Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: A d.c. bias arrangement for increasing the efficiency of electrical power extraction from a piezoelectric transducer comprising a piezoelectric material, particularly of the electrostrictive type, contacted by first and second electrodes. The first electrode is connected directly to an electrical load connected directly to ground potential. The second electrode is connected by two in-parallel paths to the ground potential, one of the paths comprising a d.c. voltage source in series with a large bias resistor, and the other of the paths comprising a large a.c. power bypassing capacitor.

Abstract: A multiple tone signal is demodulated and synchronization is obtained by precisely locating frame boundaries in order to ensure reliable communication in the presence of anomalies such as Doppler shift, multipath propagation, and additive electronic noise. One such signal, TADIL-A or Link-11, employs multiple tone audio waveforms that are used to modulate RF carriers for the transmission of digital data. Initially, the signal is frequency divided and classified to determine if the incoming frame is a preamble, data or noise. For preamble frames, a digital filter is used to extract the 605 Hz tone in the time domain, and the resulting real-valued signal is passed through a first Hilbert transform to generate the corresponding imaginary complex-valued signal. Unfiltered data frames are passed through a second Hilbert transform and the output is multiplied by the complex conjugate of the stored Doppler reference signal to produce a Link-11 Signal stripped of Doppler.

Abstract: A float on a body of water is mechanically coupled to a piezoelectric material member for causing alternate straining and destraining of the member in response to the up and down movement of the float in response to passing waves, thereby causing the member to generate electricity. The output impedance of the float is matched to the input impedance of the member for increasing the energy transfer from the float to the member.

Abstract: An anemometer comprises an array (10) of piezoelectric pressure sensors (12), each of the sensors being mounted (e.g., on a circular mast 14) to face into a different wind direction. Electrical means are used to address each of the sensors (via contact wires (26, 28) for determining which of the sensors is generating, within a given time period, the greatest output voltage, thereby indicating the direction of the wind during such time period. In one arrangement, the amplitude of such greatest output voltage is used, via a look-up table, to determine the speed of the wind during such time period. In another arrangement, a separate, additional sensor is used to determine the wind speed.

Abstract: For the purpose of converting the mechanical energy of surface waves on bodies of water, a power generating piezoelectric structure (10) is provided comprising piezoelectric material members, preferably in the form of one or a laminate of sheets (14) of such material, each sheet having an electrode (24) on opposite surfaces thereof. Each pair of electrodes and the piezoelectric material therebetween define a power generating element, each of which is preferably dimensioned, relative to the wave lengths of selected waves on the body of water in which the generator is to be used, for increasing the efficiency of power conversion. A support means (12) is provided for maintaining the structure in a preselected position within and below the surface of the water. Preferably, the piezoelectric generating elements are flexible and are supported in such manner to allow flexure thereof in response to movement of the surrounding water.

Abstract: The combination of an optical memory and a charge coupled device (CCD) memory. Light from locations of the optical memory is projected onto locations of the CCD memory for producing charge signals for storage in the CCD memory. A complete array of columns and rows of information concurrently may be projected onto the CCD memory and then later may be read out electrically from the CCD memory a row at a time.