Q: How is it that the transformer isn't burning up?

Discussion in 'General Electronics Chat' started by DkEnrgyFrk, Sep 15, 2012.

  1. DkEnrgyFrk

    Thread Starter New Member

    Feb 15, 2010
    I thought that coils were used in transformers to affect other coils nearby via an electromagnetic field. That this is done in order to transform the power up or down. Like low voltage to high and vice versa. Also, same regard with current.
    So how is it that a single coil(the transformer coil) can do what it is doing in this video? How can it be upscaling the current that is directly attached to it? This isn't occuring via induction, right? There's physical contact!


    How can it not be burned up just as is the items attached to it's wiring? Isn't the wires coming out of the transformer connected in series with it? Why would the current be any different at the exterior point than at any other point in the wire along the coil(inside the transformer)?
    Why doesn't hooking up the wires(coil) of this single transformer directly to a power source cause an explosion? There isn't any resistance to infinite current since there isn't a resistor attached to an end of the circuit, right?

    It's just so confusing seeing one coil do what it's doing. I thought you needed two coils for transformers to work. That one coil would have a greater number of turns and the other lesser depending on which way you wanted to power to scale....
  2. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    It has to do with how 'power' scales vs. resistance.

    one is a squared factor and the other is simply a ratio.

    So the smaller wires offer a larger resistance to the current, but the currents heating effect increases much faster than the resistance can decrease current flow.

    Resistance decreases current flow directly as a simple ratio(fraction)

    I = V / R

    Heating(power) increases as a squared value of current times resistance.

    P = I(squared) * R

    The inductance has no affect on the 'heating power' of current. Only the level of resistance and amount of current are used to calculate it.
    Last edited: Sep 15, 2012
  3. shortbus

    AAC Fanatic!

    Sep 30, 2009
    The video without an explanation of what he was trying to show is just kind of dumb. the transformer is just a high current step down transformer. The metal items attached to the secondary where steel and that makes them high resistance. The high resistance makes them heat up until they melt. When they melt there is no longer a circuit, so the electric stops flowing.

    I guess I don't know what your really asking. It is a transformer and the pieces are being put to the low voltage secondary. You just can't see the primary wires.
  4. DkEnrgyFrk

    Thread Starter New Member

    Feb 15, 2010
    You guessed what I was asking. I don't see two coils. So you are saying that there is a primary and secondary coil in that transformer?
    So this secondary side IS dropping the voltage and upping the current.
    I guess I need to take a look at the innards of one of those.
  5. MikeML

    AAC Fanatic!

    Oct 2, 2009
  6. praondevou

    AAC Fanatic!

    Jul 9, 2011
    Well you can see the black cable on the left upper side. This goes to the primary coil.