[Oshpark] BLF SRK FET v3 (46mm / LFPAK56 / Dual+Triple Channel / ATtiny13A+85)

Flashlight Modding and DIY Parts
67

BLF SRK FET v3.4 HiPower

.

Based on v3.3, but with focus on high current.

Still triple-channel, LFPAK56, Attiny13A/25/45/85 and DEL’s R5.
Adding indicator LED at Pin7 and layout improvements.
I kept the QuadPad to still be able to use dual-channel firmware.

.

Changelog from V3.2

To fit the needs for high current applications:

- 70 LED+ vias without soldermask

- more GND vias

- Wider current path from GND ring to FET source

- better heat transfer for Q1

- Increased GND plane

  • slightly increased bare copper on battery side GND ring

Other improvements:

- Added Ri7 and I7 for indicator LED at Pin7.

- Added 1 AMC7135

- Added a bleeder resistor from BAT+ to GND

- Reduced size of QuadPad to standard 0805 size

- Removed dedicated Rgate, as the gate resistor fits on the QuadPad and can be used instead of a zero-ohm-resistor between FET and MCU

- Redubbed Rmcu to R5

- Marked in/out for LDO

- Just one place for R1 and one for C1

  • Just a resistor in series per indicator LED

.

https://www.oshpark.com/shared_projects/4trVY7MM

.

.

.

.

Schematic:

.

Component list:

- 13A/85: MCU ATtiny13A or 25/45/85; 8S1 (SSU) or 8S2 (20SU)

- R5: Series resistor between VCC and MCU Pin1; 0805

- FET: N-Channel MOSFET at Pin3 or Pin6; LFPAK56

- (Rgate): Series gate resistor; use the QuadPad (FET-to-Pin3 or FET-to-Pin6); 0805

- Rpldn: Pulldown resistor (gate to GND); 0805

- Q1: Single AMC7135 at Pin5; SOT-89

- Q2-11: Up to 10 AMC7135 at Pin3 or Pin6; SOT-89

- D1: Schottky diode (~0.25V) for 1S (4.2V); SOD-323

- LDO: Low dropout regulator for 2S (8.4V) [LDO needs C1 and C2]; SOT-23-5 (Vout is pin5)

- C1: Input capacitor between Vin and GND; 0805

- C2: Decoupling capacitor for MCU; 0805

- R1: Voltage divider to VCC [before D1 / behind R5]; 0805

- R2: Voltage divider to GND; 0805

- Rb: Bleeder resistor from BAT+ to GND; 0805

- SW+: Pad for momentary switch to Pin2

- SW-: Pad for momentary switch to GND

- Tin/Rt1/Rt2/T+/T-/Ct: Temperature sensor

- I3/Ri3/I-: Indicator LED at Pin3

- I7/Ri7/I-: Indicator LED at Pin7

  • *2: Dedicated solder pads for Nanjg Star 2

Notes:

- Rt2 can be used as Nanjg Star 3

- OTC can be used as Nanjg Star 4

- A Zener can be placed on Ct, which is MCU+ to GND

  • A momentary switch at Pin3 can be soldered to the QuadPad
68

Very nice work HQ!

69

Again, very impressive!! Might need a version slightly wider, 2 screw holes, but, you got time for that...

70

Love that ‘Nike swoosh’ for LED- on the Jester!

71

Just ordered a set of 3. Boy these boards are perfect for the MT07 and MT03 lights - they use standard SRK size drivers. LDO and away we go...

Your driver, these lights, and XHP70.2's were made for each other!!

72

I recv'd these boards a while back - no time to try them out though. Realized though a big problem to use them in a MT03 or MT07 -- the batt+ pad needs to be centered and way smaller. Thinking if some way to use it - scrapping off, prying up up a large amount of center tracing, and/or use of kapton tape. Actually I think would might work:

add solder to the grnd ring so it makes contact to the battery holder ring first, preventing contact to the batt+ center pad. Think if I keep the solder really low and kapton tape the outer part of the batt+ pad, that might do it.

Ooops - totally wrong bout this. Forgot about the solid driver retaining ring of the MT03. It fits perfect as-is, ground ring contacts well and the Batt+ doesn't make any inadvertent contact.

I just gotta figure or remember what cap values to use with the LDO, on the C1b and C2 pads... ?

Ooops Again - didn't realize the board layout totally changed from v3.2 to 3.4 - pads aren't even labeled the same... Oh boy... I can figure it all out I'm sure, just gotta figure out cap value again... Might need help from DEL. Let me check back thru this thread as well.

73

I looked at this driver
It is pretty odd that the Temperature sensors connection goes to the output of the LDO and ground

There must be some sort of circutry that disable the FET on the Tin pad and the 2 resistors nearby

74

Why is that odd? Dunno what a temp sensor supposed to get, but sounds like he's providing it 5V, I'm thinking? Suppose it needs a connection to an I/O pin of course, but none are available, which is why it doesn't interest me at this point.

I'm using these as 2 channels with enabling the indicator LED on pin #3 in the MT03 and MT07 - got all the parts nailed down, so will reflow soon.

Using DEL's new C3 and C4 to reduce the spikes the 7135 was getting. C3 will sit on the Rb pad, while C4 is from LED- to ground, so probably will use an empty 7135 pad to bridge to LED-/

75

HQ/anyone! I hit 27K lumens with this v3.4 driver in a MT03! Wow!! Great job on this. Dunno, maybe the Hyperion FET helps a little. Never expected 27K, than means 9K per XHP70.2 in a NW tint! It's totally insane!

I added spring bypass's of 22 AWG wires on all 4 battery springs, and left the double spring on the driver as-is, just transferred them to the v3.4 driver of course. It ripped the 60C temp setting at like 15 seconds - ouch.

Oh! The Humanity!

76

Tom. Are you going mad? Blinded by the light maybe? Nice work. :slight_smile:

77

Any pictures of install or beam shots?

78

WHAT! That has to be 55-60 amps your pulling! :open_mouth: :+1:

Way to GO!! :beer:

79

My MT03 is almost here and I would like to do what Tom E did. Any details would be appreciated.

80

I haven't been able to repeat that reading, but I was seeing 24K-25K, same cells full charge, etc. Still it's pretty awesome.

Ohhh - just thought of it - I swapped the FET to a SIR404DP, think'n it might fix the 7135 problem, but it didn't. It blows the single 7135 - haven't had luck fix'n it. I changed the firmware to do blinks with the FET instead of the 7135, so the blinks work. The 7135 seems to work fine in ramping and mode sets, just would be do any blinks.

I ordered another MT03 II so it's on the way. Gotta check now if I have a spare driver... Hhmm... I did order 3 XHP70.2 P2's from Arrow to use for it - just don't want to take the chance on the XHP70.2's shipped with the new MT03.

Do I have pics? No beamshots, but must have some build pics...

Full set here: photobucket.com Haikelite MT03

81

Awesome!

So who do I need to talk to about getting one of these drivers made for me, I can solder the led and switch wires but dont think I trust myself to do the whole thing yet. Also would I be able to have “Narsil” or Toykeepers new ramping FW flashed on it for me? I have nothing to do that with.

One last thing, will I be able to do lighted switch?

82

I know Lexel is making some of the T_A drivers for sale. Maybe you could talk him into this?

83

Hhmm. Think I'm out of drivers, so if I order some, they come in 3's so I'd have extras. Yes - I got support for the lighted switch - actually mine is using the stock blue and it's a bit too bright, just haven't got a chance to tweak it. If you can wait a few weeks, I'd be able to build one up - doesn't take much more time from doing 1 or 2, or 2-3, etc.

84

Gentlemen,
long time no see

Tom, I knew this driver was in good hands with you. I’m truly impressed.
I implemented DEL’s C3/C4 and refined the design, see next post.
Have them in my hands already, looking very good, just no time for building…

Lexel, the temperature sensor is a direct implementation from RMM’s v2. I never used it myself, just kept it in the design. As far as I understand the sensor itself has 3 pins: T+ and T- are its power supply (hence T+ to the output of the LDO) and Tin is the sensed value. Tin is fed into the Attiny Pin3 through a 2-resistor voltage divider (Rt1/Rt2) to get the voltage down to a level the Attiny can evaluate (probably below 1.1V as for the LVP input at Pin7).

But now let me introduce you to v5.
I heard Photobucket is not the same anymore… Interestingly all my pics still show. I keep my fingers crossed, but I need to get a different hoster.

85

BLF SRK FET v3.5

.

Added C3 and C4
Rearranged LED+ vias
Still focus on High Current :wink:

.

https://www.oshpark.com/shared_projects/BFX7d296

.

.

86

Great to see that it’s still being actively developed! It looks good!