Understanding Amps

Discussion in 'General Electronics Chat' started by Edison, Apr 13, 2005.

  1. Edison

    Thread Starter Member

    Apr 13, 2005
    10
    0
    Can someone PLease help me to understand Volts and Amps.. In SIMPLE terms. Ok I can understand how Volts is the 'pressure' and amps are the flow..or current..Right so far?.. But I dont understand how one increases but not the other or vice versa. You can have a wind generator producing 48 volts but only one amp.. or one producing 48 volts and ten amps.. This is what I'm not getting.Or if the wind picks up first one goes from 48 to 56 volts but still only one amp How is this possible?I'm obviously missing something, is there a rulefor any of this? All comments are welcome.
     
  2. David Bridgen

    Senior Member

    Feb 10, 2005
    278
    0


    The generator will be able to produce only 1 amp because it is designed that way.

    Suppose you connect a 48 ohm load to it. At 48 volts there will be a current of 1 amp.

    Now increase the speed. The voltage can't rise to 56 because that would mean a current of 1.17 amps.

    If it can deliver 1 amp at 56 volts then that will be through a 56 ohm load.
     
  3. Brandon

    Senior Member

    Dec 14, 2004
    306
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    The rule is V=IR. Thats it.

    In most circumstances, you only have control over 1 of those values. 1 of them will be constant and the other will be your output basically. If you remember back from basic algebra, electricity is just the equasion for a line. y=mx. But since in MOST applications you will have control over the voltage, you will have I=V/R. R is most likley going to be constant since when you have resistance in a system or on a part, it doesn't change under normal operation and you solve for your current.

    Motors are a little different than you typical v=ir formula. Their magnetic coils have a different equasion set to describe their actions. These coils have a current maximum because of the number of loops in a magnet winding, the size of the core used in the windings, etc. Its a hardware limitation.

    Like each type of engineering, the situations you will be designing for will be very different and have different assumptions and limitations.
     
  4. Firestorm

    Senior Member

    Jan 24, 2005
    353
    0
    Hey edison,
    Basically u have the understanding of each 1's definiton.
    What you are confused at is what is proportional to on another.
    A volts are proportional with your current and resistance. Think of it this way.

    Say you have a balloon and you squeeze it in the middle. 1 side is our volts and the other is your amps. To get more volts you sqeeze farther down the balloon. To bump up your generator to 50+ volts you would have to add more air. This air can act as your load. The more resistance you have the greater current or volts will be needed to sustain the other 1. Does this make sense? Feel free to ask more questions...thx l8er

    -fire
     
  5. Edison

    Thread Starter Member

    Apr 13, 2005
    10
    0
    Ok, It might be slowly sinking in here, So Youre saying at 48 volts to increase amps I need more resistance, so if I add more resistance wont the volts go up accordingly?..What have I gained?and at what point is the proper balance if there is one?..Wire capability?..or generator capabilty?I'm still in the mindset that as volts go up..so should amps.
     
  6. Firestorm

    Senior Member

    Jan 24, 2005
    353
    0
    yes, as voltage goes up so do the amps. What we have been explaning in the generator example u used is how to maintain the sam # of amps. Amps will go up unless a bigger load(resistance) is applied. Hope this helps...thx l8er

    -fire
     
  7. Brandon

    Senior Member

    Dec 14, 2004
    306
    0
    I almost want to say your concentrating on stuff that really doesn't matter, but I know how it feels where there is a concept that is just eluding you.

    When thinking about power generation is better to think about it in terms of power and not in terms of voltage and amperage especially since you can have a millions combinations of volts and amps and come up with the same amount of power being delivered.

    Why would a windmill put out a higher voltage when the winder is faster? Because mother nature is putting more power into the system. Just like if the sun was focused onto a solar panel (typically they are 100W ~12v ~8amps) you may get a 5-20 watt power increase on the panel and it would either cause the voltage to rise, or the current to rise, or both to rise a little bit depending upon what the panel was connected to.

    V=IR is a relationship only. It describes the interaction between Electromotive Force (V), Flow of Electric Charge (I) and Resistance ®.

    If you want to turn the relationship into a definition you can say,

    The electric charge which flows (I) through a conducting medium when subjected to an Electomotive Force (V) is proportional to the Conductance (1/R) of the Medium.
    (I=V/R)
     
  8. Firestorm

    Senior Member

    Jan 24, 2005
    353
    0
    Yes, dont really concentrate on these basic terms to long. The more you apply them the better they will be understood. Try looking at some basic circuits and try to figure out the missing value given the other 2. Good luck and questions only make us smarter! :)

    -fire
     
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