2022-04-30: Quite a while back, I did a teardown of a Meanwell IRM-01-05 power supply. Recently, these power supplies have become a little hard to get a hold of through official channels. So I began searching for alternatives. I stumbled across the Hi-Link HLK-PM03 (yes, its 3.3VDC instead of 5V), but noticed that the datasheet (PDF, 13 Pages, 880KB) says you need additional components on the input side and a large output capacitor...

I began wondering why... There's not much space for additional components in my application. The fuse and an inductor/capacitor and output capacitor are in the IRM-01-05. What was different about this one? Was it because there wasn't any room inside due to the higher wattage output? So of course, I had to order one and open it...

Top of Power Supply

bottom of package

Potting after popping the back cover off. The 3 holes are from plastic prongs sticking up from the back cover, probably to keep the circuit board from floating out of the potting.

After removing the bottom cover and some soft sealant (much better potted than the meanwell IRM), we can now see the reason for the change in the datasheet - the input power supply pins go directly to the rectifier (marked MB10F)

R3 is marked 304

D2 is marked A7

C1 is Chong X EHT 6.8uF 400V -40°C to 105° Capacitor

Top down view

Lets check the bottom of the board..

D1 is also marked A7

U1 is marked SPT SP6623F 21CT01

Resistors should be readable from the image for the most part.

HLK-3M Rev: 1.1 2020/2/25

U3 marked 431

D3 is marked SK 34 833

after removal of the transformer and the capacitor, we can now see the optoisolator (U2) labeled EL 357N C024

 

No markings at all on the transformer itself.

Side View

CY1 is labeled JNC JN102M

 

C7 is marked 470 uF 6.3V PXJ78

C8 is marked Chong VEHT Low ESR -40°C to +105°C 330uF 10V

 

And that about wraps up the dissection. There's probably a lot more info that could be added to this, but this was enough to satisfy my curiosity. This little power supply definitely needs the extra input side components for safe operation- they're simply not inside the unit as I was hoping, but the output capacitor still has me puzzled... Maybe if I still remain curious, I'll do some electrical testing, but for now, I've run out of time. Hope you enjoyed the information.