USB powers up to the tune of 100W, new spec in the works

By Julio Franco
Aug 11, 2011
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  1. petert

    petert Newcomer, in training Posts: 17

    The main danger for electrocution are the high voltages and not the high currents. There are people that can feel the shock of an applied voltage of as little as 24 V (also there are some people that can't feel the shock even at 220 V due to their physiological nature). I guess that the voltages should never exceed the 19 V value (which is required by some laptops to be charged) and to stay on the safe side.
  2. Petert - I would rather get hit by a high voltage than a high current, example I would rather get hit by a 10,000 volt taser than grab both terminals on a 12 volt car battery....
  3. lol... I would rather touch a 12volt car battery myself. Given that the body has a resistance of kOhms, nothing would happen.

    Back to the books champ
  4. jobeard

    jobeard TS Ambassador Posts: 13,285   +281

    no one has mentioned that cable compatibility means this design will attempt to put
    100w thru 22 (or was it 24) gauge wire - - :wave: brain dead on arrival fellas!

    this AWG table shows
    that 22 guage can only handle 0.92 amps. With max current per USB connection at
    500ma, that's 6 watts (@12v). To get to 100W @12v, you need to deliver 8.3A and you get to kiss the 22guage cable goodbye.

    So as today is not April 1st and assuming that figures don't lie and the specification intends to actually deliver a product,
    we need to await that delivery and then evaluate the product as delivered.

    @Guest: The fine guys and gals that participate here have backgrounds that include actual work experience in far and highly varied fields,
    including Electrical Engineering. Sit back and enjoy the group. I might be a bold step on your part to actually become a member rather than continuing to harp under the anonymity cloaking of guest. No one will notice and you get to start with a clean slate :)

    If I had the choice of options, I would disable all posting by guests, not just this specific but on general principle.
  5. SNGX1275

    SNGX1275 TS Forces Special Posts: 12,419   +281

    Well not in those specific terms, but DBZ and red had a few posts with that concept.
  6. Burty117

    Burty117 TechSpot Chancellor Posts: 2,470   +299

    Is it me or are all the guest posts in this thread complete rubbish?

    you can have 14,000 volts sent through your body as long as the current is pretty much non existant.
    you cannot have 24v through your body if the current is high as it will litterally cook your insides.

    Why is that so hard to grasp? And before anyone goes "you cannot have 14,000 volts sent through your body" yes you can, I can't quite remember where it was but back at school years ago we went on a science school trip and a girl in my class was chosen to come up on stage when they were doing a presentation, they made her hold these pieces of metal and then they wound some kind of device, her hair went a bit freezy and was xtremely attracted to baloons but appart from that she didn't even realise that 14,000v was travelling through her body, and the reason it all worked was because the current was pretty much not there!
  7. jobeard

    jobeard TS Ambassador Posts: 13,285   +281

    Voltage doesn't go thru your body, current does. That's why a taser is not (normally) leathal.
    When working on a car, have you ever been shocked by a bad spark plug cable?
    That can be upwards of 20kv, but the current is minuscule.

    Fatal shocks are as little as 5ma; see this wiki

    @SNGX1275; with some 30+ posts, I didn't see those comments :eek:
  8. @ guest under my post of "Petert - I would rather get hit by a high voltage than a high current, example I would rather get hit by a 10,000 volt taser than grab both terminals on a 12 volt car battery...."

    I have a background in electronics an will swear by my statement, and I will back it up with a rather graphic mental image of a less than careful co-worker that managed to accidentally complete the circuit on a car battery by means of an arm, and have his wedding ring fused into his skin. Give me a fork and a mains socket any day!

    Oh and registered members calling all guest posts pointless, wrong and useless; superiority complex much? Stick it up your arses and your fake forum names.
  9. jobeard

    jobeard TS Ambassador Posts: 13,285   +281

    From a 12v source 5ma IS possible e=ir ; e/i = ? 12/0.005 = 2400 ohms.

    entirely possible as the conductivity of skin varies inversely to wetness
    (ie the wetter you get, the lower the resistance )

    PS: jobeard is real; J. O. Beard (if you read the signature).
    Using real names reminds one to be carefull with what you say online.

    Nom de plume and ghost writers (imo) denigrate themselves due to some
    ulterior motive or some political necessity. As the kids are starting to say "MAN UP"
  10. dividebyzero

    dividebyzero trainee n00b Posts: 4,783   +639

    Now, now...don't be going all butthurt on us.

    While there may be some members here who pin every Guest post with the stupid tag, I think you'll find that the prevailing sentiment here (much like the ever diminishing number of other sites that allow non-registration posting) is that for the occasional reasoned statement, it really isn't worth wading through the dross of "Guests" in the form of company shills, PR shills, drive-by kiddies, rampant fanboys, forum members from other sites spamming the threads, and generic internet trolls.
    Think that's an overstatement ? Be my Guest and use the search function to look for posts using the keywords (in alphabetical order) AMD, Apple, ATI, Intel, Microsoft, Nvidia, Sony, Windows etc... and look at the quality of the Guest posting...then ask yourself whether you think it was worthwhile spending the few minutes of your life reading them.
  11. spydercanopus

    spydercanopus TechSpot Guru Posts: 802   +87

    Someone get Bill Nye in here..
     
  12. dividebyzero

    dividebyzero trainee n00b Posts: 4,783   +639

    Van de Graaff generator
  13. I take my, as devidebyzero so eloquently put "butthurt" comment back.

    After taking a scan at the comments I can completely agree 90% of the guest comments are moronic. I can understand why registered users dismiss these posts almost immediately, but consider this, people fly by these websites so often as there are so many, and want a small amount of instant input without going through the trouble of signing up.

    Would you like to sign up to every single website that you visit? No I hear you say.

    For the most part it seems registered users are the ones getting "butthurt" over guests comments, most of which are obviously "trolls"
  14. I left on a fairly long trip down the interstate and when I went to plug in the GPS an hour down the road it turns out one of the children had put a coin in the cigarette lighter/power connector. Had to ask for directions.
  15. I completely understand what registered users are talking about.

    anyways my input is this. I dont know ANYTHING about electricity other then how manny watts are needed for computer components, so i will not argue with anyone.

    my point is this = if they say it can be done im sure it can be, as for limitations im sure they know what they are and the problems that would arise if they dont take precautions.

    all in all i say everyone stop acting like children fighting over pitiful things with people that you wont ever see, and mean nothing to you or your life. Even if you do win the debate it doesnt mean anything. you get some satisfaction yes.

    but at the end of the day your input means nothing as USB will work out the bugs and issues and finally release the update.... just stop fighting and making a big deal out of nothing. Just be damn happy that we have a new update coming to our computers! -____-

    1-4 people will die yearly from shock. and no one will be able to over current their motherboard..
    USB has done very well so far, doubt they would be morons and not let concerns like all of yours fall on def ears....


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