So I somehow managed to create a 70N02 Roche driver awhile ago. Even though I haven’t really found myself interested in straight DD yet and I don’t have an Roche F6.
Still interested in one Comfychair?
Joke? There should be no footprint issues, this is a 20mm 2-sided driver. 70N02 fits on a 17mm driver, surely it must fit on a 20mm driver even with a small microswitch added? The IRLM2502 is has vastly inferior RDS (on). It’s a “baby” FET.
You just put the MCU and most support items on the bottom and the FET on top.
The 20DD is just a 17DD, with a bigger OD. Plenty of room for the switch without changing anything or moving parts to the battery side.
Warhawk, that switch is far too big, it needs to be one of the 'half height' rectangular switches, specifically the one I linked to or one of the same package size/format. The driver compartment on the F6 is extremely tight and the switch fits into a little machined pocket in the side wall. It has to be the same outline as the one on the original driver.
The stock driver isn't that bad really, it just has some annoying quirks. Could be better (can't everything be better?).
It only has 3 modes but they are nicely spaced, the low is sufficiently low, but a long-press-for-on/off UI really should have memory, otherwise what's the point? It always turns on in high mode whether that's what you want or not. The long press duration is reasonable, unlike the DQG 26650 (three seconds?? you gotta be kidding me! It's easier to turn that one off by unscrewing the battery tube, truly annoying.). And the output is pretty good too - it doesn't lag far behind a Convoy S3 using a 17DD & the same 10* TIR. It's driven hard enough it'll get HOT if you run it a while. The low voltage warning LED is interesting, I guess, but is it practical to look down at the light every so often to see if the LED's flashing red at you? There are better ways to handle it, in the firmware.
The biggest improvement by far is adding the TIR, the driver would just be a bonus.
The tailcap is pressed in, there is not cap to unscrew…you could knock out the plug…but getting it back in without a press might be difficult
hmm…this driver looks like a buck circuit (the big coil gives it away), might be able to resistor mod it, also it has mode memory ONLY if you leave it in the mode you want for a few seconds…if you change modes then shut it off quickly it starts back up in next mode memory…a flaw in the programming
Only other way to increase power would be to get custom hardware builds…I believe people are working on them
Well, its done. Just not sure if it might be a little tight for some. Goals were to fit as much on the top as possible (so it can just be reflowed on a hotplate), use an ebay switch (so that no one is forced to do a mouser / digikey order just for a switch), stick to 0603 0805 & include indicator leds.
Lost interest in trying anything different.
~ Edit~
0805. Would have been easy if I used 0603 instead.
Would you be willing to put the IRML2502 on it…not as beefy as the 70N02 on it…plus do you really need 12A on a single emitter?
Besides 4~A would be ALOT for this setup…not a whole lot of meat there to soak up that heat…with the ATtiny and 4-5 modes lower than wide open would definitely make it alot more versatile? Star or minimo or (Tom E Omni Mech build of luxdrv[well…I dubbed it OMNI MECH because it has 25 different variants in it])
Mine's from FT, ordered mid-April. http://www.fasttech.com/products/1658300
Long press for on/off, always starts on high mode, quick double click while on gives strobe, single click alternates from strobe to SOS, long press returns to non-blinky modes.
Maybe you misunderstand? The purpose of a DD driver is to step out of the way as much as possible (low resistance) and then use PWM to reduce current for lower modes. You don’t “need” 12A, 75A, or anything else for this application, you need low resistance. The maximum output will be determined by the combination of:
total resistance of the circuit (FET, springs, wires, etc)
Vf of the LED
and voltage sag of the battery
If you were to design a DD driver with the intent to use a high-resistance FET you’d be better off designing a linear driver using AMC7135’s or other linear regulators.