BLF Tiny 10DD and Tiny12DD

Flashlight Modding and DIY Parts
83

That’s actually the case with all of the FET and 7135 drivers we currently have.

84

I also have the same question that pilotdog had in post #79 above re. 105C. More exactly, can I pull the MCU from one of these and use it, as-is, on this BLF10DD:

http://www.fasttech.com/products/0/10001751/1127403-8-amc7135-4-group-25-modes-led-flashlight-driver-c

85

Hmm, you’d think that someone (including me) might have answered that. The MCU is definitely no problem. You may use any standard Nanjg firmware w/out modification.

The other parts are all going to be tight but should fit AFAIK - I haven’t built any of these. AFAIK these are 0603 pads and of course the parts on the 105C are 0805 parts, so they sit right on top of the pads.

EDIT: I just checked your link. That’s not a Nanjg product, so who knows. EDIT2: the answer is no.

86

wight,

Ok, thanks for that info.

What about this one:

It says “ATM…” on the top of the MCU.

FYI, I reason I’m asking is I’ve had a couple of these boards for awhile, and finally decided to try them and am trying to scrounge parts to do that.

Thanks again,
Jim

87

That one’s fine.

88

wight,

Ok, thanks.

Looking at the board and also the parts list linked in the BLF15dd thread (BLF15.17DD Info Thread - Reference), the parts list has 3 resistors, a 19.1K, and 4.7K and a 130 ohm.

Which of those is R1, and which is R2?

Also, where does the 3rd resistor go?

Thanks,
Jim

89

As of the latest version, “v1.0”, the 130 ohm resistor is no longer used. 19.1k is R1, 4.7k is R2.

90

Hi,

Ok, thanks. I won’t be able to get to this tonight, but will try tomorrow night.

91

yes

Just unsolder it w/ a solder rework station, plop on the BLF10DD/12DD and voila…you have the exact same modes as the 105C on the much smaller board, you don’t have to reflash.

92

Thanks.

Question: What is the Schottky diode (D1) for?

93

Reverse voltage protection. Bypassing D1 is fine (you lose reverse voltage protection), but you must reflash your firmware with adjusted LVP values or LVP will be very wrong.

94

Thanks (again :laughing:!

This is going to sound like a weird question, but would this driver even work if I used this FET temporarily:

I’ve been scrounging around my junk box all night, and that’s been the only thing close to a MOSFET that I was able to find thus far. It’s a SOT-23, but I guess it’s the “regular”/non-micro3 SOT-23, so is it too large?

Also, it’s Rds(on) is quite high, but I was just wondering if I could use this until the one I ordered from Digikey comes in, just to see if the driver works?

95

I don’t think it will survive long. VERY LOW Continuous Drain Current

You can solder a normal SOT-23 on micro3 SOT-23 pads, you just have to bend the legs in a little bit, I believe C_K found that out when he ordered a different MOSFET and it came in a little bit bigger size

96

Yes, I saw that, the low current, but it seems like it might be ok:

Say the Vbat was 4.2V (a worst case in this case) and Vf of the emitter is, say 3V, so that’s a 1.2V difference.

The Rds(on) is 7.5ohms, so I = 1.2/7.5 = .16 amps or 160 mA.

If Vbat was 4V, then I would be 1/7.5 =~133 mA

I was just thinking that if this was viable, it’d at least let me test if the driver was working while I wait for the “real” FET…

97

Sounds legit. Who cares if it burns anyway, right? It’s just a low current FET out of the parts box…

98

How does one connect a Batt+ to this driver? I see a pad, no space for spring, no space for button, little space for solder blob…

99

Maybe use a separate board?

100

Thanks. That may be an option. Any other choices?

By chance, the links are dead, does anyone still have these files?

101

What files must be included in that archives. Project files or firmware maybe? If you need gerbers for pcb there is possible to be downloaded from shared OSHpark page.

102

Importing gerbers to CAD software to modify them is problematic. As of now I don’t think I could do it but I would be glad to be able to play a bit with it.