Not arduino. LEDs. I want to learn

Hello all. Happy Holidays! I am making far red 730nm LED fixtures.
I have 12 three watt 2.2V 700mA LEDs.
600mA 30-60V 36W constant current LED drivers.
12 LED PCBs that can handle up to 700mA current.
When assembled the LEDs flash. I soldered wires to all LEDs thinking the PCB could not flow the rated current. The LEDs shine nice and bright now. Why? Everything on paper makes sense to me. It should work without the additional wires. I am just trying to learn why my fix worked. Thanks all.

Photos

59413BC9-420E-48F8-B387-E6BA3CC71E7A.png

18D325BB-8AE4-4822-B0DD-9651A4A48080.png

BFE6A5AE-B687-476A-A49B-EDC321E27B55.png

59413BC9-420E-48F8-B387-E6BA3CC71E7A.png

18D325BB-8AE4-4822-B0DD-9651A4A48080.png

BFE6A5AE-B687-476A-A49B-EDC321E27B55.png

A schematic is worth a thousand photos!

Paul

I know the rules. I just didn’t think it would be necessary. Not much to it.

The LEDs are wired in series. The PCB is series. Without jumper orange wires LEDs flicker. With jumpers steady glow.

vender:
The LEDs are wired in series. The PCB is series. Without jumper orange wires LEDs flicker. With jumpers steady glow.

Can't see any jumper on your schematic.

The PCB is your design? Does it have wide tracks with nearly all area covered with copper? Or there are only default narrow tracks? If they are narrow they may have too high resistance and the source cannot supply voltage high enough to compensate for the I.R losses. As it is running to its voltage limit the current varies and so the LEDs flicker. Adding jumpers decrease resistance and solves problem.

Thank you. The traces are 2.5 at the narrowest point. I tried to calculate how much current that can carry but I simply lack the knowledge.

Sorry. 2.5mm width

No these are not my design they are ordered from AliExpress. I have found in three spots the traces get very narrow and by simply putting a jumper in those three spots is all I need. I don’t know if you can see it in the photo.

No these are not my design they are ordered from AliExpress. I have found in three spots the traces get narrow and by simply putting a jumper in those three spots is all I need. I don’t know if you can see it in the photo.

vender:
No these are not my design they are ordered from AliExpress.

How about a link?

All the same parts, same assembly process. Each end product has different result.
still flash 5%
work with no rework 15%
Jumpers at narrow traces 50%
Jumpers at each diode 30%
So it does work and perfectly for 15%. I just wish I knew why. I did some research and I have found that caps need to be added on the main side of power supply. Idk. Very odd that doing the exact same thing with the exact same parts has different results. I forgot I have two units I can not stop them flashing at all. Thanks!

LEDs
US $31.77 30% Off | 100PCS 3W High Power LED 730nm 740NM Lamp IR Far Red LED Far Infrared LED 3W 720NM IR LED Diode Emitter Light For Project DIY

Plate PCB
US $4.23 20% Off | 10pcs 1W 3W 5W LED Aluminum Base Plate 76mm 245mm 300mm 500mm PCB Board DIY For 3 9 12 21 10 30 36W Watt High Power Light Beads

Power supply
US $10.45 5% Off | 3 Pieces Isolation 36W AC85-277V LED Driver 10-18x3W 600mA DC30-60V LEDPowerSupply Constant Current LED Bulb Lamp Free Shipping

Just an update on the mains input I replace the 10 pF capacitor with a 22 pF and that seem to fix the problem. I don’t know why I am just guessing when I do these things.

It also seems I may have had my heat to high when reflow soldering on my hot plate? From researching it seems to be a problem with these cheap drivers also. People are adding more caps to the mains input side. I am glad I have them randomly working.