BlitzWolf 40W 5 port usb charger

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Official specifications:
I got it from Banggood SKU212468 (White version SKU212420).

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I got this charger in a minimally labeled cardboard box.

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Contents was charger, mains cable and instruction sheet.

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Measurements


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Good efficiency and stable output voltage (The voltage drop is mostly due to usb cable and connections resistance).
No individual overload protection, but in tear down it can be seen that there is a fuse on each output that will blow if there is a serious overload.

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Running all ports in parallel it turned the output off just befoere 9A, this looks very sensible for a 8A rated device.

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The charger has no problem with a total load of 8A for one hour.
The temperature photos below are taken between 30 minutes and 60 minutes into the one hour test.

Temp2125

M1: 71,3C, M2: 65,5C, M3: 57,4C, M4: 52,9C, HS1: 74,3C
HS1 is the rectifier diodes, M1 is the transformer and M2 is the mains switcher heatsink.

Temp2126

M1: 56,9C, M2: 60,3C, HS1: 66,4C
HS1 is again the rectifier diodes.

Temp2128

M1: 57,3C, M2: 52,1C, HS1: 62,5C
HS1 is the heatsink for the rectifier diodes.

Temp2129

M1: 46,7C, M2: 52,5C, HS1: 57,5C
HS1 is the heatsink for the rectifier diodes.

10ohm

There is not much noise at 0,5A with 12mV rms and 140mVpp.

2ohm

The noise is fairly constant with increasing load: 12mV rms and 180mVpp.

0.6ohm

Even at maximum load: 14mV rms and 160mVpp.



Tear down

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I could not break it open and had to cut it.

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A few parts can be seen here, the mains switcher transistor on a heatsink and the two rectifier diodes on their own heatsink.
The optical feedback chip is also visible.

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On this picture one of the common mode coils are visible. There is a bridge rectifier under the heatsink, but it is not visible.
The safety capacitor with all its approvals can also be seen.

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The black paper between the transformer and heatsink is a way to improve isolation.

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The mains switcher IC (U1) and the feedback control IC (u2) can be seen. There is a fuse for each output.

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The distance between low volt side and mains is enough.



Testing with 2500 volt and 5000 volt between mains and low volt side, did not show any safety problems.



Conclusion

This box has lots of usb power and a safe construction. The noise is low and the voltage constant even at full load.
All in all a good usb power supply.



Notes

The charger was supplied by Banggood for a review.

Read more about how I test USB power supplies/charger