the thermostat, or lighting up my sock drawer, etc.) I agree some LED's are probably getting more current than others.

The way the board is constructed it's not easy putting resistors in, but it could probably be done by scratching voids between connections and surface mount soldering the resistors. I'll see how long it lasts. I have better 5mm LED's on the way.

By the way, HOLLVIKEN (10 white LED's and 4 RGB) has very white LED's onboard. If you buy this light, you don't need to change LED's.

EngrPaul said:

The way the board is constructed it's not easy putting resistors in, but it could probably be done by scratching voids between connections and surface mount soldering the resistors. I'll see how long it lasts. I have better 5mm LED's on the way.

Click to expand...

Those "better" (whiter) LED's arrived. BestHongKong ultra white 25K. They are great! White, but slightly green if you need to know what way the tint leans.

This time I calculated the current I wanted and modified the circuit, by Dremeling a new pattern in the board with a sharpt tool, then and installing nine 20 ohm resistors, one for each LED. Then I potted in the head so that the heat has a way to flow to the aluminum shell. This time around I'm pushing 240 milliamps total. I have 4 hours runtime and 30 Lumens of light from 3 NiMH AAA's.

Plus I have the scorcher 100 lumen torch described above, still working!