Hello there, ingles is not my main language so apologies in advance.

Anyway, I was just fixing a regular old led bulb, you all know the gist, 1 led burned, jumper it and plug when I noticed that there was no rectifier ic on the pcb, there was only one smd that seem to serve both as rectifier and driver in a single package, found that curious so I tried searching for that little thing's datasheet on internet with no results at all, tried all the pages listed on the first post in this forum as well.

All I found about it was the pcb UL certificate with a manufacturer that doesn't exist (DEXUNDA ELECTRONIC TECHNOLOGY CO LTD), the model I have btw is the DXD-AL1, on the pictures attached is the ic and a birdview of the pcb, below it there's nothing, just metal for heat dissipation, no hidden smd.

The manufacturer of the ic driver seems to be JW, no idea what it stands for and I don't have the tools to reverse engineer it, if anyone can help finding the datasheet, thanks.

Forgot to add, it have 7 pins, strange distribution as well.

 

Welcome to AAC.

Clearly the IC has a built-in rectifier. Note the two pins closest to the mains have extra separation from the rest.

I would suggest contacting Big Clive, who has a special interest in these things and high have some insight. You can become a patron of his on Patreon for a couple of dollars and it allows you to message him—and he does answer there.

 

There are literally dozens of Chinese semiconductor companies which are mostly unknown in the West, which specialize in ultra high volume and ultra low cost, niche applications.

It wouldn’t surprise me a bit that this IC integrates the rectification function.

 

I would suggest contacting Big Clive

Didn't occur to me, been subscribed to him for years.

literally dozens of Chinese semiconductor companies

Gonna have to try and find someone inside the wall I guess. Or maybe a vpn + chinese google might work, gonna try.

 

No rectifier needed if you do it this wah...

 

No rectifier needed if you do it this wah...

View attachment 293405

Yes, but you only get half the light.

 

but you only get half the light.

Not if you size the capacitor so that the average value of the half-wave current through each row of LEDs is the rated value.

 

No rectifier needed if you do it this wah...

View attachment 293405

The downside of this design is the unstable VAC makes it susceptible to heat and they would consume pretty much their max current, not very economic on that side, the good news is that with a simple diode and a parallel resistor to said diode right before R1 would trim certain percentage of the current to whatever value you set the resistor (maybe 10k or less) and would allow the use of the other half of the wave, the only thing to keep an eye is the power needed for the resistor (maybe 2W is more than enough for any).

 

I have had two of these things in my house operating continuously for 17 years and so far there is plenty of light and yes, the LEDs are running a less than their rated current. The whole reason I made these is because I became very weary of replacing florescent night lights every so many month, hence the low current. Nothing gets hot.

 

I have had two of these things in my house operating continuously for 17 years and so far there is plenty of light and yes, the LEDs are running a less than their rated current. The whole reason I made these is because I became very weary of replacing florescent night lights every so many month, hence the low current. Nothing gets hot.

Where I live AC goes wild, I'll try it anyway, couldn't find out anything about that company and already have all the pieces rolling around my desk, couldn't get the leds out thu...