LEDgardener

It looks like genuine LM561c's.

HLG QB 288


My Chinese PCB


Visual test pass, but how do I test for the bin?

I'm seriously considering buying a large enough quantity to have them branded and offer a cheaper alternative to HLG. If the only way to test for bin is to send a board to a lab for testing I'll do it. Can anyone suggest a good one?

Or if anyone here has the capabilities to test it, I'll send it to you and you can keep it for testing.

Hmm. I've heard of a lot of LM561Y chips floating around China that are being sold as LM561C. They look identical, as you can see: https://e-neon.ru/catalog_files/pdf2/lm ... f?escape=1

They're inferior chips with the exact same build and even share the A1 and AZ voltage bins that the LM561C uses, though the lumen bin is restricted to S4. You'd really only know by testing with a sphere or maybe a side-by-side test vs. a quantum board of the same color temperature.

I learned my lesson, with Chinese suppliers...

I'm not rich much, that I can buy cheap...

They are good for a small box, clones and mother plants...
In most cases, chips looking original, but they produce more heat and like LEDG said they are not the same as on original HLG QBs.

As I've posted elsewhere, I got my order from Mufue with a 3 week delay, only to discover LM561B+ instead of LM561C (failed already on visual inspection.) Generously assuming, of course, they're even that and not Epistar chips.

Had they passed visual inspection I would have taken apart two strips to inspect diodes in detail. See here (starting at minute 8): https://www.youtube.com/watch?v=tazN0W3fi0M

majorana wrote: ↑

Wed Apr 25, 2018 12:00 pm

As I've posted elsewhere, I got my order from Mufue with a 3 week delay, only to discover LM561B+ instead of LM561C (failed already on visual inspection.) Generously assuming, of course, they're even that and not Epistar chips.

Had they passed visual inspection I would have taken apart two strips to inspect diodes in detail. See here (starting at minute 8): https://www.youtube.com/watch?v=tazN0W3fi0M

Nice find on that video

I'd be happy to learn of other methods to tell the different diodes apart, beside measuring lumens, of course.

I made sure to order a couple of extra strips so I can tear them apart for this detailed physical inspection.

we need to know which suppliers are cheaters. thanks for the work.
fortunately for me it seems, i decided to buy bridgelux vestas and f562b instead of any supposedly Lm561c from alibaba (meijiu, bava, hansion, mufue). mainly because of the high shipping fees (35$) compared to digikey (free)

LEDG wrote: ↑

Wed Apr 25, 2018 6:01 am

Hmm. I've heard of a lot of LM561Y chips floating around China that are being sold as LM561C. They look identical, as you can see: https://e-neon.ru/catalog_files/pdf2/lm ... f?escape=1

They're inferior chips with the exact same build and even share the A1 and AZ voltage bins that the LM561C uses, though the lumen bin is restricted to S4. You'd really only know by testing with a sphere or maybe a side-by-side test vs. a quantum board of the same color temperature.

Doesn't it seem a little odd that the only datasheet for the LM561Y is on some russian website and not on samsung's website? Even if it's an outdated chip the datasheet should still be on their site. Just like there are 4 different datasheets for the LM561C, with revisions.

Unfortunately the LM561Y shares the same forward voltage as the LM561C so you can't just count the number of series and find out that way.

Here is a pic of the board.

I see you chose to go with Meijiu for the boards. I have bought and sold their boards before, and have feedback from a customer that that board was brighter than a Closet Case 140 from spectrum king when hung side by side. The CC 140 was $200 more expensive than what I sold him my kit at (around $120).

Despite that positive feedback, I was disappointed in that it was only 1.6mm thick. Their 240pc 36V board is the full 2mm and bigger size wise, and may be better at heat dissipation. when the customer switched the driver out to a Meanwell HLG, he reported a reduction in heat over the driver I sold him (meanwell LRS 100-48). Just sharing my experiences but yeah, it is a decent board imo.