Berkeley CSUA MOTD:Entry 10965
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2019/08/21 [General] UID:1000 Activity:popular
8/21    

2003/11/6 [Science/Electric] UID:10965 Activity:nil
11/6    For AC adapters, if something says it needs 4.5V 300mA, is it all right
        to use something higher-rated, like 4.5V 500mA? Why or why not? Thanks.
        \_ The neutron flux can break down the gamma field.
           Get some ball bearings.
           \_ Good advice.  Also, don't cross the streams or there will be a
              total protonic reversal.
              \_ and don't forget that in the interstitial space-time vortex,
                 E=mc^3, not mc^2.
                 \_ Only one other person got the joke :-(
                 \_ It's ok if it goes through the deflector shields after a
                    biphase zeta wave realignment of .856 megaparticles.
                    \_ And dial down the induction manifold to -3i to
                       delay the capacitance of the electrostatic relay
                       inhibitors.
                       \_ Captain!  No don't!  You forgot about the tachyon
                          wave emitters!  We'll fry the transdiode reverse
                          couplers!
                          \_ Don't worry, this is all taken care of by
                             the Heisenberg Compensator.
                             \_ As long you don't forget to reverse the
                                polarity of the phased conjugate graviton
                                beams you'll be okay.
              \_ Important safety tip!
        \_ yes it is ok, though dont go *too* far overrated.  And, of course,
           make sure you're matching DC/AC, and polarity of plugs.
           \_ The reason why it is OK is because the current is just the
              maximum current the adapter can put out.  If your adapter can
              put out 2A, and you need 1mA, nothing will blow up.
        \_ I think these guys are screwing with you.  I once plugged an AC
           adapter for a phone into my Speak 'n' Read and that shit blowed up.
           I think the wattage on the adapter is what it puts out, not what it's
           capable of handling.
           \_ Unless you can tell me the voltage of the adapter and the voltage
              your Speak 'n' Read needs, it just sounds like you mismatched
              voltages, which will obviously be bad.
              \_ Yeah, I was probably 6 or 7 years old at the time.
        \_ Current = Voltage / Impedance.  For a 120V input the max current
           an adapter can put out is determined by it's impedance.  When you
           hook up something to an adapter, you get a more complicated circuit.
           The current the adapter can put out is the limit before its internal
           resistance becomes a factor.  When you need way less than that, the
           resistance of your device is the limiting factor.  It's sort of like
           how it's OK to run a garden hose off of a huge pipe (high current)
           just as long as the pressure isn't too high (high voltage).
           \_ it's also worth pointing out that the consequences of doing
              screwy things with the power depend strongly on how well-designed
              the device is.  A good designer should *assume* that the user will
              do horrible things to the power, and plan accordingly so no
              damage is done unless you do something *really* terrible.
              On the other hand, there are more horse's asses in the world
              then there are horses.
2019/08/21 [General] UID:1000 Activity:popular
8/21    

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