still this charger I found something interesting:
on USB-A port, we use the same USB tester/charger/data cable/phone to test the charging current, and the results differ so much.
So we need to find out the reason.
Today we will talk about the USB interface, and USB2.0 and USB3.0 interface are the main characters. We need to know the basic knowledge of them:
In appearance, under normal circumstances, the USB2.0 interface is mainly white/black, and the USB3.0 interface is mainly blue. We can see the interface as shown in the figure.
Secondly, their icons are different. We can see that the icon of USB2.0 is like this:
And this is for USB3.0
Structurally, the USB 2.0 interface is a 4-pin design, while the USB 3.0 interface is a 9-pin design.
Finally, the transmission rate:
the USB2.0 transmission speed is 60MB/S, and the USB3.0 transmission speed is 625MB/S, almost 10 times higher than USB2.0.
The USB3.0 interface is normally compatible with USB2.0. , let's get to the topic.
Today's case is an accidental situation we have been looking for for a long time. You know that we produce USB testers, UM24(C) and UM25(C) support USB2.0, and UM34(C)/AT34/AT35 support USB3.0
We have sold thousands of USB testers so far, and we have received more than 99% 5-star recommend, but some customers have reported that one problem is that they use our AT34 tester to connect the charger and mobile phone, and found that the phone can not charge. Or the mobile phone charging current is very small, then they used the UM25C back to find that the charging current is normal, so they think the quality of the product itself is bad and returned the product. We received the returned products and we had a test on them, find that the function is completely normal without any problem. I believe that customers will not lie to me, but I have always remembered this matter.
Until recently I finally meet this problem again, I have always had a habit of plugging a USB tester into the charger to see the charging current. Usually I use the UM25C to test.
However, I recently bought UGREEN charger, and I have made a test video about it. The 18W quick charge on USB-C port is very easy to use. But don't forget that it also has a USB-A output. I used the UM25C in the video and found no problems. Until yesterday I used the AT35 to find that the charging current of the phone is very small. I realized that I might have met the same situation.
I prepare 2 chargers(HUAWEI charger and UGREEN charger) and 3 USB testers(UM25C, UM34C and AT35)
And we can get the charging voltage and current here:
Then we still use the same USB tester and same UGREEN charger to test again. But this time we don’t insert all the male port into the charger
and we get new data:
Only the USB3.0 interface USB tester the current decreases. USB2.0 interface USB tester still test the same result.
So I think you have find out the reason, the output of the charger has problem.
According to the structure of USB3.0, it can be used to connect USB2.0 port and under normal circumstance it has no problem but if their contacts don’t match, it will cause problem.
We can see the structure of the UGREEN charger
The interface of the first picture matches the USB3.0 interface pin, and the second contact exceeds the normal contact range, which causes the problem of small current flow. When we pull out a little tester.After the contacts point are correctly matched, the current returns to the normal value.
Therefore, when we find such an accident, we can use the exclusion method to determine the problem and solve the problem.
This type of USB interface is not common, but there are also such situations, so don't make a decision easily when the problem occurs. Please analyze it calmly and solve the problem scientifically.
Ok, so much to say today, thank you.