2A Dual port USB



Official specifications:

• Input: AC 100-240V, 50/60Hz
• Output: 5V 2.1A

I got it from Ebay dealer: cici10086











Measurements

• Do not fit standard mains outlets
• Power consumption when idle is 0.08 watt
• Usb outputs are with unknown coding.
• All outputs are in parallel.

Each output can deliver 1A before output voltage drops, there is no overload protection.



And because they are in parallel the total output is also 1A.



I could draw 1A for 1 hour without any problems.
The temperature photos below are taken between 30 minutes and 60 minutes into the one hour test.



M1: 40,3°C, HS1: 47,7°C
HS1 must be the transformer.



M1: 44,6°C, M2: 47,6°C, HS1: 61,5°C



M1: 35,8°C, HS1: 45,9°C



M1: 45,1°C, HS1: 49,6°C
HS1 must be the transformer.



M1: 43,3°C, HS1: 76,0°C



Noise at 0.5A load is 129mV rms and 670mVpp



Noise at 1A load is 217mV rms and 1080mVpp





Tear down



A hit with my mallet and it was open, nothing is glued together, it is only clips.



There is a bridge rectifier hidden under the capacitor. The design uses two transistors and has a blue capacitor of 1000 volt type that will short when overvoltage is present (Very bad). There is also a opto coupler and a rectifier diode.





Here the markings on the blue capacitor can be seen and the bridge rectifier below the big capacitor.



The two transistors are on this side of the circuit board.



There is only a few resistors on the other side of the circuit board.






There is supposed to be about 6mm between low volt side and mains, here is only 1mm.

The charger failed a 2500 volt test and shorted between low volt side and mains, this makes the charger dangerous everywhere.


Conclusion

This charger has very bad safety, stay away.



Notes

Index of all tested USB power supplies/chargers
Read more about how I test USB power supplies/charger