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

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comfychair
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comfychair
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Final version of the no-name 6XL2 driver

http://75.65.123.78/6XL2/Dsc07066.jpg

http://75.65.123.78/6XL2/Dsc07065.jpg

FET is a recycled TO-263 Infineon IPB05N03LB, supposedly a Rds(on) of 6.1milliohms. I left the 10/10k resistors in place, don't know if they're necessary with this FET but it works and I think if this poor PCB has any more soldering done to it there won't be any traces left.

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Sweet!  Piggybacked PCB for t3h w1n!!!  Big Smile

What amps are you pushing to those 6 XM-L2's...daggum that thing has GOT to be getting warm, let alone throwing some CRAZY light!

comfychair
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I can only guess at the total current, my meters get flaky even with big fat leads. When measuring and the meter showing around 9.5 amps, shorting the leads (bypassing the meter) just about doubles the light output.

The 6x XML2s are in one of the gold Securitylng lights and using one of the red 'JB' drivers. I don't currently have a home for the blue driver.

Ceiling bounce numbers, using Samsung 20Rs, the 3x XML2 T6 3B light does 241 lux and the 6x XML2 unknowns does 273 lux. A stock ~6.5A 3x XML SRK does 54 (yes, fifty-four, lol) lux.

WarHawk-AVG
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Good grief!  Almost 5X the output with just a little tweaking!  Good job!

 

Silly question...short of dunking it in a bucket of ice water, what do you do to keep it cool? I mean that thing must be getting hot in seconds

comfychair
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Heat isn't a problem, not with a user-friendly UI with either 5 (Werner's) or 7 (DrJones') levels available. Level 3 on Werner's and level 5 on MiniMo are both more light than the stock SRK.

comfychair
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I have done A Thing and it has had interesting results...

http://75.65.123.78/6XL2/Dsc07073.jpg

 

Werner's 5-mode on low, left; MiniMo 7-mode on low (PWM value of '1'), right:

http://75.65.123.78/6XL2/Dsc07068.jpg

The beefy little toroid goes between the two pads that originally held the limiting resistors, so it's just stuck between BAT+ and LED+. Still using Werner's 098b which has a lower low than the previous versions, but it wasn't THIS low, and output on high is the same as before. Is it possible just adding a toroid has caused this?

comfychair
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comfychair wrote:

http://75.65.123.78/srk3.jpg

This one is probably not going to work with the add-on 105c. I've removed the gate drivers, going to try connecting straight to the FET's gates, but I'm going to predict it won't work. FETs are AO4468s, specs don't look great based on my limited understanding of things, which is probably why the design is so complex with the separate gate drivers and all the rest; though, why didn't they just use a FET that was a better fit? Who knows.

Gate drivers? We don't need no steenkin' gate drivers!

http://75.65.123.78/driverhacks/Dsc07074.jpg

http://75.65.123.78/driverhacks/Dsc07080.jpg

http://75.65.123.78/driverhacks/Dsc07078.jpg

Works beautifully. Everything - absolutely everything - except the three FETs, can be removed (well, maybe keep the cap where the 105C is picking up the BAT+). Attiny PWM-out is tied straight onto the gates, with the 3 gate drivers removed everything else on the board is inert and not needed.

comfychair
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http://75.65.123.78/driverhacks/Dsc07085.jpg

http://75.65.123.78/driverhacks/Dsc07091.jpg

It does 4.18A, one channel into a single XML2/Sinkpad. All 3 channels tied together to the same LED, around 4.80A. The stock FETs (AO4468) are not very good, at least according to the datasheet, 18 milliohms.

The 3 channels/1 LED thing isn't really representative because of Vf issues, more LEDs will increase the output. I imagine in a 6x light, with 2 LEDs per channel, it'd do around 5A x 3.

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That is impressive. And some sweet looking soldering. Wish I could do that without bweakin it.

Still following this closely.... Smile

~ Ledsmoke ~

Dutch humor:

[quote=djozz]

 I do not think that the BLF-community ben

Werner
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Lol what is/was this copperpipe?
I guess there is no longer a problem with the ground connection :bigsmile:

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The ground... thing is just 12AWG wire, with some copper bits to connect to the FETs' source legs. Originally they got their ground through the sense resistors and the funky-shaped traces, no need for all that anymore.

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Digging the look of that driver.  Kind of Borg meets flashlight driver.  Your work is a little over my head right now, but it seems to be going in a great direction.

comfychair
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Works fine this time. I guess the first try with the stock MCU(-thing) still on the board did something weird to the signal. Just bridging the big sense resistors gets over 4A per channel, I may be sane and boring on this one and just add resistors to get it up around 3.2-3.3A each.

http://75.65.123.78/driverhacks/Dsc07103.jpg

PWM wire connection onto the SRK board:

http://75.65.123.78/driverhacks/Dsc07106.jpg

 

ImA4Wheelr wrote:

Digging the look of that driver.  Kind of Borg meets flashlight driver.  Your work is a little over my head right now, but it seems to be going in a great direction.

This is just like the master-slave thing with multiple 105C boards, only using various different hardware as the slave instead. And the momentary switch firmware is what I didn't have to do this stuff before.

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http://75.65.123.78/driverhacks/Dsc07114.jpg

I'm afraid to try one and find out it's not as good as the ones I already have... :~

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HA, 70N02 does 4.34A, single XML2, single 20R (two 20Rs=4.62A, 3=4.78A, 4=4.86A). Works fine connected straight to the attiny. Bypassing the FET (short drain to GND) with the same single cell/LED gives 4.45A. So it's a good'un. Party

-----

And YES, adding the toroid makes the low much much lower. I checked by jumping across it while running in various modes. Makes barely any difference in higher modes but affects lower modes A LOT.

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Good info in this thread comfychair. Wink
I have some of the 70n03 FET’s from this thread recommended by moviles2. http://budgetlightforum.com/node/21657?page=3#comment-471534.
I have tired to keep up with this thread from day to day and I guess I keep forgetting the day before. Getting old sucks.
I’m going to have to go back and read this all from the start. Maybe once your done comfychair, maybe you could make a “How to” or a “guide” to help forgetful people like me. Big Smile
Nice work you have done here, thanks for sharing.

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http://75.65.123.78/driverhacks/Dsc07129.jpg

http://75.65.123.78/driverhacks/Dsc07130.jpg

Sense resistors bridged, it does ~4.3A per channel. The copper bar isn't a ground bus like the stripped-down version, it's just there to mount & ground the 105C.

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1. The toroids help achieve a lower "low" mode, correct?  Are you using lower driver PWM settings to get this, or with the same PWM setting is the low mode lower?

2. Where can you buy toroids like these?  (Besides harvesting off of existing drivers Wink ) 

Mountain Electronics : batteries, Noctigon, and much more! What's new? 

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Love the way you modded that traditional SRK driver.  Do you plan on using DrJones MiniMo on it?  What is the lowest PWM value you think you can get to work on this rig?

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PWM of 1, with a toroid, gives a hilariously low low. Won't even register on the meter. I haven't done a new build of the firmware to compare the low numbers, but Werner's is using 7 for the low, and even with the toroid it's too much light to really be called moonlight. 1 without the toroid is fairly low, but still not moonlight really.

I don't think the uH rating on the toroids matters much, just that there's something there, and is able to carry enough current to not be a restriction in the higher modes. A little bit of resistance drops the current a lot with the single cell input voltages. To be small enough and carry enough current, it's almost got to be one with multiple conductors, I think. Small number of turns you get with multiple conductors on such a small core seems to work fine. These were harvested from old motherboards.

We're working on nailing down a readily available toroid that ticks all the boxes.

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You have any thoughts on 70N02 vs 70N03?

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Yes, it has higher on-state resistance (.0051 vs .0042) and much much higher gate charge (90nC vs only 40nC), which means a tiny13 would probably not be happy driving it without extra components added in that nobody wants to mess with (gate drivers).

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If its easy and simple to explain, what does the Torroid do?

 

djozz quotes, "it came with chinese lettering that is chinese to me".

                      "My man mousehole needs one too"

old4570 said "I'm not an expert , so don't suffer from any such technical restrictions".

Old-Lumens. Highly admired and cherished member of Budget Light Forum. 11.5.2011 - 20.12.16. RIP.

 

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Magic, would be my guess.

According to Wikipedia, it's like a resistor when current is changing (like, a PWM signal that's on-off-on-off), but a plain conductor when the current is steady. Or something. I think magic is probably a more plausible explanation.

comfychair
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This is the old-style SRK driver, MiniMo, PWM of '1':

http://75.65.123.78/driverhacks/Dsc07134.jpg

That's much brighter than in real life, the camera's trying its best to find any available light.

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Frickin cool.  I haven't seen any srk or triple emitter deliver a decent low, let alone a moonlight.  That looks like a firefly mode or something.  Very awesome.

Thanks for the responses above Comfy.  Much appreciated.

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Red 'JB' driver, 70N02, toroid, MiniMo PWM=1

http://75.65.123.78/driverhacks/Dsc07123.jpg

Werner's 098b (PWM=7), toroid, 2SK4212 FET, left; MiniMo (PWM=1), NO toroid, same 2SK4212 FET, right:

http://75.65.123.78/6XL2/Dsc07068.jpg

Much shorter exposure on the second pic, the background lighting was the same for both pics.

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the geek speak hurts me wee head. I beg of ye, please create a how to/info post on this thread, explaining in everything in plain engrish so us mere mortals can understand.

I have no idea what you have done, but if it makes an srk usable, and is budget-ish, I will take a hundred of ‘em

If you can’t blind them with your brilliance, baffle them with your bullcrap.

The real currency in the world is not money, it’s trust.

comfychair
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The microcontroller, whatever it is, on the SRK-style drivers isn't reflashable, at least not by us. I'm sure somebody somewhere can do it, but I don't even know what the chip is.

The stock modes & UI suck. We can write and flash out own programs for the chip used on the Nanjg drivers, the attiny13a. This is just using a Nanjg driver's controller to run the driver hardware on the SRK-style drivers, with code that works better than stock.

Strip off all the 7135s from a Nanjg 105c, feed it power & ground like normal, then run a jumper wire from the 105c's PWM line that used to run the 7135s over to the spot on the SRK driver. The 105c's brain never knows anything has changed and just does what it's programmed to do. The SRK's driver controls the current to the LEDs, and it never knows it has been given a different, alien brain.

Werner's firmware is: Short press ascends from low to high, five levels (and one level at 0%, which is 'off'). Only turns off by cycling back around to the 0% level. But, a long press descends through the mode order, from high to low. So, with the light off, a short press followed by a long press, turns on in the lowest mode, and then turns off. And a long press followed by a short press turns on in high, and then turns off.

DrJones' MiniMo is similar but has a long press for on/off, and a short press ascends from low to high. Has memory so it comes on at the level last used.

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