Help needed with parallel power

Discussion in 'General Electronics Chat' started by Biojack, Nov 16, 2011.

  1. Biojack

    Thread Starter New Member

    Nov 16, 2011
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    Hi, I am far from being and expert in electronics and could use your help. Last time I played with electronics was in HighSchool. My question: Could someone easily wire two 19.5V 4.62A laptop power adaptor (Dell) in parallel to replace an Asus 19.5V 150W power adaptor? I just came back from a trip and realized I left my computer power adapter behind. Having it shipped to me would take a week if it is found and I have called every local stores I could think of and nobody has a 150W laptop power adapter. Tried to order from Asus and it is back ordered. I have urgent work to do, including sending my resume since my job was cut in a company restructuring. Since I cannot get my hands on a power adaptor that supplies the 150W I started looking around and the best I came up so far is these two old dell adapters. Frying my computer would be the worse so I'm really nervous about trying to fix this problems myself. I found your forum while searching the web for possible ideas. Please Let me know of this is something this group could help me with.

    Regards,
    Jack
     
  2. cube01

    New Member

    Mar 10, 2011
    16
    1
    4.26A is not a measure of wattage; it is a measure of current.
    How many watts (W) do the Dell adapters list? (Usually Dell adapaters are 60W and and 90W)... Though I assume that since you are saying 4.26A is listed, that you are using the 90w adapter.
    How many Amps (A) does the Asus adapter list?

    Either way, as long as you are supplying the correct Voltage (V), you shouldn't have a problem - A laptop will only draw as much current as its internal resistance allows based on the voltage supplied, thus only using as much power (watts) as it needs (given the correct input voltage.)

    In other words - you should be Ok using a single Dell adapter to power your Asus laptop, as long as the output voltage of the adapters is the same.
     
  3. Biojack

    Thread Starter New Member

    Nov 16, 2011
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    Thank you for the reply. Should I be concerned that the dell adaptor is rated 90W if my Asus laptop requires 150W? I do know that the computer use lots of power since the 150W asus adapter gets really hot when I'm working on images. That's why I was asking if using the two dell adapters in parallel might be better/safer. Thanks!
     
  4. kubeek

    AAC Fanatic!

    Sep 20, 2005
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    If you leave your laptop to charge overnight when off, then run it with full battery on AC you should be ok. The most power is used when charging a flat battery and running the notebook on full power simultaneously. Used separately it should work, worst that can happen is the adaptors overcurrent or thermal protection kicking in and switching the adaptor off.
     
  5. MrChips

    Moderator

    Oct 2, 2009
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    It would not be a good idea to parallel the two adapters. Look at the bottom side of your ASUS and there should be a label with the power requirements, e.g. 19V 3A or something like that. Get an adapter with the same voltage rating and same current or higher rating. Make sure that the polarity of the connector matches the requirements of the ASUS.

    As cube01 suggests, the single Dell 19.5V 4.6A adapter should be fine. Again, double check that the polarity is correct before connecting.
     
  6. Biojack

    Thread Starter New Member

    Nov 16, 2011
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    Under the laptop it says 19.5V and 7.7amp.
     
  7. Biojack

    Thread Starter New Member

    Nov 16, 2011
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    None of the local stores have power adaptor that can provide more than 90W. That's why I have been looking at other options while I wait for mine to be delivered. That will be faster than ordering one from eBay since I'm in Canada.
     
  8. MrChips

    Moderator

    Oct 2, 2009
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  9. Biojack

    Thread Starter New Member

    Nov 16, 2011
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    Thanks I appreciate you looking into this.., I'm not looking to buy one online, I can have mine shipped for cheaper/faster. I was just looking for a way to get on my computer today and work for a few hours on it. I looked at factory direct and delivery would be dec 3.... I can get mine shipped ground to arrive next week or air, but that's almost $100. I guess i'll try the single dell adapter after charging for a few hours but I'm afraid my laptop will kill it. It uses a lot of power and the new battery only last about 1.5 hour. I'm open to any other ideas than the parallel dell adapters. Thanks for letting me know that this wasn't a good idea.
     
  10. kubeek

    AAC Fanatic!

    Sep 20, 2005
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    If you need a workhorse, get a PC. I personally don´t see any point in having a quadcore notbook that consumes 100W.

    Which reminds me, how big is your battery? I mean in Wh.
    Lets say it is 60Wh, then if the battery lasts 1,5h, the laptop draws 60/1,5=40W.
     
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