Dual USB Wall charger Keke-F5

DSC_1637

Official specifications: I got it from ebay dealer ddarlingshop

DSC_1609

It was packed in a plastic bag inside the usual envelope.

DSC_1610

DSC_1611

DSC_1612

Behind the two green teardrops (one on each side) is a led.

DSC_1613 DSC_1614 DSC_1615




Measurements

Dual%20USB%20Wall%20charger%20Keke-F5%20%231%20230V%20load%20sweep

The charger can deliver 1A, not the rated 2.1A

Dual%20USB%20Wall%20charger%20Keke-F5%20%232%20230V%20load%20sweep

It is the same on the other port.

Dual%20USB%20Wall%20charger%20Keke-F5%20230V%20load%20sweep

And when using the ports in parallel.

Dual%20USB%20Wall%20charger%20Keke-F5%20120V%20load%20sweep

Using 120VAC gives the same result.

Dual%20USB%20Wall%20charger%20Keke-F5%20230V%20load%20test

Running 1 hour at 1A worked fine.
The temperature photos below are taken between 30 minutes and 60 minutes into the one hour test.

Temp5882

M1: 56.8C, HS1: 58.7C
HS1 is the transformer and M1 is the rectifier diode.

Temp5883

M1: 44.1C, HS1: 53.3C

Temp5884

HS1: 44.1C

Temp5885

M1: 53.3C, HS1: 57.0C

10ohm

At 0.5A the noise is 97mV rms and 688mVpp.

5ohm

At 1A the noise is 114mV rms and 635mVpp.



Tear down

DSC_1930

Placing the charger in my vice and whacking one with my mallet did open it.
The green teardrops was not glued and if they fall out the charger is very dangerous to touch.

DSC_1931

On this side is the input fuse (RF1: Fusible resistor), a bridge rectifier, the two leds and a large rectifier diode.
The "blue safety capacitor" is not a safety capacitor, but just a 1000V capacitor.
It is interesting to see the circuit board is marked 1A, this matches the output of the charger, but not the external marking.

DSC_1933

DSC_1934 DSC_1936

DSC_1935

DSC_1932

On this side it the mains switcher.

DSC_1938

DSC_1937

Creepage distance is about 2mm, this is way to short.


Testing with 2830 volt and 4242 volt failed the 4242V test, this means it is unsafe in 230V countries.



Conclusion

The charger is a 1A charger with a lot of noise.
Too short distance between mains and usb, together with a unsafe capacitor, this rather bad safety.

Stay away from this charger.


Notes

Index of all tested USB power supplies/chargers
Read more about how I test USB power supplies/charger
How does a usb charger work?