I added input capacitance to a bunch of Qihan units I had lying around after reading a report of high mains output ripple by some fellow from Mordor or thereabouts, :-)) too. This is a QH-40W-LP with 3 × 15µF (cheap) capacitors:
Let me also share a photo of a 20W “Dark Energy” driver I bought from eBay, which came with good input capacitance:
The above unit had no components on the underside. And I couldn't find sense resistors above either, my guess is they are under the transformer.
It is good 20w led driver. I used it 4-5 years ago in lamps for plants. 25P model. But 600mA disappeared from sale. After that I moved to 20w led driver from Qihan =>22P
About ripple.
There is 2 types of led drivers from Qihan. 1st have no ripple (pulse) in out. This type only 5-20W
2nd is led drivers with good power factor (~0.97). There is only one way do do it not ripple - add capacitors in out.
No actually I don’t prefer violet spectrum for my needs as I’ve tried a few. I’m only looking for some to replace my current household lightbulbs for nighttime use. I prefer 2700K with a negative duv or below the Black Body Locus tint. I’ve tested many bulbs in the past and only the GE Reveal offers this combo but they keep burning out. Their reliability is the worst I’ve ever seen.
Wow that is some massive output capacitance! Am I seeing the driver came with 8.8mF (4 × 2.2mF), and you added 3 × 6.8mF = 20.4mF to fix the ripple? LoL!
What's wrong with adding high voltage input capacitors, the power factor goes down?
What he means by Duv is “Delta uv”, or the distance the CIE coordinates are from the Black Body Locus. You likely have never been asked that before, but on BLF it’s a huge deal to many users. Above the BBL is a greenish tint, that disgusts some people. And below the BBL is a reddish “Rosy” tint.
For me, a “rosy” Duv isn’t any better or worse than a “greenish” Duv. But some people need rosy.
This is about as green as the sun. But from other threads I know some members consider that unbearably green.
Heck, another member mentioned about a month ago they were trying to get the BBL standard lowered because they thought they had research supporting their claim the BBL itself was greenish. But that research seemed to be using “Fake White” RGB lighting.
I hardly doubt it is a galvanic isolated driver (propably some kind of flyback topology) so in this circuit this inductive component works more like coil/inductor not transformer.
No, I can not wait! I just send this lamp today. World must know this thing (190g weight)
2700/3200/5000/5600/2700+3200/5000+5600/2700+5000/2700+5600
/3200+5000/3200+5600/2700+3200+5000/2700+3200+5600
/5000+5600+2700/5000+5600+3200/2700+3200+5000+5600k SunLike10xss
It can be my last lamp. I am going to escape from the MORDOR. I just get passports.
I saw on post #107, Adam, your PCB layout was marked “CCCP”. At least in the USA, and especially the generations older than me, that can trigger political feelings. I wouldn’t recommend it for the next batch of PCBs. Sorry.
But on a happier note, I was wondering where you were escaping to? I assume it’s a vacation destination?