Ocean Power Technologies, Inc.

Other

Merlin Industries, Inc.

George W Taylor

Joseph R Burns

Thomas R Welsh

James S Gerber

David B Stewart

Paul J Smalser

Michael Y Epstein

Charles B Carroll

Robert Deely

Daniel A Donegan

Thomas J Meaney

Charles Wilkerson

Eric Cross

Andrew Magion

James Gerber

Thomas Welsh

Joseph R(deceased) Burns

David B Stewant

An LED lighting fixture with a heat sink, LED arrays on angled facets, a reflector dish, and a diffuser lens are disclosed. The LED arrays are mounted at an angle on sloped facets, and the reflector intercepts a portion of light from the LED arrays, and redirects the intercepted light downward, resulting in a focused and collumnated light beam. Very little light is allowed to be projected upward above the light fixture, and less light is dispersed to the side.

Lighting fixture having enhanced light distribution performance

A wave energy converter (WEC) having an asymmetrically shaped float and a spar which move relative to each other in response to the waves. The asymmetrical float has one side longer than the other. A power take off device (PTO) is coupled between the asymmetric float and the spar for converting their relative motion into useful power. Apparatus is coupled to the WEC for: (a) orienting and rotating the longer side of the float to face and receive oncoming waves to increase energy capture when the waves have an amplitude below a predetermined value for improving the power generation of the WEC; and (b) rotating the float to orient the narrower side of the float to face and receive the incoming waves when the waves have an amplitude above a predetermined value, so as to reduce the forces to which the WEC is subjected. There is no known WEC system with an asymmetrical float which is raised and lowered by the waves.

Wave energy converter with asymmetrical float

A sheller for vegetables and fruits, particularly for legumes, having a rotatable drum with baffle plates having openings formed therethrough. The baffle plates are disposed such that the openings thereof are radially oriented opposite from one another to control dwell time of legumes in the drum.

Sheller and method of use thereof

An ocean wave energy converter (WEC) utilizes the relative motion between permanent magnet and induction coil assemblies to generate electricity. The permanent magnet assemblies and induction coil assemblies are separately housed in watertight enclosures, enabling a wide range of wave energy converter configurations, nearly unlimited stroke and obviating the need for a common magnet/coil enclosure with seals. The magnet assemblies are constructed with surface or buried magnets. The wave motion moves a magnet assembly relative to a stationary coil assembly, or vice versa. Either the magnet assembly or the induction coil assembly are made long enough to provide the generation of electricity over a desired operational range of travel. Various means are provided to maintain the spacing ('gap') between the magnetic and coil assemblies relatively constant.

Wave energy converters (WECs) with linear electric generators (LEGs)

A magnetic braking system for inhibiting excessive motion between a float and a column intended to be placed in a body of water; with the float and column moving relative to each other as a function of the waves present in the body of water. The braking system includes a permanent magnetic assembly (PMA) mounted on, and attached to, one of the float and column and a coil assembly (or a conductive plate) mounted on, and attached to, the other one of the float and column. The braking system is mounted such that motion between the float and the column is inhibited when the displacement of the float relative to the column exceeds a predetermined operating range.

Wave energy converter (WEC) with magnetic braking

Apparatus for converting energy contained in surface waves on a body of water to useful energy comprises a float from which is suspended a fully or effectively fully submerged inverted cup-shaped member having a closed top end and an open bottom end. Disposed within the top space is a compressible fluid separated by a flexible membrane from a column of water filling the bottom open end of the submerged member. Passing surface waves cause pressure variations at the bottom end of the member causing changes in the water column height and corresponding changes in the buoyancy of the member. The buoyancy changes induce vertical oscillations of the member relative to the float and known means are used for converting the relative movements of the float and submerged member to useful energy. Preferably, the float vertically oscillates in synchronization with the passing waves, and the vertical movements of the float increase the relative movements between the float and the submerged member.

Float dependent wave energy device

A wave energy converter (WEC), for use in a body of water of depth Dw, includes a tubular structure and a piston within the tubular structure where the relative motion between the piston and the tubular structure is used to generate electric power. The length (L) of the tubular structure may be selected to have a predetermined value based on the fact that: (a) the efficiency of the power generated by WEC increases as the length &ldquo;L&rdquo; of the tubular structure increases from a minimal value until L reaches an optimal value; and (b) the efficiency decreases as L is increased beyond the optimal value due to the increased mass of the water that the tubular structure and the piston have to move.

Wave energy converter (WEC)

A wave energy converter (WEC) including an electric generator for capturing energy contained in ocean waves and converting it to electrical energy at the output of the electric generator may be characterized as an effective capacitive (or inductive) element. Systems embodying the invention include an inductive (or capacitive) element inserted in the circuit between the output of the electric generator and a load in order to achieve resonance with the effective capacitance (inductance) of the WEC and so as to increase the efficiency of the power transfer to the load. In certain embodiments the load coupled to the system has an optimum value which is made a function of the frequency of the ocean waves and the effective capacitance (or inductance). The effective capacitance (inductance) of the converter varies as a function of the frequency of the ocean waves. Accordingly, systems embodying the invention may include a controller for varying the load and/or the inductive (capacitive) element coupled in the system to resonate with the converter for increasing the efficiency of the system.

Apparatus and method for optimizing the power transfer produced by a wave energy converter (WEC)

A transducer operated as power generating device is driven at a low frequency and collects energy at the low frequency rate. The collected energy is extracted at a much higher frequency. Extracting the energy at a higher frequency enables the use of components, such as inductors, having reasonable values and sizes. In one embodiment, a power extracting circuit which includes elements designed to resonate with the transducer at a higher frequency than the frequency at which the transducer is being driven is periodically switched in circuit with the transducer. Thus, the electric power generator device operated and controlled by a slowly changing source of energy (e.g., ocean waves, wind, eddies of water) may develop energy at one frequency and may be operated to transfer the energy at another frequency. The resonating circuit is switched into circuit with the transducer on the positive and negative peaks of the force driving the transducer for a time approximately equal to Tc, where Tc is equal to approximately &frac12;fo, where fo is the resonant frequency of the circuit with the switch closed. In another embodiment the load applied to the circuit is designed to have an optimum value to optimize the power transfer. Other embodiments include circuits for reliably and accurately detecting the peak(s) of the driving input signals.

Switched resonant power conversion electronics

Systems and circuits embodying the invention include means for sensing at least one of the peaks, amplitude and frequency of an oscillatory input force impinging on a power generating device for controlling the turn-on of a switch used to transfer energy collected by the power generating device to an associated load. The power generator may be a transducer such as a piezoelectric device or a wave energy converter (WEC). Sensors and sensing means embodying the invention are used to control the point in time at which power extracting circuits are switched in circuit with the power generating device. The power extracting circuit may include components which can resonate with the power generating circuit at a higher frequency than, and independent of, the frequency at which the power generating device is being operated. Thus, an electric power generator device operated and controlled by a slowly changing source of energy (e.g., ocean waves, wind, eddies of water) may develop energy at one frequency and may be operated to transfer the energy, at a selected point in time, at another frequency.

Sensors for power conversion systems

An electrical energy generator relying upon piezoelectricity includes electrical generating elements comprising electroded bodies of an electrostrictive material, e.g., polyurethane, having inherent but weak piezoelectric characteristics. A d.c. bias is applied between the electrodes for field-inducing a larger piezoelectric characteristic whereby, upon applying mechanical energy to the element, in known manner, for alternately straining and destraining the body, electrical charge is generated on the electrodes with a high mechanical energy to electrical energy conversion efficiency.

Field-induced piezoelectricity for electrical power generation

A flexible layer of piezoelectric material, e.g., a known PVDF polymer, is used for generating electrical energy for use on a water craft. In one arrangement, the sheet is laminated within a craft hull of fiberglass. Electrodes are provided for the major opposite surfaces of the layer, and an encapsulating material, e.g., fiberglass or a layer of the polymer itself, comprises the water contacting, exterior surface of the hull. In salt water, the water is one electrode, and an outer encapsulating layer is omitted. Spaced apart air pockets are optionally provided along the polymer sheet for increasing the flexing thereof in response to passing water and for inducing turbulence in the passing water. Elongated, flexible and electroded sheets, optionally including air pockets, are towed behind or beneath the craft, or are flown from a mast on the craft.

Water craft using piezoelectric materials

Disposed within a float on the surface of a body of water is a vertically suspended, resilient piezoelectric element provided with a preselected strain by a hanging weight. The piezoelectric system functions as a weighted coiled spring which is driven into oscillation in response to movements of the float in response to passing surface waves. Preferably, the natural frequency of the system is selected in correspondence with the frequency of the passing waves for causing the system to oscillate in resonance with the passing waves. Additionally, a mechanism is provided for automatically adjusting the natural frequency of the system in response to changing wave conditions for maintaining the system in resonance with the waves.

Generation of electrical energy by weighted, resilient piezoelectric

An anti-fouling device comprises a layer of piezoelectric material, preferably a poled plastic material such as a PVDF polymer, for mounting on the hull of a watercraft. The layer has electrodes on opposite major surfaces thereof, and the layers are connected to a power supply comprising a battery and a d.c. to a.c. converter. The converter generates an a.c. voltage at a frequency, e.g., 20 KHz, for causing vibrations of the layer, such vibrations serving to retard the growth of water dwelling organisms in the craft. The layer electrodes are also connected to an a.c. to d.c. converter for converting a.c. energy to d.c. energy suitable for trickle charging the power supply battery. Accordingly, during transit of the craft through the water, water induced hull vibrations cause vibrations of the layer for generating a.c. energy for storage in the battery, which stored energy is used for causing anti-fouling vibrations of the energy generating layer.

Self-powered anti-fouling device for watercraft

A display apparatus for underwater use comprises a hermetically sealed enclosed including a liquid crystal display device. The device comprises a liquid crystal cell disposed between layers of light polarizers and a light reflector. The combination of cell, polarizers and reflector displays either bright images on a dark background or the reverse. To make the edges of the cell substantially invisible, for improving readability of the display, the liquid crystal cell is surround by a matting comprising the identical layers of light polarizers and reflector used in combination with the liquid crystal cell. A common matting can be used with a mosaic of cells to create the appearance of a single, large area cell, or with several cells to display independent images.

Growing community of inventors

Princeton, NJ, United States of America

George W Taylor