Download Provisional Patent Application of

Electricity and Magnetism in Wires
This video from M.I.T. demonstrates the effect of electrical current on two parallel wires:
http://www.youtube.com/watch?v=43AeuDvWc0k&feature=related&app=desktop
To avoid this situation, we try to separate wires as far as possible (within the meager space behind our
equipment). When wires cross, we persevere to make them intersect at 90°. Oftentimes this is difficult
and sometimes we simply can’t. We all share this frustration. As a hobbyist, I knew the need for
keeping wires away from each other. As an architect, I understood the science and sought a design
which will provide separation between wires.
Science
We know that when current is running through a wire, magnetic fields are generated. For example, if a
current of 20 amperes is running through a #12 AWG wire, the magnetic fields at different distances
from the wire are the following:
R
B
(inch)
(Gauss)
*0.04
¼
½
1
2
3
4
5
6
12
39.00
6.25
3.15
1.57
0.79
0.52
0.39
0.32
0.26
0.13
Where R is the radial distance and B is the magnetic field strength
*Radial distance of #12 AWG wire
To those interested, you can read about it here:
http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/biosav.html
http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/magcur.html
So what do those Gauss numbers mean? Well, for comparison, look at this table:
Gauss
Earth at its surface
0.31-0.58
Average refrigerator magnet 50
MIR machine
600-70,000
Source: http://en.wikipedia.org/wiki/Gauss_(unit)
Obviously, letting two current-carrying wires touch each other is never a good idea…similar to sticking
a magnet in there. At least, a 4” separation should be provided, which magnetic field strength
approximates that generated by planet Earth.
Now that we understand the reason why we should not run wires parallel and close to each other, can we
scientifically prove that it is worthwhile to cross them at 90°?
1/4
Forces on a Wire
When a current-carrying wire is placed in an external magnetic field, each of the moving charges in the
wire, which comprise the current, experiences the Lorentz force, the force due to that external magnetic
field. A variation on this basic formula is the Laplace force, which is:
F = Bil(sinθ)
Where,
F
Laplace force on a current-carrying wire, joules
B
external magnetic field where said wire is placed, Gauss
i
electric current running in said wire, amperes
l
length of said wire, meter
θ
angle between said wire and the external magnetic field B
Source:
http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/magfor.html
http://en.wikipedia.org/wiki/Laplace_force#Force_on_a_current-carrying_wire
This law obeys Fleming’s Left Hand Rule, where your left index finger points in the direction of the
magnetic field “B”, your middle finger points in the direction of the electrical current “i”, and your
extended thumb points in the direction of the force “F” exerted by the external field.
To those who are graphically oriented like me, see this drawing:
From: http://www.magnet.fsu.edu/education/tutorials/java/handrules/index.html
2/4
Two Wires Perpendicular to Each Other
Shown in Figure 1a above are two wires (W1 and W2) which are perpendicular to each other, where
current i1 is parallel to magnetic field B2, thus making angle θ in the Laplace equation equal to 0°.
Because sine 0° is zero, there will be no Laplace force F2 acting on wire W1. And vice versa, there will
be no force F1 acting on wire W2. On the other hand, when two wires are parallel to each other, where
current i1 is perpendicular to the magnetic field B2 (see Figure 1b), the Laplace force F2 will be at its
maximum because θ is 90° (i.e., sine 90°=1). Remember that www.youtube.com video from MIT?
Design
Douglas Engelbart, in describing his patent for the computer mouse said, “The invention was just
putting together things that we’ve already known.”
Like Engelbart, I sought to design with what we already know as science, but guided by my design
sensibility. I like architect Tadao Ando and his primal platonic solids. I want it so basic in form that it
cannot be simplified further. Simply: to align and lift wires from each other. What can be simpler than
yet another wire working against gravity? And so I persevered in my garage…modifying each drawing
as I pounded each prototype into shape.
3/4
To the left is what I hammered and bent in my garage.
This is how I envisioned it to work.
I applied and have been granted provisionary patent, my very first!
[email protected]
4/4