Nillkin/Jelly 2-port USB car charger

DSC_3019

Official specifications:
I got it from ebay dealer xinghaishi44

DSC_3002 DSC_3003

I got this car charger in a retail package, there where no accessories or manual included.

DSC_3020 DSC_3021

There is blue led between the two usb connectors.

DSC_3022 DSC_3024 DSC_3025






Measurements


Load%20sweep%2011.6V
Load%20sweep%2014.6V

The efficiency is good, but I am missing an overload protection. I also did a fast check at 5A and the output was not turned off. The output voltage is rather high.

Load%20sweep%2024.0V

At 24 volt the efficiency is slightly lower, but still good. The output voltage starts even higher.

Voltage%20sweep%203.4A%20input%20current
Voltage%20sweep%203.4A

At full load the efficiency is best with 24 volt and drops a but when the voltage goes down.

No%20load%20voltage%20sweep

With no load it can maintain output voltage down to 5.5 volt.

Load%20test%203.4A

There is no problem running for 1 hour at full load, the bumps in the curve at 47 minutes is because I am moving it around to take the IR photos.
The temperature photos below are taken between 30 minutes and 60 minutes into the one hour test.

Temp2824

M1: 41,8C, M2: 47,9C, HS1: 58,2C
It gets fairly warm.

Temp2825

M1: 38,9C, M2: 52,8C, HS1: 54,3C

10ohm

At 0.5A with 24V input the noise is 14mV rms and 120mVpp. All noise values are low and only changes slightly with input voltage, this is good.

5ohm

At 1A with 24V input the noise is 14mV rms and 120mVpp.

2ohm

At 2.5A with 24V input the noise is 15mV rms and 109mVpp.

1ohm

At 5A with 24V input the noise is 18mV rms and 134mVpp.

5ohm12V

At 1A with 12V input the noise is 10mV rms and 129mVpp. These values are very close to the 24V values for all loads.



Tear down

DSC_3121

I could pry the front lid off the charger, remove two very small screws and pull it apart. The two side connection made the pulling apart rather difficult.

DSC_3122

The controller chip is a GS9206, it can deliver up to 6A output current and contains two fet transistor to handle the switching, i.e. it has synchronous rectification.

DSC_3123

On the other side of the circuit board there is only the inductor.

DSC_3124

DSC_3125 DSC_3126

There is only two connections from the switcher to the the usb connectors and no parts on this side of the usb circuit board.

DSC_3127 DSC_3129

On the usb side there is a led with series resistor for the led and coding resistors for the usb connectors

DSC_3130 DSC_3131

There is space for one more led and there is a small capacitor.

DSC_3132

The led has some black heat shrink around it, to secure the light only is visible from the hole for the led, not in the usb connectors.


Beeing a 12/24V device there is no need to test with high voltages.



Conclusion

This car adapter delivers lots of power with low noise, but I do not like the high voltage or the missing overload protection. I also wonder about the usb coding, I would have expected one DCP coded port.

This adapter is fairly good.



Notes

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