3.7V 2000mA power adapter

Discussion in 'General Electronics Chat' started by kevindd992002, Oct 30, 2012.

  1. kevindd992002

    Thread Starter Member

    Nov 23, 2010
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    I'm using a zBoost YX-520I cellphone signal booster and suddenly its power supply is blinking and does not power the device. In my experience, blinking power adapters indicate a short. The power adapter has a solid green when NOT connected to the device but as soon as it is connected to the device, it blinks. This can only mean that it's either shorted or its output current rating is reached (overcurrent). I tried using a 4.5V power supply and it powered up the device but I know that that is not good practice (I did that just to test). That simply means that the power supply of the device is broken.

    I'm having a hard time looking for a power adapter with output rating of 3.7V 2000mA. Can anyone help me on this? Oh and btw, how do I know if this adapter is linear or switching?

    Thanks for the help.

    EDIT: Today, I brought the 3.7V power supply to work and tested it with a DC Current Source as my load. I swept the current load from 0 to 2000mA with 10mA steps. With the first sweep, the output voltage of the power supply dropped to 0 at around 330mA and it started to blink (as I expected). With the second sweep, it passed 330mA and dropped out at around 750mA which seems to be an improvement of some kind. With the third sweep, the power supply was able to handle the full 0 to 2000mA range without any problems (no blinking - solid green light). This observation shocked me and led me wondering what made the power supply work. What do you think happened? Was there some kind of "jump start" that fixed the power supply?

    Oh by the way, the power supply is as small as the old Nokia cellphone chargers and are very light. Am I sure that this is a switching power supply then?

    Thanks.

    EDIT: False positive! After writing my response here, I tried sweeping current load again from the power supply and it started to blink at 330mA again. Does this indicate a faulty power supply already?
     
  2. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    4,771
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    Well my first call would be to zBoost customer service.. Tell them the problem and they might just send you a new power supply for free or at least tell you where to buy one.

    Is there a part number or company or whatever on the adapter?
    You sure its 3.7V 2000mA?
    Post a pic of the adapter (label showing)
     
  3. kevindd992002

    Thread Starter Member

    Nov 23, 2010
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    I actually already told zBoost my problem and they sent me a whole unit (all complete in box) for free. So right now, I have two units with the old one not used because of a faulty power supply. Instead of not doing anything with it, I still need to look for a power supply for the old one so that I can use it in my other house.

    Yes Sir, I am 101% sure that it's 3.7V 2000mA. See for yourself in this pic:

    [​IMG]

    And as I've mentioned, I've already tested this with a DC source to source current from the power supply. The output voltage was around 3.8V (as expected, to compensate for voltage drop due to loading effect).

    Any other way to look for this power supply without asking directly from zBoost?
     
  4. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
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  5. kevindd992002

    Thread Starter Member

    Nov 23, 2010
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  6. kevindd992002

    Thread Starter Member

    Nov 23, 2010
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    They are not replying, as I've expected with these chinese companies.
     
  7. Audioguru

    New Member

    Dec 20, 2007
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    3.7V is the nominal voltage for a load powered from a single rechargeable Lithium cell.
    Maybe the "booster" is designed to power the product when the battery is fully charged to 4.2V so the battery does not draw charging current. Then when the battery has run down it draws a very high current since it is charging from the 3.7V "booster".
     
  8. kevindd992002

    Thread Starter Member

    Nov 23, 2010
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    But the booster doesn't have any battery. It is DC power supply operated as similar to other electronic devices.
     
  9. kevindd992002

    Thread Starter Member

    Nov 23, 2010
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    BUMP! 10char.
     
  10. SgtWookie

    Expert

    Jul 17, 2007
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  11. kevindd992002

    Thread Starter Member

    Nov 23, 2010
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    Hmmm, I thought you need exactly 3.7V?
     
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