Started my XHP-70 flashlight - EDIT: complete redo

The HX-1175b can drive a 6v emitter with 3s and 4S li-ions. RMM and others have had issues with it blowing 1S XM-L2's over like 5 amps.. I don't know if that is because it was bucking all way down to 3+ volts or if it continues to ripple at higher Vf's. I've driven 1S MT-G2's beyond 12 amps without issue, but we all know that MT-G2 is one tough hombre.

Did I read that right?

you have driven an MT-G2 over 12 amps with a single cell? aka 1S
did you use a boost driver to get the voltage up?

I guess it was an IMR/INR cell?

I think in this case the 1S refers to the led. The driver is buck and is fed by 3-4 series liion cells.

^ RBD has it right. 1S emitter driven by 3S or 4S cells. No boost ability. Sorry for the confusion.

The driver's flyback diode is only rated for 10 amps. So I recommend only driving up to that level. That would be equivalent to about 5 amps with the emitter in 12v configuration.

Could a hobby charger be used to charge up the packs you plan to use by just connecting the positive and negative terminals?

That enable adding a port and charging in light if you didn't want to pull the pack often You could just also solder the tabs for a real good connections. I'm asking because I have a couple of these battery packs too, but no pack speciific charger for them. I do have an Accucell 6 though.

Most of these types of packs have a tab for temperature sensor. It would be cool if that could connect to the hobby charger too. I'll give it a shot in a bit.

how about using this driver for the LED?

wasn’t entirely sure how much amps you need but a regulator like this should work?

^ That does seem like an interesting idea. Maybe 2 of them. One for each channel going to the Emitter. Could have external pots for them to control current.

Hobby Charger Update: The pack can be charged by a hobby charger just connecting the Pos and Neg terminals. All 3 banks fully charged to the exact same voltage. Don't know if that is due to internal balancing circuits or just luck due to new cells.

It appears that the center terminal between the Pos and Neg terminals is for the temperature sensor, but I'm not sure how to connect to my hobby charger since it has 3 wires (Red, Black, and White) for temperature monitoring.

The battery pack has some other terminals that I don't know the purpose of. No voltage measures at them.

It’s possible the eBay buck regulator is not current controlled. I. E. You can set the current and voltage for a given input voltage with the pots but if input voltage changes as with a draining battery, then both output current and output voltage might change. I don’t know for sure and they sure are cheap but you might consider testing one before building the guts of the light around it. It might work anyway but just not maintain regulation. Or I could be full of it, I often am.

I am waiting on solder paste to flow the emitter. I will then take some reading of current draws and post them here. It looks like I will have to rethink this setup somewhat (I figured I probably would)

I restarted this build from scratch, Using black ABS and eventually a buck driver.
I posted the changes in the OP. The light is finished except for installing the driver

Nice changes. Looks good.

PM'd you to work out the details on driver specs.

Nice build!
The Ultrafire name drawn on should give it and extra 20,000 lumens.

I think I sharted myself from laughing so hard !! :smiley:

I was in a rush last night when I skimmed the new OP. Like the two above, the Ultrafire logo was just too funny. But I have to say, this shorty version of the light looks damn good. And, it appears to have a actual functioning anti roll feature with stable tail standing capability. I likey!

That's a wild build! Very nice looking light when it's done. Polishing the plastic really made it look good!

Well done.

08/14/2015
I updated the end of the OP with info on the newly installed driver with pics and beam shot.

What a nice looking driver. Do you think ImA4Wheelr will do a group buy on them?

Both beams look good and it shows what the difference between 42 and 70 watts is.

Looks good dchoman! Was starting to think you permanently parked this project. Just when the suspense wasn't killing me anymore you pull me back in! Is the UI growing on you yet? The FW is JonnyC's Star Momentary modified by Tom E for strobe.

At 7amps, the driver doesn't need the heat sink augmentation. The heat sink augmentation is the large copper adapter disk and the 2 copper tabs covering the large fly-back diode and a portion of the current sense resistors. The Fujik is there more to protect the MCU and air wires from shorts and breaking. I augmented the heat sinking in case dchomak should ever decide to really soup this light up by adding more current sense resistors. I've taken this driver to 13 amps with MT-G2 and at those currents the augmentation is needed. Someday, I may have to short the resistor bank to see what happens with this driver.

In the future, however, we should have the ability for the Attiny25 to throttle the current back and forth as temperature of the light changes. Then, heat sinking the driver will be desired to have a faster response time.

I won’t be changing anything about this driver soon, it is perfect just the way it is. All lights should have a UI like this!
In fact when I was about to shoot the beam shot I used the moonlight mode to find the camera I had laid down in the grass as I was in total darkness at the time. Right now, this is my favorite light :slight_smile:

I don’t know, YOU ask plead with him :smiley:

This light throws a little better, but I don’t think it puts out that much less light. The law of diminishing returns, you know. Even though the reflector of this light is smaller, it throws better than the Sleeper. The effective reflector of the Sleeper is really a small section in the center. The rest of it is just the vestige of an old design for an incandescent.

Now I’ve got to put one of these XH-P’s in a larger reflector!

Yep. Thats what I was looking at the law of diminishing returns. Saying that the components will affect the result as well as we all know.

Just rambling now but I'm building more lights now at lesser currents to suit different needs as in testing without any measuring devices other than my eyes and a tree at about 100 meters away found that an XPG-2 at 2.2 amps in a tiny reflector will light up the tree as well as my original stock standard, never missed a beat Trustfire TR-3T6 that when new blew me away with how much light it through out into the stratosphere. How times have changed in a short period with the efficiency of new components.