1124 results about "Electromagnetic noise" patented technology

A switched noise filter circuit for DC-DC converters which use the instantaneous output voltage to establish the converter's duty ratio. The converter cycles the switching element on and off for time intervals T_on and T_off, respectively. A switching control circuit includes a filter capacitance connected between the feedback node and ground, and a comparator which compares a feedback voltage V_fb with a fixed voltage V_ref; at least one of T_on and T_off is a “modulated” interval which is terminated when V_fb crosses V_ref due to the discharge of the filter capacitance. A switched noise filter circuit applies an offset voltage to V_fb during at least one of T_on and T_off, with the offset voltage disconnected from V_fb by the beginning of the modulated interval or shortly thereafter. When the offset voltage is properly applied, the effect of extraneous electromagnetic noise coupled into V_fb is reduced.

Electromagnetic Bandgap (EBG) structures are embedded between adjacent power planes in a multi-layer PCB to decrease the emanation of Electromagnetic radiation induced by power buses, signal layers, as well as to suppress the switching noise. EBG stages with different stop bands are cascaded to create rejection over a wider frequency region. The cascading can be performed in series, or may be formed in a variety of arrangements such as a checkerboard design or concentric ribbons positioned along the perimeter of the PCB. Each EBG stage is composed of conductive patches and via posts extending from each patch, which are positioned at a predetermined distance from each other. By surrounding the source of the noise with EBG stages, a sufficient suppression of electromagnetic noise over specific frequency bands of interest is achieved.

A portable device and associated method are described for use with a system in which a locating signal is transmitted from within the ground during an operational procedure. The locating signal includes a transmission frequency that is selectable from a group of discrete transmission frequencies in a frequency range and the region includes electromagnetic noise that can vary. The portable device includes a receiver having a bandwidth that includes the transmission frequency range and is operable for measuring the electromagnetic noise in the transmission frequency range to establish a frequency content of the electromagnetic noise for use in selecting one of the discrete transmission frequencies that is subsequently transmitted as the locating signal during the operational procedure. The locating signal can be transmitted from a boring tool, a pullback arrangement or an inground cable. A predicted maximum operational depth for a transmitter can be determined prior to the operational procedure.

To provide a connector that enhances the reliability of connection between the ground and a shield constituting a shell. A socket constitutes the connector together with a header which is mounted on a different printed wiring board. The socket includes a socket body which is provided with a connection recess, a plurality of socket contacts which are held by the socket body, and a pitch direction shield and a terminal direction shield constituting the shell which surround the connection recess and which prevents electromagnetic noise from coming in and out. The pitch direction shield and the terminal direction shield are provided with terminals soldered to conductive pattern of the ground.

A system for detecting electromagnetic noise in a magnetic resonance imaging (MRI) scanner environment includes an antenna configured to detect electromagnetic noise. The antenna includes a first conducting loop and a second conducting loop oriented perpendicularly to the first conducting loop. The system also includes a noise correction system coupled to the antenna and configured to receive noise signals from the antenna.

A radio-frequency connector consisting of a socket member and a plug member electrically connectable to the socket member is disclosed. The socket member or plug member has an impedance element mounted therein such that the impedance element is electrically connected to the metal casing and metal center pin of the socket member or plug member that carries the impedance element when the plug member is disconnected from the socket member, causing the impedance element to provide a terminal effect to insolate external electromagnetic noises; the impedance element is separated from the metal casing and metal center pin of the socket member or plug member that carries impedance element when the plug member is connected to the socket member.

An integrated circuit package comprises a cavity for housing an integrated circuit (IC) and an antenna provided as part of the package that is located substantially outside the cavity. The antenna may be located on the floor of the IC package that lies in the region outside of the IC cavity. Alternatively, the antenna may be located on the upper or lower surface of the lid sealing the IC package. The antenna may be placed in the floor or on a surface of the IC lid by forming depressions in the floor or lid surface and depositing conductive material in the depressions. The conductive material deposition may be by sputtering, evaporation, or other known physical or chemical deposition method. Antennas formed in the upper surface of an IC lid may be coupled to a pin of the IC package so that the antenna may be electrically coupled to a transceiver component on the IC within the package. Antennas formed in the lower surface of an IC lid or the floor of the IC package may be coupled by a conductive pin to a component pad of the IC within the package. To reduce electromagnetic noise that may be induced by the radio frequency signals emitted or received by an antenna, a grounding plane may be provided as part of the IC package. The grounding plane may be coupled to an electrical ground reference point through an IC package pin or the IC within the package.

An object of the present invention is to provide an automotive alternator achieving high output by overlapping a laminated core of a stator and yoke portions of a field rotor in an axial direction, and enabling high-speed and low-speed electromagnetic noise to be reduced by prescribing dimensional relationships in the stator and the field rotor.

In this automotive alternator, a ratio (R2/R1) between an outer radius R2 of a cylindrical portion of a Lundell-type core and an outer radius R1 of the Lundell-type core is set to a range from 0.50 to 0.54, and a ratio (Lc/Lp) between an axial length Lc of the laminated core and an axial length Lp of the Lundell-type core is set to a range from 0.55 to 0.70.

A biosensing cell assembly having a measurement loop with a test cell having an analyte reaction zone for amperometric measurement of a response current to determine analyte concentration and a noise cancellation loop arranged to be physically exposed to the same electromagnetic environment as the measurement loop. The noise cancellation loop has a predetermined impedance within a range of the impedance of the test cell analyte reaction zone and provides a current to cancel or reduce the effects of the electromagnetic environment on the measurement loop.

The invention discloses a three-phase motor stator structure and motor. The stator comprises an annular stator core and stator windings arranged on the stator core; The inner wall of the stator core is provided with a plurality of slots; the stator windings comprise two winding elements connected in a parallel mode, and each winding element comprises three branches windings connected in a star-shaped mode; each branch winding comprises an outgoing line, a plurality of conducting bars and a neutral line, which are connected in order; the conducting bars are formed by two legs and a transition part connected between the two legs in an integrated mode, and the transition part comprises two parallel straight arms part and a u-shape part connected between the straight arms part in an integrated mode; each branch winding is provided with six circles of windings along the circumferential direction of the stator core, and each circle of winding forms three turns of active winding. Optimizing the stator structure makes it low of the motor no-loads opposite potential harmonic and the electromagnetic noise, and insures the torque of the motor large enough under the condition of the maximum torque and the maximum velocity, and it is suitable for drive motor of electric vehicle.

Provided is a low-cost compressor having excellent operation stability which enables the improvement of the stability of a control circuit by shielding electromagnetic noise and the effective prevention of the vibration of a control substrate while the design flexibility is maintained at the same high level as that of conventional ones. An inverter-integrated electric compressor in which a motor is incorporated and a high-voltage circuit for motor drive including an inverter and a control substrate provided with a low-voltage circuit for control are provided in a compressor housing is characterized in that a shield plate made of a material capable of shielding an electromagnetic noise emitted from the high-voltage circuit for motor drive toward the low-voltage circuit for control is interposed between the high-voltage circuit for motor drive and the control substrate, and the shield plate and the control substrate are fixed to each other and both are fixed at a predetermined position in the compressor housing.

Provided is a highly reliable inverter-integrated electric compressor that is capable of suppressing electromagnetic noise interference from a power-system metal board on which a semiconductor switching devices are bare-mounted and preventing malfunction of the inverter device. In an inverter-integrated electric compressor in which an inverter accommodating section provided on a housing accommodates an inverter device, the inverter device includes an inverter module in which a power-system metal board on which at least semiconductor switching devices are bare-mounted and a CPU board on which is mounted a control and communication circuit having a device operating at low voltage, such as a CPU, are modularized via a resin case, wherein the inverter module has a metal shield plate supported by the resin case and interposed between the power-system metal board and the CPU board.

An electromagnetic noise suppressor of the present invention has magnetic resonance frequency of 8 GHz or higher, and the imaginary part μ″_H of complex magnetic permeability at 8 GHz is higher than the imaginary part μ″_L of complex magnetic permeability at 5 GHz. Such an electromagnetic noise suppressor is capable of achieving sufficient electromagnetic noise suppressing effect over the entire sub-microwave band. The electromagnetic noise suppressor can be manufactured by forming a composite layer 3 on the surface of a binding agent 2 through physical deposition of a magnetic material on the binding agent 2. The structure with an electromagnetic noise suppressing function of the present invention is a printed wiring board, a semiconductor integrated circuit or the like that is covered with the electromagnetic noise suppressor on at least a part of the surface of the structure.

An infrared sensor IC and an infrared sensor, which are extremely small and are not easily affected by electromagnetic noise and thermal fluctuation, and a manufacturing method thereof are provided. A compound semiconductor that has a small device resistance and a large electron mobility is used for a sensor (2), and then, the compound semiconductor sensor (2) and an integrated circuit (3), which processes an electrical signal output by the compound semiconductor sensor (2) and performs an operation, are arranged in a single package using hybrid formation. In this manner, an infrared sensor IC that can be operated at room temperature can be provided by a microminiature and simple package that is not conventionally produced.