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A Practical Guide to 'Free-Energy' Devices

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It appears from equation (4) that the e.m.f. depends on the forward velocity with which the test charge<br />

moves along the path C. This, however, is not the case. If V and dl in equation (4) have the same<br />

direction, then their associated scalar product is zero. So, only the component of V which is not aligned<br />

with dl (that is, with θ = 0), can contribute <strong>to</strong> the e.m.f. This component has value only if the differential<br />

path length dl has a sideways motion. So, V in equation (4), represents the sideways motion of dl, if there<br />

is any. The fields E and B in equation (4) could well be represented as functions of time as well as<br />

functions of the space co-ordinates. In addition, the velocity V of each differential path length dl, may<br />

vary with time. However, equation (4) correctly expresses the e.m.f. or voltage drop along path C as a<br />

function of time. That component of the e.m.f. consisting of the line integral V x B is the motional E-field<br />

since it has value only when path C is ,moving through a magnetic field, traversing lines of magnetic flux.<br />

For stationary paths, there is no motional E-field and the voltage drop is simply the integral of the electric<br />

field "E". <strong>Devices</strong> which separate charges, generate e.m.f.s and a familiar example of this is a battery<br />

which utilises chemical forces <strong>to</strong> separate charge. Other examples include the heating of a<br />

thermocouple, exposure of a pho<strong>to</strong>voltaic cell <strong>to</strong> incident light or the rubbing <strong>to</strong>gether of different<br />

material <strong>to</strong> produce electrostatic charge separation. Electric fields are also produced by time-varying<br />

magnetic fields. This principle is already exploited extensively in the production of electrical power by<br />

the utility companies.<br />

The line integral of electric field intensity "E" around any closed path "C" equals -dφ/dt where φ<br />

represents the magnetic flux over any surface "S" having the closed path "C" as it's con<strong>to</strong>ur. The<br />

positive side of the surface S and the direction of the line integral around con<strong>to</strong>ur C, are related by the<br />

right-hand rule (the curled fingers are oriented so as <strong>to</strong> point around the loop in the direction of<br />

integration and the extended thumb points out the positive side of the surface S). The magnetic flux φ is<br />

the surface integral of magnetic flux density "B" as shown here:<br />

In Equation (5), the vec<strong>to</strong>r differential surface "ds" has an area of ds and in direction, it is perpendicular <strong>to</strong><br />

the plane of ds, projecting out of the positive side of that surface. The partial time derivative of φ is<br />

defined as:<br />

This is referred <strong>to</strong> as the magnetic current through surface S. For a moving surface S, the limits of the<br />

surface integral in equation (6) are functions of time, but the equation still applies. It is important <strong>to</strong><br />

clarify at this point, that when we evaluate the value of dφ/dt over a surface which is moving in proximity<br />

<strong>to</strong> magnetic field activity, we treat the surface as though it were stationary for the instant under<br />

consideration. The partial time derivative of φ, is the time rate of change of flux through surface S, due<br />

only <strong>to</strong> the changing magnetic field density B. Any increase of φ due <strong>to</strong> the motion of the surface in the<br />

B-field, is not included in that calculation.<br />

Continuing this discussion leads us <strong>to</strong> note that an electric field must be present in any region containing<br />

a time-varying magnetic field. This is shown by the following equation:<br />

In this equation, φ is the magnetic flux in webers out of the positive side of any surface having path C as<br />

its con<strong>to</strong>ur. Combining equations (7) and (4), we are able <strong>to</strong> calculate the e.m.f. about a closed path C as<br />

shown here:<br />

A - 1206

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