Toroids and MOSFETs and firmware, oh my! (aka:'Tiny13+N-FET=???')

All those shown have got to vary wildly in their uH ratings, but give similar results in calming down the lower PWM levels.

edit: Tested & working with a modified version of luxdrv 030b - ramping deleted, mode levels of 1,3,9,28,85,255.

Nice. I'm guessing the tab on the back would normally connect to a heat sink and ground. I take it, I'm guessing wrong?

Nope, not ground, the tab is for LED-.

G = Gate (the control pin/PWM pin)

D = Drain (negative wire from the load, here that's LED-)

S = Source (battery ground)

It goes between LED- and ground just like a 7135, except it doesn't limit itself to a fixed current. Whatever your cell can deliver is what the LED gets (minus a tiny amount from the FET's internal resistance, this one is around 0.0045 ohms).

Now that you say that, it does seem that the tab has an emitter wire on some drivers. Just seems like a good place to get the heat out. Thanks Comfy.

Yeah, glued on upside down with JB Weld, and flattening the legs and rebending them is probably a bit outside the intended design parameters, but you know... :evil:

At least it should be easy to solder a nice piece of copper to it.

It doesn't get hot though, on any mode. It might, in the other versions using the inductors since (I think?) in that setup the FET spends more time inbetween fully on and fully off, which is where FETs can get a little unhappy and start making some reasonable amount of heat.

A copper plate wouldn't help here anyway, since if the tab touches anything that could carry heat away the FET is bypassed altogether (LED- to GND).

Correct me if I miss something, but at say 5amps and an internal resistance of 0.0045 ohms, it will only generate 0.1 W, that will easily dissipate through the connectors.

So.. this is the thread that lead to the FET driver RMM is now selling?

Yes. Except I'm not selling it (yet). Comfychair's work was really what brought this all about in the first place. DrJones & Werner have provided excellent yet simple free firmwares for anyone to flash their own drivers.

So you are currently just selling the parts?

That's correct. I need to do some more testing before selling a complete driver, but it has been flawless so far with MT-G2 and XM-L2.

Is Werner's beta published anywhere? I've heard it alluded to in several threads.

That's the only way I will get a copy of it because he will demand $64K if I ask him for it.

minimo works with the momentary switch/FET drivers and minidrv with the clicky/FET drivers. luxdrv is probably better a better starting point for the clicky drivers, since it's got low voltage protection and the battery monitor mode, other modes can be changed/added/deleted.

I don't know what Werner's plans are for his version, I wouldn't want to speak for him. I tested several versions along the way on a range of driver hardware he didn't have access to to see how it behaved.

I received some 07N02's today. Yea!

I don't understand why folks aren't more excited about what is happening in this thread. To me, it's big news. That neat looking driver up in Post 152 would need a whole bunch of pain in the arse 7135 chips stacked up, if not for that FET. They would also rob some voltage (can't remember .1 something volts) and therefore more wattage too. This is just too cool.

Well, if I could understand what to get excited about, maybe I would. Post #152 is a pretty picture for sure, but if I can't understand it's function with advantages/disadvantages, and can't dupe it, then it's nice to see 1 or 2 guys are having fun, but other than that, it's meaningless to me.

I'm thinking it's a direct drive, but exactly the same program as you used to control the 7135's, so using PWM's to slice the direct drive down by percentage. So for example, if you can get 100% at 6A, then lower modes are scaled on that 6A -- just like a amp limited 7135 driver? So basically you got a East-092 driver but that can be custom programmed?

I guess I'm not sure what's goin on: a work-in-progress, or is it done? If it's done, I think someone needs to summarize it, maybe start a new thread to explain what exactly it is and hopefully info on how to dupe it?

No offense meant here - really didn't want to post anything, but it does sound amazing, I'm just not getting it.

SRK 7135 driver, 32 of the (350mA per chip[more if you use the 380mA versions]) 7135 chips to deliver 12A, FET board, 1 FET delivering the same or more...plus still retain the ability to have proper PWM for lower modes

Simplicity, instead of 2-8 7134's you have one bit honkering powerhouse that does the same, think of all the space saving if you use a chip just a bit larger but can deliver 10x the power

Yes sounds exciting, but I'm not seeing how to accomplish this exactly. So, you are saying it's a direct drive driver, like an East-092 that can be programmed? Any difference? If we had an East-092 driver with an MCU that has source code, and ability to re-program, is this design the same or better?

I guess then that is what you can think of it as an East-092, but you can get different max capacity FET’s, ATtiny is programmable, we have the code and many .hex files