[Canceled] Sofirn SP70 BLF Edition

Hi FlashPilot... here it is

https://sofirn.aliexpress.com/store/2933049

That’s just the store link

It still shows the OPR.

Had posted about that and deleted my post cause mixed up reflector types. Just in case anyone wonders what that was about.

OK, the home page shows a banner, out dated banner, but still a banner saying BLF-Sofirn SP70 which we know doesn't exist.

Really looking forward to this release

Thanks for the clarification. :+1:

I think this one might fit nicely for SBT90.2 ? what dha yee think?

Not really. You can run a 3v driver with a single 26650 and a spacer, but that’s not a lot of power and your wasting space.

You can run a buck driver and 2 batteries but I dont think there is a driver powerful enough to really push it hard.

So not a good design form for a high power 3v led.

Need some info on the SP70 driver, anyone know the input voltage range?

More specifically will it run the xhp70.2 from 4.2v or 12v?

EDIT: I found the answer to ^ this^ from Sofirn in my email: Input voltage: 5.6V-8.4V

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Still wondering what type of driver it is? FET/DD w/zener diode?

Ok, my pictures of the driver are better than Sofirn's:

This is a classic FET design. Using the top pic as a reference, the large part on the left is a FET, one we are familiar with in fact. The bottom right pin of the FET is the FET gate, and you can see connected to that the 2 standard resistors our designs use for the FET gate - one is a low value inline, the other is a high resistor value going to ground.

The 5 leg part on the right is an LDO, to bring down the voltage to ~4V to run the MCU. The 3 leg part on the bottom appears to be another FET for lower power, but it appears to be not used, not connected to the MCU - I'm not sure, would have to trace the circuit myself.

I've seen these kind of dual FET, one hi power - one low power, driver designs before. In fact the Haikelite HK04 is very similar:

This uses 2 high power FET's instead of 1, and the part labeled Q7 near the FET's is the low power FET channel.

Nice work Tom E. :+1:

It’s connected. Look at pin 7 next to the “F1” on the MCU.

The small FET top pin looks to be ground get power through R2. Maybe that’s how they limit output? It’s not very robust looking (R2) so it must only handle very low output levels.

Then the bottom right pin looks to be hot grounded from the vias. (Logical guess) We need a picture of the backside to confirm.

Texas_Ace built a twin FET driver for the Haikelite MT09R. The smaller FET used a whole bank of resistors to limit output. It controlled thousands of lumens. This Sofirn small FET channel looks to control a couple lumen hundred at most.

You are right about the pin 7 connection. All N channel FET's I know of need ground for input. I also agree about the R2 limiter - can't handle much power.

That HK04 driver is for a quad XHP50.2 V2 light so the amps are pretty high, higher than the MT09R and compatibles, though at 1/2 the voltage.

Hello guys.
The little FET (Q2) you are talking about is “Moonlight FET.”
The right pin is connected to ground, the left pin is connected to the MCU, the upper pin is connected through a resistor (R2) to the black wire (negative) of the LED. Resistor R2 limits the brightness of the moonlight mode.

I did not understand the question.
If you mean limiting the maximum power, no, they limit the maximum power to a fixed upper level PWM.

RD: Interesting - moonlight levels are typically a problem, so they probably only use this output channel for very low output levels.

How do you know all this? Is this basic EE design stuff, or do you know this driver specifically? In my case, I'm a SW engineer knowing enough of EE design to get myself in trouble... I've actually learned more here on BLF and working with flashlight drivers than on the job. In the last few years, I haven't tinkered much at the low levels of MCU's. Our dept. is big into PIC controllers but I'm not involved much at all in them.

I'm doing heavy C# work in the panel Win PC's we use on our devices now.

All that I know about designs and driver circuits, I learned in a short time spent here on the BLF. I have some knowledge in electronics, so it’s interesting for me to study various drivers.
As for the driver SP70. Sofirn began to use a similar driver design (PIC - Main FET - Moonlight FET) in the C8F 21700 flashlight. A similar driver is also available in SP33v3. I don’t know why they used Moonlight FET, maybe they had difficulties, or maybe they went the simple way.
By the way, the moonlight channel does not use PWM, It works as ON / OFF.

I've built up FET only drivers before, using NarsilM, for high powered lights - 6V LED's with 20K to 40K lumens, and at the low levels for ramping, it gets very jumpy, erratic. I didn't really care too much - the lights were really for the wow effect on high output. For a production light though, I'm sure you have to have some low lumen output support.

Ah, thanks. This makes more sense now that I look at it. The bottom right had to use vias because it was surrounded by signal traces and cut off the ground plane all around it. I edited my original post to not confuse people.

I agree. It looks like this method uses this driver.
The moonlight channel is included in the full range of ramping and is used to support low lumen output.
For the experiment, I took the C8F 21700. At a low ramp level, the duty cycle of the main FET = 1.86. I unsoldered the moonlight resistor and got a very low output of 0.3-0.4 lumens at a low ramp level. If set the duty cycle of the main FET 2.0-2.1, it is possible to achieve an increase of 1-2 lumens without using the moonlight channel, but it is very difficult to set a low level, the brightness changes too fast.
We also have another problem, drivers may need to be calibrated, since different batches of electronic components can give different results.
And you are right. For mass production, it is easier and more stable to use the option with a separate moonlight channel to support low lumen output.

Thanks for the answer and photos. Refreshed my memory as I now recall learning about the LDO drivers a few years back.

I could also use this type of driver in smaller form (17-20mm) and for tail clicky. I’m pretty sure Adventure Sport and MTN both sell a zener modded 17mm FET/DD, anyone know who makes one with the LDO instead?

Or a 17-20mm constant current driver with LDO and high amp output?