[Prototype/Preorder] Emisar D1/D1S white flat Linear CC FET driver


any recommondation what to change?

I can sell a few prototypes
Price as usual is 12€
Anduril or NarsilM as firmware

shipping is 1.4$ from here untracked
5$ tracked with 25€ loss insurance

after the first ptototype failed due to PCB bug I can now finally announce I it for white flats running

first Prototype 20mm small LDO and MCU did not work out

2. Prototype of 22mm with D1S specifications works

ignore the flux residue I had to change some values to tune it

still a few things to be addressed, like The not tented Viases next to the LED- Pad that are ground, they are there to get heat from MOSFET note spread but should be below mask

Interest list

1. scr79423 maybe a rev 1.0 Prototype board
2. 808Hi interested in rev 1.0 Prototype board

Very cool, Lexel. Is the current locked in at a certain amount (or controlled via firmware or a resistor)? When dimming the linear-controlled FET, is there any PWM? How low can it go?

I really enjoy my D1S with a Flat White and 5A linear driver… but I cheated and used 5x CN5710’s. :smiling_imp:

I can go down to about 20mA when 4A Turbo is adjusted over the current set resistors

it is pure CC fet so no PWM at all
if I would drop the indicator LED output it would be even possible to get an AMC for Moonlight, but on a thrower moonlight is not really needed anyway

It is possible to build a firmware with different max currents but as people tend to play with it you can easily kill a white flat

Interested in DS1 prototype

I have still to wait for a D1S that is coming now from China
also make final board design order within the next days combining with other stuff

the final thermal tests is something I can not do on my PCB vise like with regular DD+7135 drivers
all the heat is generated in one spot within the MOSFET and due to the electrical path they can have no ground fin like AMCs

unfortunately I likely have to chop this flashlight partially open so this will also get into the prototyping costs,
because I have to do proper use of my infrared thermometer getting to max. current that the driver can sustain in the light without getting to hot
and I simply want so see how effective the solder filled thermal viases are, or if I may have to add some copper sheet on the MOSFET somehow
I would not trust contriving in a thermal probe from the LED side somehow

The goal is to get to 7 or even 8A without getting higher than 120°C on the MOSFETs hottest spot while the Lights head is 60°C hot
and also this has to take into account having a battery loaded to get proper thermal contact and voltage sag of the inserted cell to be as close to real working conditions

.

The last thing I want is selling 8A SST 40 drivers that fail after constant use because the board gets too hot
from the L4P driver we know the 4A of 1mm² white flat are no problem, but regular fibre glass PCBs have their limitations
Also the first prototypes that I have here are made on my regular 1Oz orders, while final ones will be 2 Oz copper

Nice work Lexel. Donated a little bit on your gofundme page for this campaign. Question. Would this be also a good driver option for 3V quad e21as with even lower vf? D4 quad e21a maybe?

Yes, but even worse.

With quad E21As/Nichia 219Cs, a buck driver would actually better serve you.

Would be ideal. But where does one get 1S buck driver with e switch firmware?
Can’t buid. I’m currently using AMC7135 drivers to drive a couple of my quad e21a lights and I’m ok with them despite the losses. I’m figuring Lexel’s white flat drivers might be a step up in efficiency. Or am I wrong?

In any case, I do need this driver for a white flat d1s. So I’m definitely interested.

In for one

I had started in january on a 12 maybe 14A 1S buck driver but yes not really got any time to look further into it

Nice. :slight_smile:

Any updates on this driver?