Can I use 8.4V with this Lambda driver?? <----YES I CAN!!!!

Hi all,


A customer of mine has a few Lambda lights, but since he is out of the game now ( I heard he farms or has a ranch maybe?) its up to me to swap the XML in it for an MTG2. I am guessing its a linear regulator. It puts about 4.3A to an XML off 3 D cell nimh.

My question is can I put 2 li-ions behind it with a 6V MT-G2?





The micro says its Texas Instruments NE556.

This I think
http://www.ti.com/lit/ds/symlink/sa556.pdf

The square one (FET maybe) says LRB103V

The driver has NO components on the back.

Thanks all

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”. :stuck_out_tongue:

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?



Yes I think your correct. Direct drive and NOT a regulator.

You are also correct about the modes. It uses a pot. The pot has an up/down clickie motion for the on off, and the standard dial use for brightness.

I dont want to tear it down any more than I have to, but I will put pictures of what I can get.

It appears that the factory mag housing was used for the pot, but I dont think its grounded anywhere. It looks like a pair of screws hold it in place and that the battery NEG connection is made via a set screw through the neck of the light into the copper heat sink.


Once I have the emitter swap done I will take a few pictures with the head on etc.


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.....


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.

Thanks for the pics! I think you are confused about the MT-G2. When attached to a big heatsink the point where you lose output should be 11-12 amps. See post #16 here: crash-testing a MT-G2 on a copper Noctigon, graph done, mod done and repaired :-)

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 actually dont own one. The only evidence of their existence I am aware of lie in member Bigchelis lumen testing thread at CPF.

Once I found it I asked lambda about purchasing a batch of them, and he did agree that when they were made he would sell me some, but sadly I think he retired before he got around to it.


Post 1187, 1189, 1193 and maybe a few after have some info. Perhaps BigC may still have a few pics?
http://www.candlepowerforums.com/vb/showthread.php?260659-Actual-Lumen-Readings-in-10-5in-Sphere/page40

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 :slight_smile:

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



If Wight or someone else with skills would like to do a layout etc for the group to use as a clone perhaps we can send it to them?


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?

I would think having that option was a nice feature. Since most high powered lights these days are li-ion.

My only real hang up with this driver is that millipede for a micro. I have no way of flashlight that beast, I'll probly just kick someone else a few bucks to program them for me.

I doubt this will help much but I found what I think is another picture of the 2 cell driver in this thread (hard to read anything in the pic). Near the bottom of pg 1.

http://flashlightnews.net/forum/index.php?topic=2477.0

lawallac,

If your interested in doing this



There is really not much to it. All that would need to be done ( if the 2 cell ones are made the same as the 3 cell) is to unscrew the head, and on the back of the neck there is a set screw. Remove that and the heat sink slips out.

No removing or unhooking of any wires would need to be done. All of the components face downward on the driver so pictures could probly be taken just like this.

Anyway thank you for sharing either way man. Nice collection.

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. (555 timer IC - Wikipedia) 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.

Here is an update. I stuck this light in my make shift sphere to get a general idea of the results.

Turn on.......... 3222
30 seconds .....2878
1 min..............2718
2 min..............2552
3 min..............2241

I have to say I am quite impressed with this. Less than a 400 lumen drop from turn on to the 30 second mark, and a steady output even minutes into the test. At 8.3 amp I was expecting the drop from turn on to 30 seconds to be more than that. I guess there really is something to say for a large mass of copper.

I double checked to see if there was really anything more to gain going above 6 amps because previous tests on a smaller heat sink had indicated there was not much. At the 1 minute mark at 6 amps the light tested at 2224 so the 2.3 amps of extra current are yielding almost 500 extra lumens.

Hey, guess who just got an Email from Lambda. Yep, thats right. His sister No wait it was me!

He said that the max for this driver is actually 16V at 30A. WOW huh...

I sent him everyone's best wishes from BLF and CPF and told him how much we all miss him, and that the praises of his work still ring though our hallways..