Patent Publication Number: US-2020295677-A1

Title: Power Receiver Including Faraday Cage for Extracting Power from Electric Field Energy in the Earth

Description:
FIELD OF INVENTION 
     The present invention relates generally to renewable energy, and more particularly to methods and apparatus for extracting energy from subsurface electrical fields beneath the earth&#39;s surface. 
     BACKGROUND 
     It is hypothesized that there exists standing electromagnetic waves beneath the surface of the earth, which resonate within the range of the Schumann resonances. Schumann resonances are global electromagnetic resonances, generated by earth&#39;s geodynamo and excited by lightning discharges in the cavity formed by the Earth&#39;s surface and the ionosphere. The Schumann resonances occur between 3 Hz and 60 Hz, with distinct peaks at extremely low frequencies (ELF) around 7.83, 14.3, 20.8, 27.3, 33.8, 39, and 45 Hz. The earth&#39;s geodynamo and its generated and rotating magnetic field, and positive lightning, are two energy sources believed to sustain the ELF standing waves within the earth. Non-resonant electromagnetic waves generated by the earth&#39;s geodynamo in the frequency range of 0.1 to 200 Hz further enrich the energy levels of the standing Schumann resonance waves at points where the resonant and non-resonance waves intersect beneath the earth&#39;s surface. 
     The Background section of this document is provided to place embodiments of the present invention in technological and operational context, to assist those of skill in the art in understanding their scope and utility. Unless explicitly identified as such, no statement herein is admitted to be prior art merely by its inclusion in the Background section. 
     SUMMARY 
     The following presents a simplified summary of the disclosure in order to provide a basic understanding to those of skill in the art. This summary is not an extensive overview of the disclosure and is not intended to identify key/critical elements of embodiments of the invention or to delineate the scope of the invention. The sole purpose of this summary is to present some concepts disclosed herein in a simplified form as a prelude to the more detailed description that is presented later. 
     According to one or more embodiments described and claimed herein, a circuit is operative to extract electromagnetic wave energy from the ground via a resonant transformer in which resonance is triggered by electrical charge arcing across a spark gap. A center tap of the primary winding of the transformer is capacitively coupled to an electrode buried in the ground. In-rush current from the ground electrode is converted to a useful form (e.g., one- or three-phase 60 Hz AC) by a power conversion circuit connected to the secondary winding of the resonant transformer. The ground electrode of the capacitor coupling the grounded electrode to the center tap primary winding is the shield of a Faraday cage enclosing the resonant transformer, spark gap, and a high-voltage power supply exciting the spark gap. 
     One embodiment relates to a power receiver for extracting electromagnetic wave energy from the earth&#39;s electric field. The power receiver includes a resonant transformer having a centertapped primary winding and a secondary winding. A high voltage power supply is connected across the primary winding of the resonant transformer, and a pair of electrodes separated by a spark gap is interposed between the high voltage power supply and one side of the primary winding of the resonant transformer. The electrodes are configured to generate a spark when a voltage difference between the electrodes reaches a predetermined level. The power receiver also includes a first capacitor connected between the center tap of the primary winding of the resonant transformer and a ground terminal disposed below the surface of the earth; the first capacitor is operative to capacitively couple the primary winding centertap to ground. A power conversion circuit is connected to a secondary winding of the resonant transformer, and is operative to convert electrical current flowing from the grounded electrode to a desired form. The grounded terminal of the first capacitor comprises the shield of a Faraday cage enclosing the high voltage power supply, the electrode pair, and the resonant transformer, 
     Another embodiment relates to a method of receiving power from the earth. A grounding electrode is disposed below the surface of the earth. A high voltage power supply, a pair of spark gap electrodes, and a resonant transformer are disposed within a coupling capacitor that also functions as a Faraday cage. The shield of the Faraday cage is electrically connected to the grounded plate of the coupling capacitor. The grounding electrode is coupled to a center tap of a primary winding of the resonant transformer via the coupling capacitor. The primary winding of the resonant transformer is excited with a high voltage pulse generated by applying a high voltage across the spark gap electrodes, causing a spark, and coupling the high voltage pulse into the primary winding. AC power from a secondary winding of the resonant transformer is converted to a useful form. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. However, this invention should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. 
         FIG. 1  is a functional electrical schematic of a circuit for receiving electrical energy from the earth. 
         FIG. 2  is a sectional perspective view of a capacitor and Faraday cage. 
         FIG. 3  is a flow diagram of a method of receiving power from the earth. 
     
    
    
     DETAILED DESCRIPTION 
     For simplicity and illustrative purposes, the present invention is described by referring mainly to an exemplary embodiment thereof. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be readily apparent to one of ordinary skill in the art that the present invention may be practiced without limitation to these specific details. In this description, well known methods and structures have not been described in detail so as not to unnecessarily obscure the present invention. 
       FIG. 1  depicts a representative circuit for extracting useful electrical energy from the ground. A ground electrode  25  is disposed underground, and capacitively coupled to a resonant transformer  45  by a coupling capacitor  50 . The ground electrode may comprise a ⅝-inch×8-foot copper ground rod, such as the ERICA 615880UPC. The coupling capacitor  50  connects to a center tap of a primary winding  35  of the resonant transformer. A high voltage power supply is connected across the primary winding  35 , with a pair of electrodes  90  interposed between the power supply and one end of the primary winding  35 . A suitable high voltage power supply is a United Nuclear supply operative to generate 25 kV DC (open circuit), from 12 V inputs at 1.0 A. The electrodes  90  are spaced apart, and operative to generate a spark when the high voltage power supply creates a voltage difference between the electrodes of a predetermined level. A suitable spark gap electrode pair is the Information Unlimited SPARKOS ¼-inch×1-inch tungsten electrodes, 
     The spark generates a high voltage pulse into the primary winding  35 . In one embodiment, sparks are generated at a frequency of about 7.83 sparks per second and the duration of the sparks is approximately 10 microseconds. This pulse is operative to cause resonance in the transformer, in a frequency range of between about 0.1 and 200 Hz. In one embodiment, the resonant transformer has a Q factor of about 10 or greater. In one embodiment, the resonant transformer  45  has a resonance frequency of about 7.83 Hz, the fundamental Schumann resonance frequency. A suitable transformer is Allanson 1530 BPX 120R, having a primary of 120 V, 60 Hz, 450 VA and a secondary of 15 kV, 30 mA. In one embodiment, a neon sign transformer may be used in a step-down configuration, with the high voltage pulse applied to the secondary output from the primary coil. 
     The resonant transformer  45  includes a secondary winding  40 , which is connected to a full bridge rectifier  115 . A suitable rectifier is the HVP-16 Rectron Rectifier with a 750 mA, 16 kV max peak, comprising four diodes. Alternatively, a full bridge rectifier  115  may be constructed from diodes, the selection and configuration of which are well within the skill of those of ordinary skill in the art. A filter capacitor  120  connected across the output of the rectifier  115  removes unwanted frequency components from the DC current provided. A suitable capacitor  120  is a CDE 940C16VV1K-F 1 uF 1600 VDC. The filter capacitor may also be connected to the grounded electrode  25 . The rectified voltage across the filter capacitor  120  is input to a DC-DC power conversion unit to optimize the DC output of the rectifier  115  to various loads. 
     In one embodiment, the DC-DC power converter is a maximum power point tracking (MPPT) charge controller, such as a Tracer 4215 BN MPPT Solar Charge Controller, which is commonly used in solar power generating systems. As known in the art, an MPPT controller alters the voltage and current relationship of DC power by first converting the DC input to high frequency AC (e.g., 20-80 kHz), and then converting the AC back to a different DC voltage and current that is optimized to one or more loads. For example, the MPPT charge converter  125  may apply a small amount of energy to a battery  130  to charge the battery  130 , such as a 12 V, 7.0 A/H sealed lead acid battery, such as the ELB 1270A by Lithonia Lighting. The main loads to the MPPT  125  are the high voltage power supply, and an inverter  135 , which converts the DC current to an AC current with a desired voltage and frequency, e.g., 120 volts at 60 Hz, as well known in the art. 
     It is hypothesized that current transferred from the ground electrode  25  to the resonant transformer  45  is not carried by the cables as is conventional household current, but rather travels via “skin effect” on the surface of the conductors. As such, it is prone to generate “step leaders,” or the initial fingers of a plasma discharge, on and over cables and components. This presents an electrical shock hazard and is a source of power loss, lowering the system efficiency. Accordingly, as indicated by the dashed line in  FIG. 1 , the high voltage power supply, spark gap electrodes  90 , resonant transformer  45 , and coupling capacitor  50  are enclosed in a Faraday cage. In particular, according to one embodiment, the coupling capacitor  50  physically forms a Faraday cage, with the ground terminal of the coupling capacitor  50  forming the grounded shield of the Faraday cage. 
       FIG. 2  depicts a combination coupling capacitor  50  and Faraday cage. A dielectric cylinder  56 , such as a 1-foot section of SCH-40 6-inch PVC pipe, or other suitable material, is coated on the exterior by a conductive layer or plate  52  comprising a grounding plane, which is electrically connected to the grounding electrode  25 . A suitable exterior plate  52  material is Phifer 3030990 bronze screen (90% copper). The interior of the dielectric  56  is covered by a conductive layer or plate  54 , which is electrically connected to the center tap of the primary winding  35  of the resonant transformer  45 , which is physically disposed within the Faraday cage  50  but otherwise isolated from the interior plate  54 . A suitable interior plate  54  material is 10-mil copper sheet formed about and affixed to the dielectric cylinder  56 . Also disposed within the Faraday cage  50  are the high voltage power supply and spark gap electrodes  90 . 
     Although depicted in sectional perspective view in  FIG. 2 , in practice each end of the Faraday cage  50  is covered with the conductive screen (or plate, mesh, foil, or other conductive material) forming the exterior plate  52 , with insulated through-holes for passing the center tap connection, the power supply +/−12 VDC power leads, and connections to the secondary winding  40  of the resonant transformer  45 . 
       FIG. 3  depicts the steps of a method  100  of receiving power from the earth. A grounding electrode is disposed below the surface of the earth (block  102 ). A high voltage power supply, a pair of spark gap electrodes, and a resonant transformer are disposed within a coupling capacitor that also functions as a Faraday cage. The shield of the Faraday cage is electrically connected to the grounded plate of the coupling capacitor (block  104 ). The coupling capacitor and Faraday cage may, in one embodiment, resemble that depicted in  FIG. 2 . The Faraday cage completely encloses the electronics, with insulated through-holes for passing electrical conductors. 
     The grounding electrode is coupled to a center tap of a primary winding of the resonant transformer via the coupling capacitor (block  106 ). This capacitively couples the center tap of the primary winding to the grounding electrode. The primary winding of the resonant transformer is excited with a high voltage pulse generated by applying a high voltage (i.e., from the high voltage power supply) across the spark gap electrodes, causing a spark, and coupling the high voltage pulse into the primary winding (block  108 ). The high voltage pulse triggers in-rush current into the resonant transformer, for example in the range of 0.1 to 200 Hz. As used herein, the term “in-rush” current refers to broadband ELF electromagnetic waves from the ground, between 0.1 and 200 Hz, that respond to a lightning strike or a spark in the spark gap. In-rush current balances the potential difference between cloud and ground in the case of lightning, and the voltage difference across the spark gap electrodes in the case of a spark. 
     AC power from a secondary winding of the resonant transformer is converted to a useful form (block  110 ), such as by being rectified to DC, filtered, and converted to a useful voltage and current. The DC output may be converted to a useful form, such as AC current at a predetermined voltage and frequency, e.g., 120 V 60 Hz., such as by an inverter. 
     The present invention may, of course, be carried out in other ways than those specifically set forth herein without departing from essential characteristics of the invention. The present embodiments are to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.