USB Power supply test web site - interesting content

[Fraser]

I stumbled upon a web site that contains many tests and teardowns of USB power supplies.

https://lygte-info.dk/info/ChargerIndex%20UK.html

The tests, teardown sand authors comments show what a minefield the USB PSU market is for the buyer !

The really scary issues include the use of non Y spec capacitors between primary and secondary sides and insufficient creapage distances. Basically, you can buy a nasty cheap or fake USB charger and take your life in your hands. Even some branded units have safety issues according to the comments on the site.

The site has a section that describes what is found within a typical USB power supply, what cost savings are commonly made in cheap units and the dangers of unsafe component types used in some….. such as 1000V ceramic capacitors that are not safety rated Y2 types.

https://lygte-info.dk/info/SMPS%20workings%20UK.html

The voltage sag and current capability testing is also interesting to see. Well worth a visit.

Fraser

[BBBbbb]

I think it's been featured here a few times in various discussions and (I'm not quite sure) the person behind it is/was on this forum as well.
Great resource, I always check it out when looking for new chargers.

[tunk]

He's a eevblog member, HKJ.

You could also look at some of DiodeGoneWild's videos:
https://www.youtube.com/playlist?list=PLfUGOPyKWwiriWhjmdtvjBw_J7X_X5OnU
And Big Clive recently tore down one:
https://youtu.be/rwEh4jsVew0

[Gyro]

The really scary issues include the use of non Y spec capacitors between primary and secondary sides and insufficient creapage distances. Basically, you can buy a nasty cheap or fake USB charger and take your life in your hands. Even some branded units have safety issues according to the comments on the site.

The site has a section that describes what is found within a typical USB power supply, what cost savings are commonly made in cheap units and the dangers of unsafe component types used in some….. such as 1000V ceramic capacitors that are not safety rated Y2 types.

The worst bits are the ones you can't see! Some of DiodeGoneWild's videos, including transformer teardowns, are quite horrific, with single insulated enamelled primary and secondary wires crossing each other, and in one case, no inter-winding tape of any description!* You don't see triple insulated wire in any of them, other than verified genuine main brand PSUs.

It's getting to the point where you need to buy two adapters, one to completely tear down and one to (hopefully) use.


EDIT: * (Transformer starting at 11:00)

[tunk]

There's also this youtube channel: https://www.youtube.com/c/ChargerLab/videos