Black & Decker Spotlight from Wal-Mart 4AA batteries - Photo Heavy - It's Done!

Nope, not an XM-L. Heat is the factor here. Sure there is a heatsink, but it’s cheap cast aluminum EDIT: (Or Die Cast Metal, which would be useless for heat transfer), so it won’t transfer heat very well. Also it’s very thin and has no real mass. The heatsink can take heat from the LED, but after that, there’s no where to go. The outer shell is rubber and plastic (both are insulators), so the heat will be trapped. I will keep it as a lower amp LED, than an XM-L driven at 2.8A to 3A. A Nichia 219 at about 1.4A should be fine. Again, I’m not going for mega lumens, there’s other things than just that, like high CRI LEDs, that give a more natural illumination.

Hey OL sorry for the rapid-fire, scatter brained comments and questioning (thats just how my mind works some times).

I would think carefully about a driver swap to 7135s… they can generate a lot of heat in lights like this that keep Vin > Vf for a good percentage of the discharge. 7135 heat generation can be as much as any plane-jane RLC circuit, or FET with current sense resistors.

I think you should load up some eneloops and run it on HI for 10-15 minutes. If that OEM driver circuit remains moderately warm to the touch… stick with it. I have found 7135 drivers can get painfully hot to the touch the longer Vin remains greater than Vf.

I know, that is a concern for those 7135 boards. There is room in the board area, for a separate heat sink for the board, once the original board is gone, it leaves quite a bit of space for that.
I may try to send this board to another member and see if it can be changed to 1.4A, I just don’t want to put a large die in it like an XM-L and I don’t want to push a small die to 1.8+A, with a poor heat sink that is enclosed in a plastic insulator. As far as modifying this board myself, no way! As bad as I shake, I would have it looking like a figure eight demo derby track in a few seconds, LOL.

So, any of you electronics gurus out there feel like tackling this board and change the High setting to 1.5A, or recommend a different board that would take from 6v to 4.5v input (4AA Alkalines or NiMHs) and output 3v-3.2v @1500ma??

Anyone?

b1

b2

Hm no takers?… Could you turn that POT up to ~1.4A and use that as the lights main setting? So you’d have a main setting and a short burst “turbo”.

R150 is the sense resistor . The easy way is changing it to an R220 or .22 ohm axial resistor not hard to find and measure the current , if too low adding an 1 ohm in parallel to convert it at R180 …with 2,2 ohm go to R200…

Nope, it only ranges from 350ma to about 500ma.

That’s fine, but not with my hands, LOL. That’s why I was asking if anyone with the knowledge and skills wanted to tackle it.

No, the R050 resistor by his thumb is most likely the main sense resistor. It could be a 0.5 ohm or 0.050 ohm resistor depending upon who made it. The R150 may be used for the low level setting.

Yes , you’re right , the sense in the MC34063 is in the positive line , pin 7…also this is a step down driver therefore the emitter is at 2A or more…

You know, if I could remember where I put my memory....... LOL. I already did a Nichia 219 at 1.8A Here!

If I can make a good heat sink, I am just going to use the board I already have. Man oh man, I hate to think what a few more years will do. Probably won't remember that I like to modify flashlights.

I’d try it with the current heat sink. Within reason, extra mass does not affect the ability of a heat sink to get rid of heat. It just delays the inevitable rise in temperature. What does matter most is the surface area of the heat sink and its emissivity. Also, the thermal conductivity of the material. Cast materials can have less that half the conductivity of forged materials because of trapped microscopic air pockets.

Very thin materials (i.e. it bends) can be bad because of thermal conductivity issues. We did a test on a copper heat sink that started out with a 3/8” thick plate. Then it was milled thinner and thinner. It was just as effective at 1/8” as 3/8” (accounting for loss of surface area).

Ha! Because you need a red light to tell you that a flashlight is on!

-Garry

The “cast” part of it, is what I don’t like. That heat sink, as big as it is, only weighs 40grams. I know it won’t conduct well, so I am making a copper sandwich. I don’t have any photos yet, but basically, I am cutting out a section of the heat sink and I am replacing it with a thicker copper plug, with copper plates on either side, to sandwich it in. When it’s done, it will bring the weight to 85 grams. The copper will be what the star backs up against.

It’s done, new photos added in the original post.

looks like you’ve figured it out, but that trim pot is either a variable sense resistor (sort of unlikely unless Hi and Low were on separate circuits) or a variable voltage divider, so that Low is a variable %age of Hi.

A straight LED swap to something a little brighter (219 or XP-G2) looks like the best approach - the driver looks like a Buck driver, which should be pretty efficient and should keep the current draw from the AAs reasonable. That’s one seriously tight spot beam though - great for hunting/ wild life spotting/ dog finding, not so great for camping :slight_smile:

Great! Can't wait for the Nichia beamshots! Let's see a mouseover of the original and then the Nichia!

-Garry

Yes it is a very tight spot. I would say that in it’s stock form, it would be good for wildlife spotting, but after I hacked it, it will be better for all round and the spot will be much larger than before, but I won’t know for sure till tonight.

This thing must not have a fast pwm either. When I went to take a photo of it turned on, with my camera, all I could see was the flickering. First time I have seen that with my camera.

I will try to do that.

Thanks for taking the time to share with us .

Sir !