This charger is a older good quality charger from a name brand, use this review to see how it is build and compare performance to the cheap brands I test.
A very compact design.
Measurements
Idle power is 0.025 watt, this is very good.
When overloaded the output voltage will drop, then turn off.
Output is coded as USB charger (DCP)
Difficult to open (This is good).
Output voltage is very stable and the efficiency is around 75%, the overload protection kick in between 1.3A and 1.4A.
One hour with 1.2A load is not problem.
The temperature photos below is taken between 30 minutes and 60 minutes into the 1 hour test.
M1: 47,3°C, M2: 47,9°C, HS1: 61,9°C
The warm spot looks like the inductor L1.
M1: 47,4°C, M2: 55,2°C, HS1: 63,2°C
The hot spot here is Q1, the switching transistor.
M1: 54,3°C, M2: 49,4°C, HS1: 56,3°C
M1: 49,6°C, HS1: 66,2°C
There is not much noise, 13mV rms and 300mVpp. at 1.2A.
At 0.5A the noise is lower with 8mV rms and 180mVpp.
Tear down
The main capacitors has a 105°C temperature rating, this is good.
There is a seperate shield between the mains transformator and the low volt side, this shield does also have moulded cavities to support the capacitors.
The only connection from mains to low volt side is the two low volt wires that goes over the shield.
The resistor is probably a fusible resistor, i.e. it is designed to work as a fuse.
The two areas with "fingers" is the mains connection, when the circuit board is pushed into the housing, it will connect to the mains pins.
BD1 is a bridge rectifier.
The orange stuff around SR11, is probably to improve isolation.
The shield goes through the circuit board and does also provide extra isolation on this side.
This circuit does not have any optical feedback to control the voltage.
Because of the shield, there is more than enough isolation distance.
Testing the mains input with 2500 volt and 5000 volt between mains and low volt side, did not show any safety problems.
Conclusion
It is interesting to see how a big brand usb power adapter is designed and works.
Notes
The power supply was supplied by Erik from Finland for review.
Most USB and laptop adapters operate under universal voltage, and this one in particular says it also works with 100V.
HKJ, do you know how current negotiation (1A to 2A) through USB works? I’d love to know how a phone determines how much current to draw when charging, because newer phones seem to draw 2.0A. What would happen if one of those phones were to be plugged into this charger?
As long as the charger is in free air, it is not needed, but it will increase the lifetime of the charger.
Some electronic parts deteriorate faster at higher temperature (that is very obvious with screens where it is the same parts that fails nearly every time). Keeping them cooler will extend their life, a rule of thumb says 10 degree lower is double lifetime.
You really need to use you charger many hours for many years before this has any relevance, just charging a phone once each day for a few years is probably not enough to hit this problem.
Thank you very much, I really need one like this one, because my usb power supply go hot very fast (I use it with my Wiko Iggy smartphone everyday).
it’s hard to find it original and not a copy?
Any guess what’s indicated by the variations in the name?
I see models differing in just the last 2 letters — there’s a “WR” and others
I also see “LG MCS-02” versions
(“LG MCS-02WT MCS-02WD” at Amazon)
(“LG MCS-02W/SGDY0017903” also at Amazon)
some with and some without a bundled USB cable
I looked at LG’s pages but don’t see any clarification about what’s what.
(I did try emailing LG’s support; I’m guessing these are just so old they don’t even show under their “discontinued” items page)
There are at least two different manufacturers of these LG 1.2A chargers: SUNLIN (as in the review) and DONGDO.
I have a few that looks exactly like the one in the review but it says made by DONGDO and the model is LG MCS-01ED. I had one from SUNLIN too but I don’t have it anymore, it probably was LG MCS-01ER as in the review. I have one with UK plug instead of euro plug which is model MCS-01UR and is made by SUNLIN.
There are LG 1.8A chargers too, I have the MCS-04WR with US plugs which looks like this charger but is just bigger. It’s made by SUNLIN.
LG replied to my email saying these are OEM products that would have been bundled with various kinds of phones originally, some years ago.
Makes sense, I found one on eBay and it’s thoroughly covered with little scratches, it’s been around a while.
Could you tell me what the resistor across ac terminals is for?
I have an LG 9v fast charger with that resistor damaged. Its a wire wound resistor in it. I kindf need help replacing it.
There is no resistor across the AC terminals, but a fuse (Fusible resistor) in series with the AC input. If that is blow it is very likely that something else is blown also (Either switcher controller or switcher transistor or both).
Yes its not between the terminals(sorry there) And Thanks for the response. Its probably not possible to replace the controller right?, I’ll probably buy a new adapter.
Thanks
