FS: Jibs Linear Drivers

Re: FS: LM1117 Linear Driver - 1.3A Fixed

well rocket689,
you come into a few problems when you use pots...first off, there is the size problem, Pots have such a huge footprint. It would make the driver large and bulky. Second, this driver is primarily used on 445's which have high current draw, at that current, the pot must be able to withstand 2W at least to be stable. 2W SMD pots are hard to find, expensive and BIG. so yea...trust me, i looked into the deal myself, in order to mod jib's driver, but no duece...

Re: FS: LM1117 Linear Driver - 1.3A Fixed

xivlia:
If you're asking because you want to use a host with a 3x AAA insert, the easiest solution is to just solder a wire across the third battery slot - works perfectly
However, you won't quite get enough current out of it to hit this driver's full potential.

Re: FS: LM1117 Linear Driver - 1.3A Fixed

3X 10440 for a 445 build that is supposed to be set for 1.3A is absolutely crazy!! i mean the best 10440 available cant even hit 1A of continous current draw. Also, they will have 350-400mAH capacity so imagine the runtime... like 10 minutes maybe even 5 minutes of full power. (as "full" as 10440's can possibly provide)

Re: FS: LM1117 Linear Driver - 1.3A Fixed

rocket689 said:

Hey Jib, have you ever considered putting a potentiometer on the board for current adjustability?

Click to expand...

doesn't work like that...
its not just a simple thing like ...grab a pot and solder it on there...
pots that can handle 1.3Amps are BIIIGG and expensive...

Re: FS: LM1117 Linear Driver - 1.3A Fixed

That's not all entirely accurate. There are ways of arranging the circuit that make it such that the pot wouldn't need to shoulder the entire wattage. You can put it in parallel and series with other resistors, and create an ability to use 0.5W pots, etc. Of course you don't get the full 0 to 1900 range (you would loose the bottom end in terms of flexibility), but that's not a problem.

Too braindead to do the specific math right now - but it's doable.

However, it's a silly complexity to add when you're designing a driver for one specific diode. Solder bridges are a much better approach (and I think they're what Jib appears to be doing in that mysterious next-gen driver).

If you had the ability to choose three settings - 1.2A, 1.5A, 1.9A, you'd have a perfect 445 driver for 95% of dual-cell setups.

FYI - I'm also pretty sure jib's mysterious driver sneak peak, is setup (based on the resistors he's using) for a 1.9A option. Very very exciting stuff Jib is up to

Re: FS: LM1117 Linear Driver - 1.3A Fixed

Well, i never said it isnt possible but it does add a level of complexity and cost, and size, all of those which goes against what makes jib's drivers so awesome. Running resistors in parallel to the pot will keep the power dissapated lower but even 0.5W pots are still big. I ordered a bunch off mouser and all of them make it difficult to fit a driver in an aixiz module... either way, not something jib wants to do or else he woulda done it.

Now about those solder bridges...I know jib mentioned that some time ago, another fellow on the forum is working on a driver very similiar to what we mentioned. I think he called it the simpledrive or something like that. Except he makes his for "everything" i.e. reds, blu-rays 6x and 12x and 445 blues. interesting stuff.

Im waiting on jibs to work his magic and get us a nice boost driver. Hell i wouldnt give a rats azz if his driver cost the same or a little more than a flex or microboost. Waiting on those to be back in stock is a PAIN!! I would rather get one from jibs. He takes care of us well.

Re: FS: LM1117 Linear Driver - 1.3A Fixed

Agree 100%

Re: FS: LM1117 Linear Driver - 1.3A Fixed

hey rhd, i know you've been quite interested in driver alternatives as well, have you made significant discoveries?

I've been modding led drivers and the ever so sweet njg-18 drivers. DX drivers are somewhat moddable, but other drivers i've found use complex IC's ...reflowing 16-pin ICs have led to only failure...

Re: FS: LM1117 Linear Driver - 1.3A Fixed

This week I'm experimenting with the MIC29302WT, which looks very promising. 0.37V dropout (in theory). Will be a fun IC to play with.

What do you do to your NJGs?

And have you found a decent Buck driver for ~1,750 mA? In theory, that should be achievable with AMC7135s... but I still don't understand why all the AMC7135 drivers lack a coil, but are yet still labelled "buck" not "linear"...

Re: FS: LM1117 Linear Driver - 1.3A Fixed

@ RHD

Thank you for explaining it that way. It makes sense why jib is making them like this. :yh:


Quote of RHD:

That's not all entirely accurate. There are ways of arranging the circuit that make it such that the pot wouldn't need to shoulder the entire wattage. You can put it in parallel and series with other resistors, and create an ability to use 0.5W pots, etc. Of course you don't get the full 0 to 1900 range (you would loose the bottom end in terms of flexibility), but that's not a problem.

Too braindead to do the specific math right now - but it's doable.

However, it's a silly complexity to add when you're designing a driver for one specific diode. Solder bridges are a much better approach (and I think they're what Jib appears to be doing in that mysterious next-gen driver).

If you had the ability to choose three settings - 1.2A, 1.5A, 1.9A, you'd have a perfect 445 driver for 95% of dual-cell setups.

FYI - I'm also pretty sure jib's mysterious driver sneak peak, is setup (based on the resistors he's using) for a 1.9A option. Very very exciting stuff Jib is up to

Re: FS: LM1117 Linear Driver - 1.3A Fixed

Re ^

In fact, to be honest, I think a 1.8A driver would itself be useful in 95% of two-cell setups. Even if you're using it in a host with batteries that clearly won't achieve 1.8A current, you're still getting a "regulated current" - in the sense that you're guaranteed not to exceed the max current your diode can handle.

Unless there's an element I've overlooked, I can't see any fault in using a 1.8A (set) linear driver, with two cells that you know can only produce say 1.3A. You may only get 1.3A, but I don't think that implies that you're out of regulation.

Re: FS: LM1117 Linear Driver - 1.3A Fixed

@rhd
I've switch out the ss14 diodes on the njg-18's with ss34 diodes to allow it to be more stable at 1.6A or so. Plus, 220mF 10V caps also makes those suckers much much more stable. with small bits of aluminum as heatsinks, I managed to get 1.62A STABLE...as in over a perioud of 30 sec, it varries only 10mA. No start up surge, (at least what a DMM can pick up) and stable voltage as well. Only an O-scope can tell how much noise there is, but from my 445 builds, it seems to me like my modded njg-18's are just as good as flex's even though the njg's are constant voltage drivers.

edit: I also tried putting in a smd transient voltage suppressor diode but have yet to succeed. Theres no room for such a large diode (3A current rating). I always get solder everywhere or end up with something messy. I think with a TVS diode in place, the njg's will definitely never fry a diode ever!

I also have been looking at a decent buck driver. I got some red DX 1 mode drivers, but since the markings are all scratched off, and those drivers vary alot, its been difficult to find datasheets and thus, changing components on them is difficult. I did one where i stacked sense resistors to get higher current, but the damn cap blew up on me... go figure... then i tried to replace the cap, but taht just made it a linear driver. I.E. it doesnt buck or boost voltage...it sends out whatever you feed it... weird.

Re: FS: LM1117 Linear Driver - 1.3A Fixed

i made my laser work today...but now it wont work.. the laser is very dim i dont know why its doing this? can anyone help? thanks.

Re: FS: LM1117 Linear Driver - 1.3A Fixed

xivlia said:

i made my laser work today...but now it wont work.. the laser is very dim i dont know why its doing this? can anyone help? thanks.

Click to expand...

Have you checked your battery voltage? Low batteries can make it dim. Either that or the diode is diminishing

Re: FS: LM1117 Linear Driver - 1.3A Fixed

hmm i think the batteries are fine
but i only built it today :S could it be the driver? i may have shortened out something maybe thats caused it? im pretty sure the diode is fine.. is there any way i can test to see if the component are working or not?

Re: FS: LM1117 Linear Driver - 1.3A Fixed

Do you have a dummy load?