摘要:
A system for providing audio information to persons in an approach path (12) includes an interaction point (14), and an approach path (12) leading to the interaction point. A parametric sound system (18) is provided, which includes a parametric speaker (20) disposed adjacent to the interaction point. The parametric sound system is configured for limited delivery of sound in a spatially limited audio zone (24) along the approach path (12), within a decibel level above ambient noise levels in the area of the interaction point (14), and sufficiently high to be heard primarily by a person progressing along the approach path (12). The interaction point can be a cashier station, and the system can also include a video display (16) configured to provide video information to persons in the approach path along with the audio information.
摘要:
A parametric loudspeaker which uses multiple piezoelectric bimorph transducers. These multiple piezoelectric bimorphs have a resonant frequency which varies from unit to unit. The phase response at and near the resonant frequency changes at a very high rate with slight changes in frequency. The associated modulator electronics have a primary carrier frequency that is optimized for maximum parametric output. This is achieved by aligning the carrier frequency with the flattest portions of the phase curve for maximum phase coordination among the multiple devices.
摘要:
A system and method is disclosed for a parametric emitter array with enhanced emitter-to-air acoustic coupling. The system comprises a plate support member having opposing first and second faces separated by an intermediate plate body. The plate body can have a plurality of conduits configured as an array of acoustic horns. Each horn can have a small throat opening at the first face and an intermediate horn section which diverges to a broad mouth opening at the second face. An emitter membrane can be positioned in direct contact with the first face and extending across the small throat openings. The emitter membrane can be biased by (i) applying tension to the emitter membrane extending across the throat openings, (ii) displacing the emitter membrane into a non-planar configuration, and (iii) capturing the emitter membrane at the first face using an adhesive substance. A variable electrical signal can be applied to the emitter membrane for propagation through the intermediate horn section and out the broad mouth opening at the second face.
摘要:
A sound emitting device (10) for providing at least one new sonic or subsonic frequency as a by-product of emitting a waveform of at least two ultrasonic frequencies whose difference in value corresponds to the desired new sonic or subsonic frequency. The device includes a parametric emitting perimeter or plurality of emitter segments (13) positioned around a central open section (15). This open section (15) is structured with a diagonal width greater than a cross-sectional diagonal of the parametric emitting perimeter. An ultrasonic frequency source (60) and sonic/subsonic frequency generator (62) arc coupled together to a modulating circuit (61) for mixing an ultrasonic frequency signal with an electrical signal corresponding to the at least one new sonic or subsonic frequency. The modulator output is coupled to the emitting perimeter (64) which comprises ultrasonic frequency emitting material for propagating the mixed waveform into air for demodulating the waveform to generate the at least one new sonic or subsonic frequency.
摘要:
A method is disclosed for generating parametric audio output based on the interaction of multiple ultrasonic outputs within air as a nonlinear medium. The method includes the step of generating an electronic signal comprising at least two ultrasonic signals having a difference in value which falls within an audio frequency range. The electronic signal can be transferred to an electrostatic emitter diaphragm which couples directly with the air as part of a single stage energy conversion process. The electronic signal can be converted at the diaphragm directly to a mechanical displacement as a driver member of a parametric speaker. The ultrasonic signals can be mechanically emitted from the diaphragm into the air as ultrasonic compression waves which interact within the air to generate the parametric audio output.
摘要:
A method for covertly creating adverse health effects in a human subject includes generating at least one electromagnetic wave at a frequency within the range of about 300 MHz (megahertz) and about 300 GHz (gigahertz). The at least one electromagnetic energy wave is pulsed at a pulse frequency within a target range of human neural oscillations. At least one ultrasonic audio wave is generated at a frequency greater than about 20 kHz (kilohertz). The at least one audio wave is pulsed at the pulse frequency. Each of the at least one pulsed electromagnetic wave and the at least one ultrasonic audio wave are remotely transmitted to the subject's brain.
摘要:
A method for covertly creating adverse health effects in a human subject includes generating at least one electromagnetic wave at a frequency within the range of about 300 MHz (megahertz) and about 300 GHz (gigahertz). The at least one electromagnetic energy wave is pulsed at a pulse frequency within a target range of human neural oscillations. The at least one pulsed electromagnetic wave is remotely transmitted to the subject's brain.
摘要:
A method for covertly creating adverse health effects in a human subject includes generating at least one electromagnetic wave at a frequency within the range of about 300 MHz (megahertz) and about 300 GHz (gigahertz). The at least one electromagnetic energy wave is pulsed at a pulse frequency within a target range of human neural oscillations. The at least one pulsed electromagnetic wave is remotely transmitted to the subject's brain.
摘要:
An ultralight coaxial dual rotor helicopter having a substantially L shaped frame. Attached to the back of the frame is a vertical shaft engine, and a pair of yaw paddles for controlling yaw of the craft. The drive shaft connects to a belt drive at the top of the frame, which transmits the engine power to a transmission and coaxial drive gear for driving the rotors. Crank actuators are provided for tilting the rotor axis to control the pitch and roll of the craft. A pilot seat and ballast tank are attached to the front of the frame. The ballast tank may be filled with a volume of water to balance the craft for the weight of the pilot. The fuel tank is located behind the pilot seat on the centerline of the helicopter, such that as fuel is used and the weight of fuel in the tank changes, the balance of the craft will not be affected.
摘要:
An antenna system for receiving electromagnetic waves of predetermined frequency range is disclosed comprising an antenna configured for receiving electromagnetic waves; and a plasma filter configured for reflecting a first electromagnetic frequency emitted from a remote source, while at the same time passing a second electromagnetic frequency, such that one of the first electromagnetic frequency and the second electromagnetic frequency is received by the antenna. The electromagnetic wave filter can comprise a power medium positioned with respect to a region of space; a composition disposed within the region of space for forming a plasma; an energy source electromagnetically coupled to the power medium such that a plasma may be formed in the region of space; and a control mechanism for varying plasma density within the region of space, wherein the plasma density will reflect a first electromagnetic frequency emitted from a remote source, while at the same time passing a second electromagnetic frequency.