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Comparison Between Genuine And Imitation Cell Phone Charger

By on October 1, 2012

The cover of the imitation charger is exactly like the genuine one with the Sony Ericsson words engraved on it. I opened the imitation charger by using a saw, a knife and a hammer. First, I used the small saw to deepen the gap between the top and bottom covers. Next I used a knife to force on the gap. After that I used a hammer to knock it out. There was no crack and all the edges were intact and can be easily glued it back.

There are big differences between the original and imitation circuit boards. The imitation one used much less components and this is the reason why it is much cheaper as compare to the original one. The original one has the design of a switch mode power supply where it has the regulation circuit.

The imitation charger circuit board

This is what I have observed on the imitation charger:

1.     It does not have a bridge rectifier to rectify the incoming 220 Vac. It uses only a single 1N4007 to do the rectification job which is very unstable

2.     No IC or any transistor were used to regulate the voltage

3.     I found only one 5 Volt zener diode to regulate the voltage

4.     Using a Mosfet 3001 for switching in the primary side and in the output secondary side it used 1N5819 Schottky diode for rectification purpose to get the DC output voltage.

5.     In the primary side the main filter capacitor value was 2.2 uf 400 vdc and in the secondary side there was a filter cap with the value of 22uf 25 volt.

The original charger circuit board

By comparing on these two charger circuits one can easily tell how many components were used on each charger.

The disadvantage of the imitation charger is that the output voltage have ripple and it is a not a clean DC. This pulsating DC voltage could harm the genuine battery and a prolong use can destroy the battery. If the phone owner uses the imitation charger they might think that the battery is the problem but actually is the phone charger that causes the problem. Not only imitation phone charger can be found in the market, fake batteries also easy to get and they are cheaper than the genuine batteries.

The bad DC output waveform

As you can see from the picture above, the DC output contains the AC ripple. The reason for it is because the imitation charger uses only one single diode for rectification. It should have use four diodes instead of single diode. This single diode usage that produces the ac ripple will surely ruin the battery life.

The good DC output waveform

The above photo shows the good DC waveform of the original phone charger.


I suggest that if your original phone charger have problem, you repair it on your own. If you do not wish to repair it then do yourself a favor and get the original charger and not the imitation one.






Article by Beh from Iran and special thanks to his friend Mr Hesam for the help in preparing the article.


Note: Please do not attempt to perform the repair work if you do not know about electrical safety. 

If you have any interesting repair article that you want to share to others please do email me.

I encourage you to leave your comments on the post, as well as share the post with anyone you feel may benefit from it using the social media buttons below-thanks.

P.S– If you want to learn how to be a professional power supply repairer please click HERE for more information. 

P.P.SClick here to read the first post by Beh




  1. elitechz

    October 17, 2012 at 3:35 am

    Sir, I appreciate your tutoring,you are my mentor I must confess:may God give you more knowledge and grace.You are my master!

  2. beh

    October 17, 2012 at 4:05 am

    HI OKORE you welcome. beh

  3. Lex

    October 24, 2012 at 10:22 am

    I repair laptop chargers and you were very informative. I just replace the output cord after opening the case. I mostly deal with original genuine chargers but after opening a few imitation or "replacement" chargers I noticed that most genuine have a breaker instead of a glass fuse, which is why I tell my customers to go buy or repair only original chargers.
    The ripple effect is what I am going to tell my customers about too, thanks for the pictures.

    • Jestine Yong

      October 24, 2012 at 8:43 pm

      Hi Lex,

      Thanks for the info and special thanks to Beh for providing the article.


  4. samuel

    November 4, 2012 at 8:54 am

    its really nice to know about the immitation charger, many thanks sir jestine

  5. Vibert

    December 31, 2012 at 7:58 pm

    thank you for this information. And, it is good to show the differrnce between the two DC voltages. However you should have used the dc coupling of the scope to better display the dc  level as from 0v to 6v or whatever. The straight line sweep shows a small negative or no voltage at all. Just thinking.


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