Led4power.com : LD-4 CC linear drivers, ILC-0/1 illuminated tailcaps, optics, MOSX, copper DTP MCPCBs...

Neven,
I just received my order yesterday. Everything looks great. Sorry you had to shutdown again but I’m glad business is going well. The new boards you mention do those include the quads in 3030 and 4040?

3030 tripe and quad yes, 4040 3x/4x possibly (DTP Cu).

How about the Q8 boards Neven?

Cool! Thanks Neven!

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Installed the X6 Luxeon Quad! And LD-B4 12A driver- Beautiful!

One question, on highest mode the light flashes 4 times and steps down to quite a low mode after about 10 seconds, is this a mis-configured temp stepdown or something?

Thanks in advance!

Probably it's OTP (default is ~55-60C), you can modify/disable it following instructions from datasheet.

Neven, when your store will be open again, will there be new drivers available that were mentioned some time ago?

I can't precisely tell when since I'm still in process of opening LLC. What can I tell is that I can't "transfer" stuff (LEDs,PCBs etc.) I currently have to LLC, so that sucks, I will at the beginning only have new stuff (MCPCBs, Osram LEDs, LD-x4 drivers). I'm working on drivers (lack of time as usual).

led4power.com ……… not opening / working……… :weary:

Post #1315 :

Disabled it and it worked fine, so I wondered if the board needed better contact with the spacer.

Sanded the legs of the optic a tiny bit, to make sure they were not ‘bottoming out’ before pressing down on the mpcb. Cleaned and re-applied heat transfer compound.

With temp regulation on, light now works for 1min+ before it gets too hot and steps down, all good :+1:

LD-A4/B4 use external NTC sensor for temp. measurement, so driver contact with spacer is not important. Is seems that LED PCB did reach ~60C, which is not too surprising, but if flashlight itself was relatively cold that would mean bad thermal contact somewhere (LED PCB - spacer, or spacer - host, or both). So I would check if there is enough thermal paste, maybe you have aluminum burr/dust from drilling between spacer and host which prevents proper thermal contact etc.

I wonder if there is a way to leave the item descriptions online without the store. I had trouble getting a triple Luxeon MZ working on a MOSX PCB until I found in the Google cache I needed to bridge the MOSFET footprint.

Only way is to manually change stock qty of all items to 0.

As I learn about drivers sometimes there’s a thing that surprises me.
This happened with LD4 recently.
5mΩ resistance is quite low considering that you probably need to sense current somehow.
I wonder if you do this with a really low value resistor or use some other sensing technique or sidestep this in an entirely different way.
I know that the exact construction of LD4 is a trade secret and I don’t ask you to reveal any special sauce but if this actual thing is not something special it would be great to read it.

5mOhm driver resistance is accomplished by using 1mOhm sense resistor (nothing special about it), FET adds about 3-3.5mOhm, traces 0.5-1mOhm. LD-2/3/4 design comes from era when XM-L2 and XP-G2 were most popular LEDs, and they both have very high Vf, so driver with lower resistance allowed higher output on max. mode. But there is always trade-off, in this case lower resolution on low currents.

These days basically all good emitters have quite low Vf and there is no need for such low parasitic/internal resistance (that's why my next drivers will have 10mOhm sense resistor for 5Amp driver).

I see, thanks for the explanation. :slight_smile:

Neven, some time ago I installed one of yours 9A driver on a 14500 flashlight, powering 3x XP-G2 Leds.

It worked fine until some weeks ago, and I just wanted to perceive what may have happened.
What happens now is that it only works with 2 modes, like Moonlight and Turbo, no matter how many times I click, I can’t enter the programming mode.

Could it be some component that “burned” or got damaged, and that originated this inability to have more modes or enter the programming?

BTW, the host is a Jaxman E3 and I am using a forward clicky switch.

Thanks in advance!

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