Test/Review of Power cube

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HKJ
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Joined: 05/24/2011 - 12:23
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Location: Copenhagen, Denmark
Test/Review of Power cube

Power cube
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Official specifications:


  • Four mains outlets
  • Dual USB Ports: 2A 5V
  • Product weight : 0.612 kg
  • Product size (L x W x H) : 7.4 × 7.4 × 7.4 cm / 2.91 × 2.91 × 2.91 inches

I got it from gearbest.com, but I could also have got it locally.
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The pack contains the power cube, a mounting bracket with double-sided sticky tape and a multilingual instruction sheet.
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Mounting bracket uses one of the sockets.
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The power cube exist in multiple versions, both with and without extension cord and with or without usb output.
Measurements


  • Power consumption when idle is 0.15 watt
  • Usb output is coded as Apple 2.1A
  • All outputs are in parallel.
  • Earth is not connected to usb shield.

Power%20Cube%20top%20load%20sweep
Power%20Cube%20bottom%20load%20sweep
About 2.5A on each output, this looks fine for a 2.1A rated device.
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Sadly the outputs are in parallel and the 2.1A is for both outputs together.
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I could draw 2.1A for 1 hour without problems.
The temperature photos below are taken between 30 minutes and 60 minutes into the one hour test.
Temp3055
M1: 43,7°C, M2: 44,3°C, HS1: 51,8°C
Temp3056
M1: 38,6°C, HS1: 52,5°C
Temp3057
M1: 43,5°C, HS1: 45,5°C
Temp3058
HS1: 46,3°C
Temp3059
M1: 62,8°C, M2: 51,1°C, HS1: 73,0°C
HS1 is the transformer getting hot. M1 is the rectifier diode.
10ohm
Noise at 0.5A load is 55mV rms and 714mVpp, generally a lot of peak noise.
5ohm
Noise at 1A load is 78mV rms and 661mVpp
2.5ohm
Noise at 2A load is 107mV rms and 803mVpp
Tear down
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The plate covering the screws could be removed, it used clips.
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The sockets and wire assembly can slide out (with some pressure) when the cube is open, But I would have to desolder the orange wires to do it.
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There is a resistor as fuse at the input, a inductor between the two mains capacitors. U1 is the switcher. The blue capacitor is the safety capacitor and D7 is the rectifier diode.
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D1 to D4 is the mains bridge rectifier build with diodes.
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The small circuit board with usb connectors has 4 coding resistors, the two usb connectors shares them.
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The distance between mains and low volt side is very good with the slot (Distance must be minimum 4mm).
Testing with 2500 volt and 5000 volt between mains and low volt side, did not show any safety problems.
Conclusion
I am not that impressed with the power cube concept, I do not like wires in all directions.
I am even less impressed with the usb output, it has a lot of noise, fixed Apple coding and only power enough for one (high current) device at a time.
The usb output is safe and works acceptable, but gets fairly hot when fully loaded.
Notes
Index of all tested USB power supplies/chargers
Read more about how I test USB power supplies/charger

My website with reviews of many chargers and batteries (More than 1000): https://lygte-info.dk/