In search for >3W 3-4V COBs

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L4M4
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In search for >3W 3-4V COBs

Hi!

I am currently working on my car which is standing in an underground car park.
I have this thing, which I modded with a 1Ah LiIon and charging circuit.

I would love to have something like that with more power – 5-10W
but I can only find 3W modules

Boards for 5630s for 3-4V, so driveable with a LiIon with resistor, would be even better (I have over 2000 bare 5630s laying around).

DoubleA
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Greater than 3W they make em with higher voltage. Smile

May I ask why you need 3-4V itself?
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Update:
Why not use more than 1 in parallel?

and on the first day he said "Let there be light"...

L4M4
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more than 1S is harder to charge because you need a charging-electronic.
With 1S I only need one of those TP4056 boards from which I have 25 or so laying around.

I am building a 20W floodlight that is been driven by 6 18650s and a CC Boost Converter, but that is a big light.
I would like to build something like those pen-lights, but in bright

DoubleA
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I meant why not use more than one 4V COB in parallel wiring. It would have the same effect as a higher wattage COB.

Example – 4× 3W COB in parallel= 12W but needs only 3-4V

and on the first day he said "Let there be light"...

L4M4
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that’s boring Big Smile

I ordered one of these COBs linked in first post – but I think I already had this thing and it wasn’t good enough for me – light color and CRI are not unimportant, even for a worklight.

DoubleA
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Generic Chinese COBs cannot give good you CRI. How are you going to solve the thermal problem when using a 10W pen light?
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Would you be kind enough to elaborate your requirements, because so far I don’t have a clue to what you really want. Do you want a 10W COB in the same size of the one you linked? With high CRI and tint? Your’e ok with using multiple 5630s in parallel but not COBs?

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Wouldn’t it be easier to use a Cree or Nichia?

and on the first day he said "Let there be light"...

L4M4
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I want a big COB (3×10cm or so) that doesn’t hurt my eyes because of Lm/cm² ratio if I accidentally look into it – that’s why a HP LED isn’t suitable for that.
That happens pretty often with one of those COB Pens.

Cheap chinese LEDs can give you a CRI over 80 – but you have to test those things out, which I do a lot.

But whatever, I think that I will just use multiple 3V 3W COBs for that

DoubleA
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You know you can always diffuse the light to make it more tolerable for the eyes.

The CRI factor of no-name LEDs are always hit’n‘miss, there is no guarantee what you will receive, besides anything below 90 is not considered good CRI which why people opt for Nichias.

and on the first day he said "Let there be light"...

L4M4
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but 80 is better than the <60 cheap COBs often produce Big Smile

I already have these 3W COPBs in CW and WW somewhere, but I can’t find them :/
If I remember correctly, they produced an ok light if used together.
so 4 or even 6 of them with some truLED in front of them, plus a 3-4× 18650 pack could be a nice and small floodlight.

Edit:
Found them Smile
I remembered correct, together they produce an OK neutral white light.

DoubleA
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Sure, but be wary that those generic COBs CWs don’t give the same CRI as their WW does.
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and yes you can combine CW with WW which is a makeshift way to achieve to achieve that neutral whitish tint.
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oh, and if I remember correctly some sellers on Ali can make you high wattage COB at lower voltage if you make bulk order.

and on the first day he said "Let there be light"...

Jerommel
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Certain cheap 5050 (XM-L(2)) boards have the perfect traces for a bunch of 5630 LEDs
These for example: https://www.fasttech.com/p/2116303

Just sand off the masking and reflow 6 (3 Watt) or 8 (4 Watt) of them on there.
Middle trace becomes the – and you’ll have to connect the outer traces to +

..waiting for parts..

Still looking for 5” parabolic reflector (for recoil light)

vwpieces
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Now that’s pretty Neat Jerommel.

L4M4
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Thanks a lot for that input!
I have seen your mod on another thread but didn’t notice where you got these boards from.
I just checked my stock and I found a board that has the same layout, so I will make a test-board.

Jerommel
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L4M4 wrote:
Thanks a lot for that input!
I have seen your mod on another thread but didn’t notice where you got these boards from.
Yeah, the mod from hell, as it turned out…
I finally put in a 7 mode Nanjg driver from Simon in it, but the LVP doesn’t seem to work, and the charging PCB is not working properly either.. (takes about 3 days to charge a Panny… Facepalm )

But i have used both 20mm 5050 and 3535 boards for this ‘trick’, but the 5050 boards are easier to use for this.
I found Fasttech sells these boards, so i bought 20 of them. (I have a bunch of high CRI 5630s)
They’re cheap boards, but good enough.
It’s only 4 Watts maximum, spread over 8 little thermal slugs, and when you run them at half power there’s very little heat to dissipate.

Quote:

I just checked my stock and I found a board that has the same layout, so I will make a test-board.

The difficulty is that the LEDs may float around when reflowing, so it is advised to use something not too hot on which you can lay down the LED board (a skillet perhaps) so you can position the LEDs before cooling down.
Some air bubbles may form under the LEDs while heating, so you may have to push them down (with a tooth pick or something).
For the rest, remove the flux (some of which will end up on top of the LEDs) when the board is still warm, with a cotton swab.

..waiting for parts..

Still looking for 5” parabolic reflector (for recoil light)

L4M4
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Quick & Dirty just for testing purposes.
works great and is a lot brighter than I expected.
I used 5500K and 4000K 5630s from GREE which gives a really nice mix.
And as you can see, it is kinda hard to alight them Big Smile
I use a croco-clip to hold the board and one of those cheap reflow-soldering machines to heat it from the bottom.
I first put solder onto the star, then a bit of flux and then the LEDs.
The flux makes it really hard to get them aligned…

Also I ordered 30 of these Boards from FT… for that price you can’t really go wrong.

Jerommel
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Yeah, they float around a lot when reflowing…
That’s because we have no mask paint on it..
I use the same method: tinning the PCB first, add flux, put the LEDs on and heat.

I was also pleasantly surprised by the brightness of my Osram Duris E5 LEDs.
Even though they’re CRI95, they’re definitely bright, and the Vf is low too.

..waiting for parts..

Still looking for 5” parabolic reflector (for recoil light)