Test/Review of Linoya A3 4 Ports 4A USB USC-001

Linoya A3 4 Ports 4A USB USC-001

Official specifications:

  • 4 USB outputs
  • 5V / 2A (Max.) charging port suitable for iPad, tablet or other high power required devices.
  • 5V / 1A charging port suitable for iPhone, cellphone and other USB powered devices.
  • LED indicator light for power status, safety and convenient.
  • Input: Wide input voltage range of AC 100-240V for use worldwide.
  • Interface: USB2.0

I got it from gearbest sku:13039901

I got this charger in a cardboard box.

The box only included the charger and a main lead with US plug.

The black border is a rubber band.


  • Power consumption when idle is 0.19 watt
  • Outputs are in parallel.
  • 2A port is auto select up to Apple 2.5A
  • 1A port is USB power (DCP)
  • Blue led is on when usb power in on.

No individual overload protection on the ports, each port can deliver the full current.

When using all outputs, the voltage drop in connections and cables are lower.

No problem with full output current for one hour.
The temperature photos below are taken between 30 minutes and 60 minutes into the one hour test at 3.5A.

M1: 32,9°C, M2: 71,4°C, M3: 53,9°C, HS1: 75,5°C
HS1 is the transformer. I wonder what M2 is, it looks like a capacitor, but they are not supposed to get hot.

M1: 58,2°C, M2: 45,8°C, HS1: 62,3°C

M1: 53,0°C, M2: 46,3°C, HS1: 60,7°C
The heatsink on the rectifier diode spreads the heat over a big area (very good).

M1: 50,5°C, M2: 68,6°C, HS1: 73,3°C
HS1 must be the 0.022ohm resistor (R4), but it is only 0.35watt that is must get rid of?

At 0.5A the noise is 23mV rms and 900mVpp, that is a lot of peak noise.

At 2.5A the noise is 25mV rms and 800mVpp

At 4A the noise is 17mV rms and 420mVpp, at full load the noise is a bit lower.

Tear down

This time I checked under the rubber feet and found the screws.

On the top side there is an input fuse, a common mode coil, the mains switcher transistor hidden under a small heatsink. There is also a safety capacitor and opto feedback with a slot in the circuit board below them.
On the low volt side there is the rectifier diode hidden below a larger heatsink and a inductor.

From this side the safety capacitor can be seen.

On the mains side the common mode coil is visible, on the low volt side the blue led is visible.

A significant part of this side is the heatsink for the rectifier diode.

There is a few interesting parts here, the rectifier diode bridge (BR1), the mains switcher controller (U1).
On the low volt side there is the voltage feedback controller (U2), the resistor R4 is probably used for the over current protection.
Below the 2A usb connector is the auto mode chip (U3), but also space for fixed coding.
The other usb connectors has space for any coding and uses the DCP coding (R2, R43, R44).

There is more than enough distance on the circuit board, below the opto coupler the distance is shorter, but that is fine because of the slit in the circuit board (Even without the slit the distance had been enough).
On the topside the distance is shorter, but there is some isolation. I did not have any problems with it.

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


The construction is decent, it can deliver the rated 4A. It can charge one pad and 3 phones at a time (As long as they are not all completely empty and trying to draw maximum current).
I only have two complains, one is too much noise in the output, the other is the rubber band design. It is not the black border I complain about, but that it is done with a rubber band!


The usb power supply was supplied by gearbest for a review.

Index of all tested USB power supplies/chargers
Read more about how I test USB power supplies/charger

Thanks for the Review HKJ! At least there were screws under the rubber band :bigsmile:

Did the IKEA charger “koppla” managed to get in your queue?

I find the ability to plug in 5 amps (3 ports at 1amp, and 1 port at 2amps) worth of items to be a little at odds with the rated capacity of 4 amps. Sounds like an invitation to a problem. Or does a voltage drop happen in that case? If there is a voltage drop, what is the danger to the connected equipment?

I got a box from Ikea and I believe it contains the usb charger and a couple of batteries, but I have not checked.

Not that much of a problem, who is going to plug in 3 empty phones and a empty pad at the same time? I the equipment is plugged in over a timespan of a few hours it will not be a problem, because some of the equipment will be charged enough to reduce the charge current.

If too much equipment is plugged in the A3 will shut down and restart again shortly after. This will mean that all connected equipment will go in and out of charge mode all the time, this is easy to see and then remove a device.

Can you give us a little comment about this noise? Some of us are not familiar with electrical “noise”. For instance, is it audible? And what is the danger of electrical noise?

Usual it is not audible, but it depends on the connected equipment.

  • In rare cases it can damage connected equipment.
  • Sometimes it will make the connected equipment malfunction, like the touch screen stops working or works wrongly when connected to the charger.
  • Depending on the kind of noise (I do not analyse for this) it may also partial jam the receiver, i.e. make it less sensitive. This means that if you have a weak signal your phone will not work when connected to the charger.
  • Most of the time it does not really do anything significantly.

I have once tried a charger where my phone stated giving random presses on the touch screen. I was a bit worried about the phone, but it survived without any damage. After that I stopped connecting it to cheap chargers.

This charger does look nice, and the rubber band may help to soften a drop to the cement. :slight_smile:

I do also believe it is one of the better looking usb chargers (But not good looking).

Not really, you have the plastic sticking out at the edge to keep the rubber band in place, i.e. the plastic will take the hit.

Good news! :slight_smile:

(it´s made in China)

Nice review, shame about the noise, though I am not really worried, I got the blitzwolf one you reviewed a while ago and am just about to buy another so i don’t have to move the one in my room when I travel.

That’s the first time I’ve ever heard anyone say that…

The good news is that HKJ got the box, nothing else :slight_smile:

Hi HKJ and thanks again for all your interesting reviews :wink:

received today the sku:13039901

I received a different product though. Black, no rubber band and it’s longer and has a switch on it. The model number on the label on the back is different, USC-004 instead of USC-001.

Unfortunately it’s not possible to open it without destroying the case, it’s die-cast. I wonder if it’s the same electronics inside with just an added switch or not… I think the differences may be more than that cause the led is in a different position. The barcode label on the box is identical but that’s the GB sku code.

Have you checked for screws under the rubber feet and under the label?

the label is flat to the touch, no screws underneath… I’ll check the rubber feets but I doubt there’s any screw, the plastic case looks casted/welded

EDIT: you were right! there are 4 screws under the rubber feets… the split line between the two shells of the case was so tight that it looked like they were welded together… very good build quality :slight_smile:

Very strange, ther borders are now free, but there is something that locks the case and prevents it from opening. It looks like it’s something near the center of the pcb, in the area near the 2A port (I can lift the border all around the perimeter so there should be no plastic hooks in the perimeter, but the cover is still locked in place).
Was it like that also on your model? was there maybe hot glue or something similar?

Could it be another screw under the label (It is not always possible to feel them)?


ok thanks, I’ll try again tonight

edited out….working perfectly today…only some problems in camera app…

finally made it to the pcb :stuck_out_tongue:
those 2 plastic pins around the middle of the shell were glued :s

It looks identical to me, except for those two filter capacitors from the mains to ground. What do you think?