Harbor Freight Flash Light Mod

[Jack Crow]

Hi all,
You know those Harbor Freight flash lights.
The ones that they have constant coupons for.

They hold three AAA cells and support 9 little LED in it.

Yeah that one.

Little problem.
There is no voltage control in these lights.
All the LED's are in parallel.

The battery holder puts the 3 AAA cells in series, so that comes out about 4.5v.

Put the light on the variable bench supply and it starts to suck current hard at just over 3 volts.

3.0v 90ma
3.2v 160ma

The current goes up from there.

So you can see this light at 4.5 volts is a battery burner.

Then I got the idea.

3d printed a new battery adapter.

So rather than beat up AAA cells I reworked the thing to run on one 123A cell.
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The terminal voltage on my cells here is about 3.27 volts. (these are old cells)

Print up the adapter and use a 3/4 inch screw to make up the center conductor. 123 cells are much smaller than AAA cells.
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Stick this in one of my lights and it works!
Ran it for an hour and the LED's did not dim.
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Keep it safe
Jack Crow

[Mooselake]

Cool! Even up here, 200 miles from the nearest Horrible Fright, I have several of those laying around.

For small flashlights I've gone to the "Cree Ultrafire" ones, like random picked examples. I usually get a handful or two at a time from eBay or the big rock candy mountain for a lot less, or on specials from the big A. They come in a multitude of claimed luminary output, don't know if that's marketering or they really do range in brightness, but the claimed 7W version is plenty bright. Here 20 miles from the streetlights I keep one in my jacket pocket, plus bedside table and the usual other go-to places for when the lights go out.

Kirk

[Jack Crow]

Boss,
Don't know what to say.
That Cree lamp looks very good.

What I have is crap by comparison.

Because things are not going well dollar wise, I tend to follow the path of "if it's free, it's for me" school.
The HF lamps are in that range. They will do for now.
At the moment I have three white light lamps converted.
One for pocket duty.
One on the bench.
The third I use at bed time so I don't turn on a room light and wake up the wife.

Ran an informal test, and got about 3 hours of run time on elderly batteries. I think that is astonishing considering the OEM cells tend to burn down very quickly.

The plan is when I get paid this week, to order a fresh box of 123A cells, that way the batts come in at about $2 each instead of the 6 bucks at the local wall mart blister pack.

Also pay a visit to the HF up the road and get a few more.
Gift a few out and get some feed back.
There is a Mormon missionary team that lives about three doors down.
I don't understand them but they are good kids.
I know that they don't earn much.
So Im thinking to gift them some "free lights".
Will get some good answers back as to how they work in the real world.

Did find out something weird.
Same factory produces a UV lamp. Same metal work and circuit board with different LED's for the new frequency.
In use, it's hard on the eyes, but handy for picking out liquid damage on circuit boards.

Have one on the bench here and at the day job.
Seems they were cheap from Amazon, five for ten bucks or some such.
The mod did not work with them very well.
Seems the UV led's need more voltage.

That is the follow up from this end.

At this writing Tuesday 3-12 at about 2100L we are getting a slush/snow combination.
The dogs were must unhappy to see it.
I was not thrilled either.

Later boss
Jack Crow aka Radio Mike