Maybe. I think it’s fine; read on and see what you think.

Are we sure it’s not a DD driver? To me it looks like a 555 PWM generator and an FET. You turn the knob and it changes the PWM duty cycle to the FET. https://www.google.com/webhp?ie=UTF-8#q=555+potentiometer+duty+cycle I assume that the thing only has one mode: turn the knob to adjust brightness “mode”.

I didn’t know that Lambda was out of the game. (I think he was farming the entire time btw!) Would you be kind enough to post a teardown of the thing so that others can emulate his work?

What an amazing light. At 8.3 amps it should be pumping out lots of light with an equal amount of heat. Thanks for showing us.

vestureofblood wrote:

vestureofblood wrote:
Well this does work.

I started by removing the XML which is direct bonded to the heat sink. The PCB is only for the = and – wire contacts.

After I machined off the nub for the XML an MT-G2 on a copper star was reflowed into place.

Once the driver was back in place I powered it up, and off we went.

Here is a picture of what the whole light looks like. The head is a 2 part beast. The silver is the factory mag head with some work done to it. The bigger part is the 109 LED harbor freight. An Oring covers the place where the parts were mated.

The driver is direct drive. I tested the current and its pushing about 8.3A off 2 li-ion. I think some resistance may need to be added. I was thinking the point of “no return“ on these was about 6 amp ish right?? So even if the emitter can handle it its a bit of a waste.

All in all I would say that its a shame Lambda is not still in the game. This is a well designed light IMO especially the driver. I could use a few of the boards. Not only this one but just before he left Lambda had a boost driver that could power an emitter to 3 amp off only 2.4V. I could really use a pile of those…..

If there’s actually actually a need for that varapower style driver we could make some. I guess LVP and stuff could also be added without a lot of trouble. In fact, come to think of it… existing designs can probably work for it with only firmware changes.

If you need to limit current you should be able to put a resistor on the hot side of the potentiometer in order to reduce the duty cycle. Or if it’s wired the other way you might need to put the resistor on the GND side. It won’t hurt anything if you get it backwards the first time – you’ll just limit minimum the duty cycle, oops.

The 3A boost driver which operates on 2.4v sounds pretty crazy to me; that’s pretty high current on the pinput side (like 5A or so). I’d love to see some pics of one, hint hint.

I have just read the posts in question. Sounds like the real deal! Too bad he never brought it to market. Like I said, if clear pics showed up it might get cloned. Then again it might not, to be fair – those things can be quite complex based on what little I’ve seen and heard.

Love the Lambda lights. I have bunch of them

The ones on the right are a 2D and (2) 2c XML

That does seem like a lot of Lambda lights! Any interest in disassembling one of your low voltage models and showing clear pics of the driver?

This might help.

http://flashlightnews.net/forum/index.php?topic=2411.0

Hmm, that does look like a good start. Unfortunately I’m not up for much beyond a straight clone, and the pics in that thread are of sanded parts.

It seems that we have two FETs, two caps, one big inductor, and one controller.

very interesting build for sure

Too bad there isn’t a .brd file out there for it

Man I wish I had my old 2C Lamdalights low voltage input Mag. From what I recall it did pull a lot of amps from just 2 NiMH cells to feed the XML 3A or so. Was totally worth it, but pretty much dedicated to NiMH C cells due to high current.

Ventureblood I have a perfect Varapower direct drive switch I can let you have for FREE. You just gotta re-wire the switch to the board and off you go. I will PM you the details.

bigC

That would be fine with me. Once I have clear photos, measurements, and diagrams I can pass it along to whoever. I don’t have a need for an original Lambda Lights Varapower driver to keep.

That said, would there be more interest in a Varapower style driver which also had Low Voltage Protection?

vob, the “millipede” is not an MCU, it’s what’s called a timer. You don’t program those. I guess they are considered a discrete logic component, although I’m not really sure if that’s the proper term. Anyway their function is not programmable, they are a building block for simple circuits. (http://en.wikipedia.org/wiki/555_timer_IC) If I were to implement LVP it would be with an MCU such as an Atmel ATtiny13A (which does need to be programmed).

As to what’s in the picture you referred to, it’s definitely not a 2-cell NiMH driver. It’s just a miniature version of the Varapower DD driver in your OP here.

Lambda wrote:

This unit is actually powered by 6AAA NiMh cells, and performs quite well thank you. I still haven’t received all the parts needed for the 2 cell converter, so 6AAA was all I had around to fit in the 2C space. Running 3S2P they have no problem delivering 3 Amps; if for a some what limited time. But this proto was for proof of principal fitting the control in the C barrel, so getting to explore a VP AAA in the process was just added fun.

Sorry for taking so long to get some pictures. But here you go. Glad you were able to get ahold of Kevin. I had emailed and didn’t hear anything back, glad he’s doin alright.


Lance

Thanks lawallac! Would it be possible for you to post the top markings that are on the components?

The two small black resistors are easily legible, as are the two large yellow capacitors. The large inductor is also clearly marked. What’s left is:

• Large(est) black FET.
• Medium sized black diode next to FET.
• Medium sized 3-leg+tab (SOT89?) component between that stuff and the red/black wires.
• 8-legged component between black and green wires.
• 8-legged component between green wires.

I’ve had some difficulty reading the components but here is what I make of it.

Good work lawallac, thanks!

• Unfortunately I think I just can’t get enough traction on that boost driver with the info we are going to have here. 2/3 FETs are readily identifiable from the markings you posted. The SOT-89 part you marked with a green line is a mystery to me, as is the FET marked with the grey line. I really don’t understand why the boost converter needs so many FETs.
• I assume these lights also feature a pot? If so I also don’t necessarily understand how that part of the driver is hooked up (it might explain some of the extra FETs though..)
• I have not attempted to diagram out the driver.

I think I’ll have to bow out of attempting to clone this boost driver. Maybe I could ask Lambda for help understanding it if he’s willing. Not right now though.

No pot on this light. I don’t know if you had a chance to read through the thread Here , but he did mention difficulty in finding a FET that operated in the 2.4 voltage range. I will have to also peak inside the 2c versions.

Hmm, it’s starting to come together now. A little.

I’ve only skimmed the first page of that thread once or twice. At your suggestion I read the entire thing. Lambda doesn’t say that it’s voltage-controlled, but it is. 331C1 is a voltage controlled (CV) boost controller for 3.3v. I have been unable to find a datasheet, but 501C1 also exists (5v instead of 3.3v). Here is a clear photo of 501C1 from this thread on elektroda.pl. I see some more discussion on 501C1 over in this thread on the same forum.

Voltage controlled seems to be able to work acceptably, at least in some cases. DerWitchel also used CV in a driver (step-down though) for SST50/SST90.

In this case we’d see a little lower current on XM-L2 or a very low (<2A) current on XP-G2, based on djozz’s charts (post #51). Of course MT-G2 or strings of LEDs are both completely out of the picture, but that was really true anyway on 2s1p NiMH – regardless of driver selection!

It would still be worthwhile to me to find out exactly how this driver operates, but I don’t think that actually cloning it will produce great results.

Nice detective work wight. What your doing is black magic to me. 

MRsDNF wrote:

Nice detective work wight. What your doing is black magic to me. 

Looks like the Russians have some different thinking on the subject of those boost controllers. Somebody over on radiokot.ru is saying that it looks like MC33463H in an SOT89 package. Another says ELM92501C-N (well, ELM92xxxx) in the SOT89 package.

The Polish folks thought that it was it was SOT223, but I’d been assuming SOT89. SOT89 has a tab which is flat and connects back to pin2 (same package as our 7135’s). I don’t know much about it, but it looks like SOT223 has a tab that comes out and then bends down – I’d say the pictures make it clear that that is not what we’ve got here. So we’ve got SOT89!

Moving on, the difference between the two current proposals is really just the location of Vout vs GND. They are transposed between the two components. Oops. Looks like the ELM product is only available with an internal FET, we need one with an external FET. MC33463H–XXLT1 still fits the bill I think!

Here is what is inside of a 2C. Tight quarters in there!

I have 2 of these 2Cs. In this one Kevin made me a nice adapter to run an 18650.