As always, thank you for your fast delivery and good packaging.
But a word of caution for everyone buying a luxeon MZ: This LED does not like solvents / cleaning.
I managed to turn mine into a beautiful blue by trying to clean the flux from soldering: https://i.imgur.com/rszOsls.jpg
Also, are there tips and tricks how to solder the MosDTP + LD-4B driver in a host with an integrated shelf like the Convoy M1?
I had huge problems soldering the MCPCB inside the head and even when I managed to solder everything, the solderjoints at + and - were to big and were shorting to the reflector.
My approach was a small piece of wire which lifted the MCPCB enough so it was possible to limit heat transfer to the head.
Would another aproach like soldering the MCPCB first, inserting it and then soldering everything to the driver be a better idea?
What did you use for removing the flux?
It should withstand alcohol.
As for soldering very thermally conductive LED boards, you just need a powerful soldering iron, which can heat up a small area really fast.
That means a pointed solder tip is not what you want.
A chisel bit is much better.
When it’s really difficult i get my 100 Watt iron with a big chisel bit out.
Then the solder pads of the LED board have no other choice but to get hot.
First tin both parts you want to solder, of course.
Add some flux grease too.
Did that. Tinned the pad and then added extra flux.
But back to my last question: Which one would you suggest:
a) Solder wires to driver; insert into head; cut to length, strip and tin; add thermal paste; insert MCPCB into head with a spacer; solder wires to MCPCB
b) Solder wires to MCPCB; add thermal paste; insert into head; cut to length, strip and tin; solder wires to driver, insert driver and wire-slack into the head and fix
I would suggest a).
It’s often much more difficult to solder wires coming from the pill or head onto the driver, especially when you want to keep the wires short.
I think it would help to turn up the heat.
Just put it on max for the occasion.
That way the tip has a bunch of extra heat stored to heat up the LED board fast locally.
Your choice of bit is probably even better than a chisel bit.
If you pre-tinned the MCPCB +/- pad and wire (preferably with leaded solder so everything is easier) your solder blob that you pre-tinned should melt quickly with the chisel tip and iron turned up high (I think I do around 410-420c for this purpose).
Since the tip is so hot it will turn black, you want to clean it with a brass tip cleaner right before you go at it so it’s nice and shiny.
Your trick with using something to break the tight bond between shelf and MCPCB is good too if you can do it. I will sometimes prop up one side with a tweezer or lay it uneven on the shelf for a second but it’s not necessary.
Yes it was pre-tinned on both sides and I was using classic 60/40 solder. The temperature was probably the problem as I was using my standard 340°C soldering temperature…
Well, I’ll see on the next try as soon as I get another LED.
I would recommend b) for mosX/mosDTP boards, people who says a) - it's like trying to solder solid piece of metal with these boards, and you risk LED damage from too high temp.
I have never seen a board worse than Noctigon quads positive therminal to solder to
But still with 330 degree celsius and a proper solid tip and flux its no problem
Mostly if people say hard to solder they lack simply proper quality solder gear
The linked Hakko tip is ideal for soldering MCPCBs any tip can do as long as its thick and short
There is absolutely no risk cooking the LED while soldering leads to it as you never reach 240 degree temperature on the whole board even if you lift it
Heating the whole head to about 100 degree helps a lot soldering build in MCPCBs
If the MCPCB is heatsinked well it will suck the heat from the soldering iron.
You would need to set it to like 400+ degrees to even start melting solder.
The best option is to have the wires already soldered to the MCPCB, or at least not add thermal paste and tighten the MCPCB down until the wires are on.
Use that big hot iron with chisel tip but also: keep the tip clean. An oxidised tip can ruin the heat transfer very effectively while a freshly cleaned tip does the job effortlessly.
Just to keep you updated, I put the Luxeon MZ on MOSLED 4040 board in a Convoy M1 with an A6 Fet driver.
The beam is smooth with the OP reflector, and it does produce some nice lemons. It’s the first time I’ve seen such a cool tint with good CRI. It’s disturbing, I don’t know if I like it yet
Anyway, it’s a nice hand warmer for the winter :-p
The LD-4B driver is now set to 4.5A in my C8, along with an Osrma White Flat 1mm² and does a nice 160kCd
Note: if you want to order some of compatible pcbs with LEDs soldered for use with driver other than LD-B4, please add bare LEDs in cart together with PCB and leave a note about soldering.
on the LD-x4 drivers what happens if you set the current higher than what the cell or LED will support? Does it just act like a normal FET? If so, is there some extra resistance somewhere making this a bad idea?
It behaves like DD driver on that mode (so called dropout mode of linear power supply). Nothing bad will happen, this is normal condition when battery is more or less empty and (LED Vf + parasitic voltage drops) is higher than battery voltage.
