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  1. Generic 1A USB Car Charger Teardown, Generic 1A USB Car Charger Teardown: шаг 1, изображение 1 из 1
    • Here we see the device. It is predominately cheap plastic and thin stamped metal.

    • It looks and feels very light and cheap, not a good sign. Though as they say don't judge a book by its cover.

  2. Generic 1A USB Car Charger Teardown: шаг 2, изображение 1 из 1
    • Remove the two screws on the front with a #00 Philips screwdriver.

    • One of the screws is hidden underneath the label.

    • Be careful as these screws are very small and the plastic they screw into is VERY weak. If you over tighten the screws they will strip out.

    • Pry off the metal end cap. It should come off pretty easily.

  3. Generic 1A USB Car Charger Teardown: шаг 3, изображение 1 из 2 Generic 1A USB Car Charger Teardown: шаг 3, изображение 2 из 2
    • Unscrew the metal ring at the top and remove the parts.

    • Only a spring and no fuse inside. Not good at all. This means that it is relying on the fuse for the power port.

  4. Generic 1A USB Car Charger Teardown: шаг 4, изображение 1 из 3 Generic 1A USB Car Charger Teardown: шаг 4, изображение 2 из 3 Generic 1A USB Car Charger Teardown: шаг 4, изображение 3 из 3
    • The device the pulls apart leaving you with a VERY sparsely populated insides.

    • I see two capacitors, an inductor, an LED, a usb port, a diode and the power connectors. Still no fuse or any othersemblance of protection circuitry.

  5. Generic 1A USB Car Charger Teardown: шаг 5, изображение 1 из 2 Generic 1A USB Car Charger Teardown: шаг 5, изображение 2 из 2
    • Lets look at the other side. Holy Long Leads Bat Man! Those leads (in the red box) are WAY too long. Compare their length to the ones on the USB connector (in blue). While the soldering looks OK, the long leads show a general lack of attention to detail and cutting of costs.

    • Now we get a good look at the circuit board in general. The more signs of cost cutting. The solder mask (the stuff that makes the PCB green) has huge empty spaces around the solder pads. You can clearly see the brown PCB through there. This increases the risks of short circuits etc. Once again cheap design.

    • The main IC seems to be an MC34063 switching regulator. A veritable workhorse in USB chargers. While this IC can drive up to 1.5A it is only considered good for up to 700mA continuous before heat becomes an issue. Uh oh.

  6. Generic 1A USB Car Charger Teardown: шаг 6, изображение 1 из 1
    • Now lets look at the schematic and see how it compares to the datasheet.

  7. Generic 1A USB Car Charger Teardown: шаг 7, изображение 1 из 2 Generic 1A USB Car Charger Teardown: шаг 7, изображение 2 из 2
    • Here we see the stock schematic from the database.

    • In the next image we see the schematic used in the device. We see many values have changed.

    • The biggest change is that Rsc is 0.22ohms. This gives an Ipk of 1.36A, which gives an Iout Max of 0.68A. This is FAR from the quoted 1A.

    • Also, the input and output capacitors have been reduced in size to 10uF and 100uF respectively. This means that we will see MUCH larger ripple on the output. Possibly falling out of USB spec and putting the attached device at risk.

    • Quite simply, the device is a rebadged 500mA or 750mA USB charger at best. It is NOT 1A capable, despite what the sticker on the body says.

PedroDaGr8

Участник с: 08/12/12

2 971 Репутация

Автор 15 руководств

11 Комментариев

I tore down the same device with much the same comments - http://mm0hai.net/blog/2012/08/01/Messag...

River MacLeod - Ответить

Could you do a tear down of the more advanced usb car chargers, it would be interesting on how these are made and work

http://www.amazon.com/Charger-Adapter-iP...

Alpha80mega - Ответить

I do have one of these babies ... unfortunately , so if I replace all the components like in the original schematic from data base , everything should work fine , wright ?

xavialfon - Ответить

The right conclusion of R(3.6K) it has to be connected to the right conclusion of L (220uH).

Alexander Vladlog - Ответить

I have already ordered a charger from the best seller of Amazon

http://www.amazon.com/gp/bestsellers/ele...

allisonfranz - Ответить

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