Bought some cheap led desk lights from IKEA, the "Jansjö" model. These are 3W led lights on a flexible arm, they seem to be quite popular in the DIY machining community as small work lights.
These things are only about €10 each. Of course made in China, so I wanted to check the power supply to see if it was one of those Shenzen Specials or if it was actually properly made. Note that the power switch on these lights switches the secondary side, so the power supply is always on when it's plugged in.
I pretty much expected a shitty capacitive dropper type power supply, but it's actually a proper switch-mode unit.
The power supply in question. Made by Kwong Ming Electrical MFY. Wide input range, so this is probably the power supply used everywhere.
It's ultrasonically welded shut, but it can be opened using a bench vice and some percussive persuasion.
Notice quite a large lip around the edge and 3 extra pins to hold the case together. Generous amounts of goop hold the components in place. The output power connector is held in place by the case, it doesn't rely on the PCB for mechanical strength.
Power leads are crimped on the pins, and the pins are a one piece U shaped molding. These aren't going to break off.
The chip is a PHY368DA. Can't find much on it. All the capacitors are "HD" brand. Nothing special. Note that this power supply barely gets warm, I don't expect any issues here.
Blast from the past, old school DIN 41529 connector.
The money shot. The isolation gap is 7mm, and there's a routed slot with plastic protruding. Quite an elaborate design for such a cheap product. This thing just proves you can actually make a decent power supply for almost nothing.
I measured 6.90V with the led connected. An interesting thing is that it doesn't output anything when there's no load connected. Just a tiny peak once per second, I guess to check if there is actually anything connected. This obviously reduces the standby power consumption a lot.
So, thumbs up. IKEA proves you can make a dirt cheap LED desk light and still provide a reasonable power supply.