Lesson plan (Ebook? Video? Both?) and the importance of understanding units

Discussion in 'General Electronics Chat' started by Tired guy, Feb 5, 2015.

  1. Tired guy

    Thread Starter New Member

    Apr 17, 2012
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    0
    So... I've recently started learning from the E-Book, and suddenly I ran into chapter 2 in volume 1...
    There's an explanation of what Voltage is using joules and newtons. I've gone over it a few times, looked through wikipedia, downloaded a physics book...

    Doesn't seem like something I can wrap my head around easily.

    I'm already embarrassed enough as it is by how slowly I'm moving along, and right now I don't want to have to stop and understand force, newtons and joules.

    How important is it for me to understand joules and newtons to be able finish the E-books and understand the basics enough to understand what's going on when I see a simple schematic?

    Also, I just happened (by chance) to notice there are also videos. Is there anything there that isn't in the E-book?

    Thank you very much :)
     
  2. tshuck

    Well-Known Member

    Oct 18, 2012
    3,531
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    Plenty...
    Maybe not on the surface.

    Knowing what they are will help put some things into perspective, but shouldn't affect your understanding of, say, an op amp.

    If you want the whole picture, yes. If you want a working knowledge, perhaps not.
     
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  3. sirch2

    Well-Known Member

    Jan 21, 2013
    1,008
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    For reading a simple schematic you don't need that level of detail
     
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  4. Tired guy

    Thread Starter New Member

    Apr 17, 2012
    11
    0
    Ooh... damn. Well, I'll take a step back and review these

    Excellent! Thank you. I'm definitely going to get back to that (In the more general scope of physics, not just electricity and electronics, but that's a separate matter as far as I'm concerned.
     
  5. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    7,388
    1,605
    The more you know the more you can know.

    Force may not come up too much in electronics until you have a motor or some actuator thqat needs to push something.

    Energy is a bit more needful as power is energy for a given time. For example, if your light bulb is 100 watts it is using 100 joules every second. Knowing that can be helpful is analysis when you need to calculate some parameter from seemingly incomplete information.

    "Ohm's law" describes so much of what happens you can get far knowing just that relationship. Ohm's law cares not about energy or force, so if you find it these things too confusing it is fine if you just note it for now and move on.
     
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  6. crutschow

    Expert

    Mar 14, 2008
    13,013
    3,233
    A few basics:

    A Volt is a unit of electrical potential or electromotive force (EMF).

    A Joule is a unit of energy, independent of any time.

    An Ampere is 1 coulomb of charge being transferred in 1 second (C/s).

    A Watt is energy per unit time or Joules per second.
    In a DC circuit or in an AC circuit with a resistive load, Watts equals Volts times Amperes (i.e. one volt drop times one ampere of current is one Watt).

    Note that mains energy is often given as watt-hours (which is a made-up unit that is more understandable to the customer). One watt-hour equals 1W * 3600 sec = 3600 Joules.
     
  7. MrChips

    Moderator

    Oct 2, 2009
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    Dimensional analysis is important in science and engineering and it is taught in first year of college and university.
    It means that when you use an equation or formula, check to make sure that the units on the left hand side of the equal sign and those on the right hand side are the same.

    In electricity and electronics you do not have to worry about newtons and maybe not so much joules but pay attention to volts, amps, ohms, watts, hours etc.

    For example,

    power (watts) = volts x amps = volts x volts /ohms = amps x amps x ohms
    energy (watts x hours) = volts x amps x hours

    So make sure the two sides of the equation are balanced.

    For example, power is NOT equal to energy.
     
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