63 results about "Electrostatic transducer" patented technology

A capacitive load driving circuit includes an error amplification circuit that amplifies a difference between an external input signal provided to one input terminal and a negative feedback signal provided from the following negative feed back circuit to the other input terminal; a modulation circuit that pulse-modulates the signal outputted from the error amplification circuit; a power switching circuit that switches between a power supply voltage and a ground potential or between a positive power supply voltage and a negative power supply voltage; a gate driving circuit that generates a gate driving signal for switching-controlling a switching element configuring the power switching circuit, from a modulated signal outputted from the modulation circuit; a low-pass filter that is connected to an output side of the power switching circuit and removes switching carrier components included in an output signal of the power switching circuit; an output transformer that boosts an output signal of the low-pass filter and has a primary winding connected to an output terminal of the low-pass filter; a capacitive load that is connected in parallel with a secondary winding of the output transformer; and a negative feedback circuit that performs a negative feedback from the output terminal of the low-pass filter to an input side of the error amplification circuit.

An acoustic transducer, specifically an electrostatic loudspeaker (ESL) providing curvature in two directions for improved dispersion of sound waves. The compound curvature also provides a virtual focus of the propagated sound waves for accurate reproduction of musical program material recorded with standard single-point microphones. The highly directional nature of high frequency sound waves requires that a flat or cylindrical electrostatic transducer must be physically tall to allow a listener to either recline or stand. The two-axis curved structure enables a compact form of ESL to be realized, including bookshelf type loudspeakers whereas all known commercial units are comparable in height to that of a human listener. The individual curved ESL panels can also be readily combined to create larger transducer assemblies including omni-directional units. A preferred stator panel hole-geometry is included for improved high voltage operation of coated perforated metal stator panels, and methods of forming the metal panel are described. The artistic nature of the two-dimensionally curved electrostatic transducer also lends itself to other non-traditional forms such as integration into lighting fixtures and other such architectural uses.

An electrostatic transducer includes: a class-D power amplifier that amplifies an input signal; and a low pass filter that has a plurality of pairs of inductors and capacitors, is connected to an output side of the class-D power amplifier, and serves to eliminate switching carrier components included in an output of the class-D power amplifier. An electrostatic load capacitor of the electrostatic transducer serving as a driving load is disposed at a capacitor, which is closest to the output side of the class-D power amplifier, of circuit elements forming the low pass filter, an electrostatic coupling capacitor and an output transformer are interposed between the electrostatic load capacitor of the electrostatic transducer and an inductor closest to the output side of the class-D power amplifier of the low pass filter, and a damping resistor is connected in series to a primary coil of the output transformer.

An apparatus includes a microelectromechanical system (MEMS) device. The MEMS device includes a resonator suspended from a substrate, an anchor disposed at a center of the resonator, a plurality of suspended beams radiating between the anchor and the resonator, a plurality of first electrodes disposed about the anchor, and a plurality of second electrodes disposed about the anchor. The plurality of first electrodes and the resonator form a first electrostatic transducer. The plurality of second electrodes and the resonator form a second electrostatic transducer. The first electrostatic transducer and the second electrostatic transducer are configured to sustain rotational vibrations of the resonator at a predetermined frequency about an axis through the center of the resonator and orthogonal to a plane of the substrate in response to a signal on the first electrode.

The invention discloses an electrostatic induction based metal surface contact damage on-line monitoring system and a monitoring method. The system provided by the invention contains an electrostatic transducer, a signal acquisition and processing analysis system and an auxiliary part, wherein the electrostatic transducer is composed of an electrostatic induction head, a shielding cover, an insulation part and a charge amplifying circuit; the signal acquisition and processing analysis system is composed of a computer, a signal processing program and a signal conditioning acquisition hardware; and the auxiliary part contains a sensor mounting rack. The system can be utilized to monitor metal surface contact damage on line, determine whether there is contact damage on the metal surface and determine the degree of the damage. The monitoring system and the method belong to the field of direct monitoring of damaged surface and can replace commonly-used monitoring systems and methods by secondary influence parameters such as vibration signal monitoring, temperature monitoring and the like.

The invention is directed at a communication device for performing data communication using a human or animal body as transmission medium. The communication device comprises a transceiver unit comprising at least one of a transmitter and a receiver. The communication device also comprises an electrostatic transducer for enabling data communication via a surface of the body with one or more user devices in touch with or located near (i.e. in close proximity, e.g. within a range of 0-10 mm therefrom) the body. The communication device further comprises an ultrasonic transducer for enabling data communication through the body using ultrasonic waves. Both the electrostatic transducer and the ultrasonic transducer are capacitive type transducers connected to and operated via the transceiver unit.

An electrostatic transducer (100) comprises an electrically conductive backplane member (102) having an array of through apertures (112); a spacer member (104) disposed over the backplane member (102), the spacer member (104) having an array of holes (114) therethrough, the holes (114) each having a maximum lateral dimension less than twice a minimum lateral dimension; and a flexible electrically conductive membrane (106) disposed over the spacer member (104). The transducer (100) is arranged in use to apply an electrical potential which gives rise to an attractive electrostatic force between the backplane member (102) and the membrane (106) thereby moving portions of the membrane (106) spanning said holes in the spacer member (104) towards said backplane member (102).

An electrostatic transducer of small size, particularly having a diameter of 2-30 mm, is provided with a metal housing or electrically conductive housing having at least one front sound entry opening and a print arranged on a rear side of the housing, wherein the print substantially closes off the housing and has at least one rear sound entry opening, and wherein an electronic system is arranged on the inner side of the print. The at least one rear sound entry opening is formed at the periphery of the print.

Provided is an electrostatic transducer which is small in size and has a large electrostatic capacitance, while having a durable constituent part of a conduction path, said constituent part being connected to an electrode. This electrostatic transducer is provided with a plurality of first electrode sheets, a plurality of second electrode sheets and a plurality of dielectric sheets. Each one of the plurality of first electrode sheets is provided with a first counter electrode part and a first terminal electrode part. Each one of the plurality of second electrode sheets is provided with a second counter electrode part and a second terminal electrode part. Each one of the plurality of dielectric sheets is provided with a dielectric main body, a first extending part that is interposed between a plurality of first terminal electrode parts, and a second extending part that is interposed between a plurality of second terminal electrode parts.