Samsung USB 5V 0.7A ETA0U10EBE

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Official specifications: A reader got this charger with his phone, i.e. it is a original and it is fairly old.

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Measurements

Samsung%20USB%205V%200.7A%20230V%20load%20sweep

The charger can deliver a bit above 0.8A, this is fine for 0.7A rated charger.
There is some cable compensation or the voltage would have dropped significantly when loaded.

Samsung%20USB%205V%200.7A%20120V%20load%20sweep

And it can deliver exactly the same on 120VAC

Samsung%20USB%205V%200.7A%20230V%20load%20test

And the charger has no problem delivering rated current for one hour.
The temperature photos below are taken between 30 minutes and 60 minutes into the one hour test.

Temp6649

HS1: 57.2C
HS is the rectifier diode.

Temp6650

HS1: 54.1C

Temp6651

HS1: 50.8C
On this side HS1 is the transformer.

Temp6652

HS1: 56.0C

Temp6653

HS1: 55.5C



10ohm

At 0.5A the noise is 30mV rms and 358mVpp.



Tear down


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I mounted the top of the charger in my vice and gave it a whack with my mallet, then it was open.

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On this side there is a fusible resistor (F1) at the mains input and a inductor (L1) between the two mains smoothing capacitors (C1 & C2). The mains switcher transistor (Q1) is a small one.

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On this side is the bridge rectifier (BD1), the mains switcher controller (IC1) and the rectifier diode (D2).

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The distance between mains and low volt side is about 5.5mm, this is slightly low.


Testing with 2830 volt and 4242 volt between mains and low volt side, did not show any safety problems.



Conclusion

This is a fairly weak charger with only 0.7A charge current, when the low current is enough the charger works fine.



Notes

The charger was supplied by a reader for review.

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