Driver: F-8 v2 (17mm FET driver with 8 x 7135)

Flashlight Modding and DIY Parts
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New version V2: Added FET gate resistor.

For those interested in this driver, read this first: Mike C drivers and X85 firmware.
Firmware available in second post of above link.

This is a 17mm board that has 8 x AMC8135s and a FET. Any number of the AMC7135s can be turned on for constant current steps of 350/380mA, and one of them is used for PWM between the constant current steps, and a FET full on for boost. For this setup all pins, including the reset pin, are used. However, the solder pads on the front side allow different setups so that the FET can be PWM:ed, and also the reset pin can be avoided by grouping more 7135s on a single pin and using PB3 for the FET. By default the group of 4 x 7135s and the FET are not attached to any pin, so the soldering the solder pads is needed regardless.

Details:
17mm board (made slightly bigger so it can be filed down for a snug fit).
ATtiny85 (requires legs to be bent as in photo below).
E-switch, off time cap and voltage divider on the same pin.
Zener ready with dedicated zener footprint.
Selection of position for input capacitor, either before protection diode/zener resisitor (CIA) or after (CIB).

Notes:
No spring. Two 1.2mm vias are used to solder stiff copper wire over the MCU (photos below). 1.2mm because stiff wire I had laying around just fits in a 1.2mm via.
Must cut tab off the AMC7135s or they won’t fit.
0603 Resistors and capacitors, resistors not “BLF standard” values (info below).
SOT323 diodes (protection diode footprint modified to accommodate zener resistor better for zener drivers).

Components:
Here is a list of the components I have used. These item numbers work using search on both http://uk.farnell.com/ and http://www.newark.com/. Those using other sources should be able to figure out what is needed. These might not be the best components but they work for me. I’ll take suggestions for better components if someone has any. Note that I haven’t yet tested the Vishay SIRA00DP FET but I have a few on the way.

For both zener and non zener drivers:
MCU: ATTINY85V-10SU, item# 1455166
FET: NXP PSMN3R0-30YLD, item# 2400981
R1: 0603, 1M2, item# 2141572
R2: 0603, 300K, item# 9330992
CI: 0603, 10uF, item# 2211164
CO: 0603, 1uF, item# 2346895
RG: 0603, Gate resistor of choice (I haven’t used one yet).

Non zener:
DI: SOD323, item# 1459171

Zener:
RZ: 0603, 200 ohm, item# 2447292
ZD: SOD323F, 4.3V, 500mW, item# 2069514

Photos:
Some details differ, different versions.

Bottom of driver and ATtiny85 with bent legs. Also note the AMC7135s have cut off ground tabs.

Top of driver with two pieces of stiff copper wire soldered into the vias. Also note the AMC7135s have cut off ground tabs.

Soldered together the two pieces of copper wire. Note that I put solder paste on all of the solder pads during hot air soldering to make connecting them easier.

LED+ soldered to copper wire. Solder blob filed down slightly.

Pieces of wire are bent in and then cut off so the driver fits inside the host or pill.

I used an earlier version of this driver in this light, and it has been very reliable: Mod: My take on the convoy S series with side switch mod.

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This would be interesting in a high power light… full regulation for l/m/h and then well 8+FET for turbo! Would be nice in a D01 or maybe a Convoy 26650 e-switeh light.

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Thanks for making this available Mike. I think its a smart design; I like how it seemingly utilizes ALL of the space on the 17mm board, if not for components then for grounding and vias. Nice scheme for the + connection!

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Thanks. I’ve used this F-8 driver in this light, but it’s one of the earlier versions of the board: Mod: My take on the convoy S series with side switch mod.. Add link to OP.

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I like it. Nice.

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Updated OP with component list.

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New version V2 with FET gate resistor, OP updated. Also, firmware is now available. Details and download in second post here: Mike C drivers and X85 firmware.

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Mike - did you try those SIRA00DP's? I just ordered two, then thought of searching BLF :FACEPALM:

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Sorry for late reply, I’ve been on vacation for just over two months.

I’ll have to check which ones I’ve tried, but as I don’t use PWM on the FETs at all my experiences might be irrelevant. Anyhow, as this is late you might already have tried yours.

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Hi Mike good morning. Would you be able to build me one that can use 4x18650 in series for an xhp 35 LED emitter? How much would it cost in total for the shipping to the Philippines.

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The problem with 4 cells in series is that the high voltage might fry the regulators. For single cell drivers I use the 7135 for non FET regulation which is rated at 5 volts I think, and for multi cells I use the A705 which is rated for 12 volts. 4 cells will reach over 16 volts when freshly charged, I haven’t actually tested to see if the A705s can handle 16 volts. I can sacrifice one and give it a go.

The actual driver in this thread is obsolete though, these are what I’m working on now: Mike C drivers: v8 series, ATtiny1634 based.

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I bought the Solarforce Gladiator and I want to use four 18650 for longer runtimes.

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AMCs are rated absolute max 6V
They work with 8.4V on the output but sometimes the have a faint leK current
as the Vdd is still 5V from the MCU thats in most cases OK, but in some 20000 lumens light the drop from Turbo to a lower mode can fry em, because a vltage spike is generated