Conversion suggestions for 4AA light?

I just got the little guy on the right.



It's a Craftsman 4AA flashlight with a Krypton bulb ($7). Its neat feature is a built-in battery power green-yellow-red indicator. The bulb has a standard PR base, and the lens has a little focusing blob in the middle which gives the light a tight throw.

I'm sure this light can be made brighter. I mean, there are lots of brighter 6V lights out there, right? What kind of bulb should I try?

I've thought of getting that one several times. There's always the KPR103 (3-D-cell) bulb with NiMH batteries, or something like the HPR52 radio shack sells, a halogen bulb. Problem there might be heat damage. The stock PT40 bulb is 500mA so that might not melt anything and would be more efficient, but probably not brighter.

Personally, I'd stick a 2 LED PR module in there and have myself a Turtelite II with a battery indicator.

Originally posted by radellaf:
Personally, I'd stick a 2 LED PR module in there and have myself a Turtelite II with a battery indicator.

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<font size="2" face="Verdana, Arial">Is that okay to run on 4 AA, or would I need a dummy battery?

It's probably the same basic torch as I modified in the thread below:

http://www.candlepowerforums.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=14;t=001055

I've bought a Craftsman version too - and the same mod worked in there too. It had a black body (no blob on the lens), but did have the battery monitoring 3 colour indicator LED. The beam is a bit softer with the Craftsman torch due to the textured reflector - not worse/not better - just different.

The reflector is metal? It looked plastic to me (and smooth, not textured). I'll have to check that.

That's the kind of light I used to make my led dimmer light. Works good in the middle of the night.

4 led dimmer light

Max,
I use a 4 LED PR based bulb made by John B. Great lamp. You can get it in 4.5V version to run on 3 alkalines, or 4 rechargeables; or the 6V version to run on 4 alkalines. Great light. TX

Originally posted by Max:
The reflector is metal? It looked plastic to me (and smooth, not textured). I'll have to check that.

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<font size="2" face="Verdana, Arial">I think there's a whole variety of the same torch (made in China). The reflector on the Target Greatland brand was smooth (no 3 colour led) plastic coated - but metal on the inside. The Craftsman brand one (made in China) that I bought had a textured reflector metal with plastic coating on the outside. I found out it was metal when I tried to cut it with a dremel for my first Star/O mod - found out the hard way that it was a metal reflector embedded in a plastic head.

cheers,
george.

Dorcy makes a single LED light that looks suspiciously similar to the stubby little one on the right. Feeds 6V to the LED, which is resistored and has the "dome" ground to diffuse
the light. Of course, I had to get one (about $12 at the local hardware store, and of course,
I just had to tinker with it, my alternate bulb
uses a scavenged PR base with a resistor inside,
and a cyan Lumileds "spider" LED. Don't yet have a 1W SE, else I'd had tried that too...

Oh, yes, I also committed the ultimate sacriledge and tried out a 6V PR based (gasp) in.... inc.... inc*nd*sc*nt bulb in it. Forgive me....

/ed b in NH

Originally posted by txwest:
Max,
I use a 4 LED PR based bulb made by John B. Great lamp. You can get it in 4.5V version to run on 3 alkalines, or 4 rechargeables; or the 6V version to run on 4 alkalines. Great light. TX

Click to expand...

<font size="2" face="Verdana, Arial">I have the Craftsman light with battery indicator and the black body with a textured reflector.

I've got enough project backlog that I'm in the habit of initially doing quick mods, then later doing the "real mod". For the quick mod I made my own 4 LED PR base bulb with Nichia whites to operate off of 4.5V. I used a file on each LED to create a 90 degree angle so that four fit together very tightly. I filed off the small flange and went a little deeper into the body of each LED. The object was to get 4 regular 5mm Nichias to squeeze together enough to be no larger than the PR glass bulb - so it fit into the flashlight. This did not affect the beam at all. I used four 33 ohm resistors - one for each LED to limit current to 20-35mA depending on battery freshness. For this light I wanted good light and very long life. I also created a dummy battery from a wooden dowel section to make the light a temporary 4.5 volter.

Four LEDs work well in this light and the battery indicator still works OK with only three cells. Given new batteries, it quickly went from green to orange (2-3 hours use), has been orange now for another 10 or so hours, and I hasn't hit RED yet !!

I plan to remove the PR bulb and mount the Luxeon HD white I have with a homemade buck convertor to run at 6V. I have some discarded copper bus bar to make a solid heatsink slug with. This will be a permanent mod and I'll get a cheap one of these lights for the 4 LED PR bulb I made. (See - a simple excuse to buy yet another light )

This is my favorite form factor for a light - it's compact and the right size to grip well due to the slightly pudgy body. The large head allows for a very effective reflector. There's also a lot of room in the head for circuitry. I personally only like lights with click on/off type switches, (as opposed to rotating the head) - so this style light is perfect. My CMG infinity which is now three years old is nearly useless due to intermittent operation from the inferior rotate the head type of operation . Gee, this could start a religous debate - rotate on or click on. Click on/off is clearly the most reliable and ergonomically superior method

- even if it adds a small amount of length to the light. I'm sure there are no other opinions on this....

So far, all I've done is replaced the 4AA 0.5A bulb with a 4D 0.75A bulb, and I tucked a 3D 0.75A bulb into the spare bulb holder. I figured that when the batteries start to die, I could revive the light for a little while by swapping to the lower voltage bulb. Or, the 3D bulb would work well with NiMH.