07-10-2009, 08:22 AM
This hasn't been mention...so...
voltage is the ability of electricity to jump...analogous to the height of a waterfall. If you've ever seen a bed sheet or towel spark...that is a buildup of thousands of volts but spark has very little amperage.
Amperage is the quantity of charge moving...analogous to the size of a river. (note that the word "current" is used both to describe the flow of electricity and the flow of water)
Because amperage is the quantity...it is what requires larger wires...not the voltage. If you think about this, you'll realize that wiring for DCC involves house wiring even though only 1/10th the power is being used. That is because the amperage can be the same...even though the voltage is 1/10th the size.
The square of the current multiplied by the resistance is how much heat will be given off at any point in a circuit. Copper is great because of its low resistance...and hence it can handle more current without getting fried than aluminum or steel. In the words of one of my former professors, we in the US have the luxury of using 110V instead of 220V due to our ability to use more copper in our homes. 220V has a greater ability to jump out and grab you...but doesn't need as large of wires (as much metal).
If you had a small enough saw, you could actually make the gaps in your rail so short that the electricity would jump despite the gap. Or, if you raise the voltage sufficiently, it would jump with your current gaps.
As a footnote...if you understand the fundamental equations for electricity, you also understand the fundamental equations for fluid mechanics and mass transfer...one of the cooler aspects of science!
voltage is the ability of electricity to jump...analogous to the height of a waterfall. If you've ever seen a bed sheet or towel spark...that is a buildup of thousands of volts but spark has very little amperage.
Amperage is the quantity of charge moving...analogous to the size of a river. (note that the word "current" is used both to describe the flow of electricity and the flow of water)
Because amperage is the quantity...it is what requires larger wires...not the voltage. If you think about this, you'll realize that wiring for DCC involves house wiring even though only 1/10th the power is being used. That is because the amperage can be the same...even though the voltage is 1/10th the size.
The square of the current multiplied by the resistance is how much heat will be given off at any point in a circuit. Copper is great because of its low resistance...and hence it can handle more current without getting fried than aluminum or steel. In the words of one of my former professors, we in the US have the luxury of using 110V instead of 220V due to our ability to use more copper in our homes. 220V has a greater ability to jump out and grab you...but doesn't need as large of wires (as much metal).
If you had a small enough saw, you could actually make the gaps in your rail so short that the electricity would jump despite the gap. Or, if you raise the voltage sufficiently, it would jump with your current gaps.
As a footnote...if you understand the fundamental equations for electricity, you also understand the fundamental equations for fluid mechanics and mass transfer...one of the cooler aspects of science!
Michael
My primary goal is a large Oahu Railway layout in On3
My secondary interests are modeling the Denver, South Park, & Pacific in On3 and NKP in HO
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My primary goal is a large Oahu Railway layout in On3
My secondary interests are modeling the Denver, South Park, & Pacific in On3 and NKP in HO
<!-- m --><a class="postlink" href="http://thesouthparkline.blogspot.com/">http://thesouthparkline.blogspot.com/</a><!-- m -->