Only simple resistor bleeder between driver + and gnd is required. I think the point is to have these fet switches for those who (will) sell new lights together with fet switch, in that case seller modifies driver and end user doesn't have to do any kind of modifications.
Or:
Of course, and one is waiting for the assembly:
Driver: LD-B4-20 in 8-12A configuration
Leds: 6x Luxeon V (very floody), 6xLuxeon V2, 6x LUMINUS SST-20 4000K 95CRI, on mosX PCB (with MOSFET+NTC+connector).
Hi L4P! 
I now understand that bleeder mod on driver… Piece of cake.
I just visited JaredM thread and I will have to quote myself here again:
I think that it is not big deal for personal mods or if someone starts with flashlight sale from 0.
But it is big deal and problem for someone who already sold lets say 200 of lights on market and now he wants to offer special version of FET switch for that lights because that switch won’t work with “old lights” because previous versions of lights don’t have bleeder resistor modd on drivers.
I am in 200 + situation, and I am probably sure that I am not the only one… Because I can’t offer special super FET remote switch for sale without driver modification on older lights.
If there is a way without bleeder resistor modd on driver I would be interested. For now I am not interested because of mentioned “bleeder resistor modd on driver”.
Don’t give up from this. This is super and very good stuff. :+1:
But please if you have solution for my problem(I am sure that I am not the only one with this problem) please also offer version of FET switch without need for bleeder resistor mod on driver.
Bleeder or coin cell, I'm afraid there is no other option, maybe some drivers can leak a little bit of current by themselves, but that's too unreliable and temperature dependent.
You can offer old buyers driver modification, or just offer new sets for those who want it.
That is pretty much impossible in my case… Well theoretically it is possible… But then I would probably end up in mental institution hospital.
Because you can’t actually explain to people why some new(same) flashlights can have “special FET switch” while old same flashlight can’t.
People out of this forum are not even familiar what 18650 battery is and reverse polarity insert of such battery is only logical thing to them :laughing: :person_facepalming:
Try to explain to such person that if he wants to buy new FET remote switch from me that he must send me flashlight for bleeder resistor modification on the driver. And even if he understand what I am talking to him I will certainly not do it for free and that means buyers shipping plus return shipping plus my time to repack, solder, repack again and resend all that back to buyers address with post office?
Because of that I am skipping this for now… I can take few pcs for my(and my family) personal use but that’s it…
One day with the new series of hunting flashlight I will have that as an option from very start of production.
So please keep developing this FET switch.
This is something that is needed very much in a flashlight world (all kind of duty jobs like police officers, soldiers, safeguards, for hunters, for self-defense purpose, etc), actually we all need that :+1:
A lot of hunters are flush with cash and would totally not question a new generation of flashlight that comes with such a switch included. You get to sell an additional flashlight, they move their old light to backup weapon. Win win.
Yea it’s just a resistor but based on your post I can see you are more customer service and tech than marketing cause any other ‘brand’ would not hesitate one more inexpensive feature that lets them bump up the cost of a new product.
I kinda have my own brand but it is just one flashlight model. And when you have certain stock of that model(lets say 150 pcs) you got to sell that first because no one will want to buy old model over new model which has improved FET switch with bleeder resistor modd on driver… You could offer old model at lower price but then you messed up your earnings and not to mention couple thousand of $ for the new batch of lights, and not to mention you gotta sell almost half of them to be on positive zero, and rest half is your earnings…, a lot of time until you actually earn something…
But there is solution for persons with my issue and that is battery powered FET switch. I am pretty sure that L4P can make that one too
If you ask me remote FET capacitor switch with bleeder resistor mod on driver is ultimate hunting solution.
But remote FET battery powered switch also ain’t that bad. Main problem is battery of course and certain type of costumers: type 1. Costumers that are unable to replace it although they have clear instructions(they don’t wanna mess with that and then they call you, and then you talk, explain and loose your precious time because of stupid battery 
)., 2. In my case very few costumers who understands basics and would know how to replace it but they will be unable to get such battery(and of course they will call you and demand such battery and who knows will even I be capable to get it :question: , so again stupid battery problem… ).
So simple solution like FET capacitor switch with bleeder resistor mod on driver instantly bypasses all that unpleasant situations and you sleep more peacefully as a seller :+1:
If you want to use LED board with FET installed, LD-B4-20 variant is needed.
Bleeder is needed for lighted tailcap, you don't need signal wires option because you'll get those with LED board, if you don't have spring and LED wires in your modding box, then you'll need those too.
Current range - if you are building light with 6xsst-20, 8-12A is mostly used, but you can use any range (brightness vs runtime and temp. rise trade-off).
I finally got around to turning down the spacer so I could put the 6x SST20 board and ANNA optic into my C8F. I’m not sure if it is brighter than before but I do prefer this over the stock setup. The head gets warmer than before when held on high/turbo which makes me think that it is pushing more power than before even though it is the stock driver.
I’m going to order a -M (C11806) and a -W (C11807) optic for it. I suspect I’ll prefer the -W.
I don’t mind the 4000k and 95cri but it does seem like I prefer 5000k
Hrmm. I don’t remember seeing this before…
https://led4power.com/product/6x-luxeon-mz-5700k-90cri-led-lmz9-qw57-34-0mm-6xv-anna-mosx-mcpcb/
MZs are out of stock and discontinued, listing was on page for a long time.
I’m having lots of trouble reflowing Osram CULPMs to the aluminum 4x4040 boards on led4power.com. No matter how careful I am, I always end up with current leaking from + to the bottom of the PCB and the LEDs won’t light up.
I don’t think there is anything wrong with my technique, it’s worked well for over 50 LEDs so far. Leaded solder, not too much, plenty of flux, controlled heat, etc. I feel like there’s something about the board that doesn’t play nice with the LEDs, so could someone confirm that the LEDs and the board are indeed compatible?
CULPM1 is indeed 4040 footprint. Should work
I’m not sure what is going on with this particular board, but when I have shorts after reflow, I re-heat the board and one by one slide leds off sideways with fine tweezers and then slide them in postion again. That helps removing solder bridges.
Edit: if this is a MosX board it is more surprising even: none of the solder pads should be connected to the core, even not the thermal pads. In that case you may have a defective board where somewhere the +pads are connected to the core. Can you see any dents that could have caused that?
I’ve done that, no luck.
They aren’t, they are connected to the + pad. This whole undertaking has been an exercise in frustration, I have no idea why the LEDs don’t work. Looking at it through a magnifying glass I get the impression that the pads for the LEDs don’t align well with the LEDs themselves at all but I don’t have a short between the + and - pad so that’s probably not it either. The website says the boards can be used without the MOSFET but recommends shorting the footprint in that case, but that just creates a short between + and - so I’m not sure what’s up with that.
By now I’ve probably reflowed some of the LEDs 10 or 15 times. These aren’t even reliable anymore. I think I’ll just abandon the project.
Has anyone successfully used one of the 4x4040 mosX boards?
Im not sure if this helps but I guess I used on in my OL contest build in 2019.
Check the photos here:
I am not sure if I have more with details, but I will check my G. Photos!
EDIT:
Thanks! Yeah, I definitely was unable to get t anything to light up in that configuration.
I have one in use. I had to solder LED+ to the pad that the mosfet would be on, iirc.
Important note to customers:
there is a final extra 10% discount for everything in store (code L4P2021) and it's valid until 29.12.2021.
Currently all items in store are bought and sold over my first smaller company, which I will close on 31.12.2021., and switch my business to 2nd LTD company (which I've used for lager customers and some other work).
Because I cannot mix parts bought over 1st company with stock of 2nd company, everything you see in store except for Osram LEDs is available only until 29.12.2021.
This includes LD-x4 drivers too - so they'll have obsolete/end of life status. I will not make and sell them over my LTD company, maybe if some larger buyer still needs them, 100+pcs will be min. order, but this is also questionable and depends on chips availability.
That also means there will be a gap regarding drivers availability until new driver generation is ready (and that depends a lot on chips availability, which is terrible currently).
So After New Year things that will be available are new 3030,3535,4040 16 and 20mm DTP PCBs (refreshed design), Osram CSLNM1.TG, CSLPM1.TG and CULNM1.TG, and limited qty of Luminus SFT-40.
Over time I'll add some more items in stock.
Good news is that bare LEDs will be available too, and every item will have better, more aggressive price breaks for larger quantity.
Shipping to UK without 135GBP min. order should be available too.
Orders made until 29.12.2021 which contain driver may be shipped with some delay, because I don't have lot of parts for drivers left, so it will take some time (5-7 days) until parts arrive.
Thank you for your support and I wish you happy Holidays and better New Year!
Do you have any remaining 4xV MCPCBs?
I’d like to build a quad Luxeon MZ but see that the 4 emitter + MCPCB combination is out of stock.