AIFECT 5V1A Mobile phone charger WHA-1U-5W
Official specifications:
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Input: 100V - 240V
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Output: DC5.0V 1A (5W)
I got it from ebay dealer orico_daily_deal
Measurements
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Power consumption when idle is 0.07 watt
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Usb output is coded as usb charger (DCP)
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Weight: 29.8g
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Size: 76.2 x 37 x 21mm
The charger can deliver 1.1A, the voltage drops slightly before the 1A, but still within tolerances.
At 230VAC it is more stable.
Running the charger with 1A for one hour worked fine.
The temperature photos below are taken between 30 minutes and 60 minutes into the one hour test.
M1: 47.1°C, HS1: 63.1°C
HS1 is the mains transformer.
M1: 50.8°C, M2: 44.0°C, HS1: 52.6°C
M1: 58.0°C, HS1: 61.4°C
HS1: 56.0°C
M1: 43.0°C, HS1: 62.1°C
At 0.5A the noise is 24mV rms and 197mVpp.
At 1A the noise is 29mV rms and 184mVpp, this is low noise
Tear down
Some pressure with my vice and a bit breaking with a screwdriver and the lid was off.
There is a fusible resistor (FR1) as fuse, two mains smoothing capacitors (C1 & C2) with a inductor (L1) between. Between mains and low volt side is the usual safety capacitor. The transformer has extended leads on the low volt side to increase creepage distance. The UL code on the circuit board is for the circuit board itself, not the electronic on it.
On this side is the bridge rectifier and the switcher (U1: OB25133 5W). On the low volt side is the rectifier diode (D3) and for some reason somebody has cut into it (May have been the pressure when I opened it). This diode is not very large and do not need to be on a 1A power supply.
The isolation distance is nearly 6mm, this is slightly low, but nothing serious.
Testing with 2830 volt and 4242 volt between mains and low volt side, did not show any safety problems.
Conclusion
The charger can deliver the rated current, has a good coding and low noise. Safety is acceptable.
Notes
The charger was supplied by a reader for review.
Index of all tested USB power supplies/chargers
Read more about how I test USB power supplies/charger
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