25 results about "Electromagnetic interference" patented technology

The invention relates to a device for detecting the life of press keys, comprising a body (1), the bottom of which is provided with a base board (2) extending forwards and used for placing a tested piece (12). The device is characterized in that the body (1) is connected with at least one cylinder (4) which can push against or loosen the press keys on the tested piece (12), the cylinder (4) is connected with an external gas source by an airway tube (10), and the airway tube (10) is connected with a valve used for controlling the cylinder (4). Compared with the prior art, the device has the following advantages: the structure of the device for detecting the life of the press keys is simplified to a maximal degree by applying the pneumatic principle and effective finger-simulated key pressing action by the cylinder, thus providing guarantee for realizing high reliability, high precision and long life of the detecting device, preventing the workpiece from being interfered by electromagnet in the process of detection and solving the life detecting problem of mini press keys of dense layout effectively, and simultaneously, the press force of the cylinder can be movably adjusted according to the bearing pressure of the press keys of the tested piece.

The invention discloses an all-fiber current transformer and a method thereof, aiming to overcome the defects that a traditional electromagnetic current transformer is easily subjected to electromagnetic interference and has complicated insulation structure, magnetic saturation existence and the like. The technical scheme of the invention comprises the following steps of: demodulating light output by a light source into X-axis polarized light and Y-axis polarized light by a Y-branch integrated optical phase modulator; converting into sinistral circular polarized light and dextral circular polarized light in a lambda/4 retarder; generating a magnetic field by a current in a lead due to the faraday effect; returning the two beams carrying faraday effect phase information to the Y-branch integrated optical phase modulator to intervene when beams in optical fiber is transmitted around the lead; and enabling an interference result to enter a subsequent treatment system from the optical fiber coupler to acquire the faraday effect phase information at the measuring point. The invention avoids the hidden danger of ferromagnetic resonance and magnetic saturation by adopting the optical fiber as a sensing medium and has a series of advantages of high detection accuracy, good environmental suitability, and the like.

Embodiments of electromagnetic interference (EMI) shielding containers are disclosed according to the present invention. The EMI shielding containers are especially useful for protecting sources of electronic evidence from EMI contamination prior to data extraction. However, the embodiments of EMI shielding containers of the present invention may be used in any context where a wireless device is to be shielded from transmitting or receiving electromagnetic signals. Embodiments of methods of using EMI shielding containers to extract data from electronic devices are also disclosed.

The present invention relates to a new process of synthesizing conductive polymers from monomers substituted with amine group. The process provides simple synthesizing steps for the conductive polymers without using other additives such as stabilizers or emulsifiers. The conductive polymers synthesized according to the present invention have highly enhanced solubility in common organic solvents and electrical conductivity compared to conventional conductive polymers. Therefore, the conductive polymers synthesized according to the present process can be utilized in applications that require high electrical conductivity, for example an electromagnetic interference shield or a transparent electrode of thin film, as well as in specific applications such as various conductive films, fibers, polymer blends, battery electrodes or conductive etch mask layers.

A liquid crystal display device is provided which is capable of reducing EMI (ElectraMagnetic Interference) noises while simultaneously responding to requirements for the high-speed transmission of image data, miniaturization and thinning of a signal processing board. A timing controller outputs, in accordance with an input data signal and input clock signal, a data line driving circuit controlling signal, internal data signal, internal clock signal to a data line driving circuit and outputs a scanning line driving circuit controlling signal to a scanning line driving circuit. The timing controller has a clock signal frequency setting mode in which a frequency of each of clock signals is set to a different value and the clock signals are supplied to the data line driving circuits and other data line driving circuits in one region and another region.

The invention discloses a structure for inhibition of electromagnetic wave interference, and a flexible printed circuit comprising the same. The structure for inhibition of electromagnetic wave interference is composed of an insulating layer, an electromagnetic wave absorbing layer, an electromagnetic wave shielding layer and a conductive adhesion layer. The electromagnetic wave shielding layer has a top surface and a bottom surface which are opposite to each other. The electromagnetic wave absorbing layer is formed on the top surface of the electromagnetic wave shielding layer. The insulating layer is formed on the top of the electromagnetic wave absorbing layer. The conductive adhesion layer is formed on the bottom surface of the electromagnetic wave shielding layer. The structure for inhibition of electromagnetic wave interference has electromagnetic wave interference shielding and absorbing functions, exhibits excellent softness and flexibility and is especially suitable for being applied to electronic communication products.

The invention relates to a semiconductor lighting driving circuit which is compatible with a thyristor dimmer and a voltage input type dimmer. The semiconductor lighting driving circuit comprises a rectification filtering circuit, a power factor correction (PFC) circuit, a control circuit and a conversion circuit, wherein the rectification filtering circuit is used for converting an alternating current which comes from an alternating current power supply into a direct current; the PFC circuit is used for performing voltage reduction on the direct current; the control circuit is used for generating a pulse width modulation (PWM) control signal according to the direct current which is subjected to voltage reduction or an output voltage of the voltage input type dimmer; and the conversion circuit is used for supplying electric energy to a semiconductor lighting device according to the PWM control signal. The semiconductor lighting driving circuit is compatible with the thyristor dimmer and the voltage input type dimmer, can steadily operate in various kinds of dimming modes, and is high in generality. The semiconductor lighting driving circuit can independently operate, and the semiconductor lighting driving circuit and other circuit modules can conveniently form a product with high cost performance. Moreover, with the PFC circuit, the electromagnetic interference of the circuit can be remarkably reduced, so that the circuit operates more steadily and more reliably.

The invention discloses a boosted circuit and a signal output method. The boosted circuit comprises a boosted module, a boosted control module, a ripple signal generation module and a voltage given signal generation module. The boosted control module carries out sampling on an inductance current signal of the boosted module and an output voltage signal. According to a ripple signal, a voltage given signal, the voltage signal and the inductance current signal, wherein the voltage signal and the inductance current signal are acquired through sampling, a driving pulse signal is generated. The boosted module completes a boost change to an input voltage signal under the control of the driving pulse signal and provides direct voltage signal output possessing a ripple component. Because the ripple signal generation module is newly added, the boosted module outputs a voltage signal possessing the ripple component. A backward-stage direct current/direct current link directly generates a jitter frequency effect because the input voltage signal possessing the ripple component so that an electromagnetic interference problem of a power supply system is alleviated.

In one embodiment, an integrated circuit structure includes one or more integrated circuit elements operable to generate an electromagnetic field when an electric current is applied to the integrated circuit element. The structure also includes an encapsulating compound substantially surrounding the one or more integrated circuit elements. The encapsulating compound includes a packaging material and an electromagnetic field-attenuating material operable to attenuate the electromagnetic field emitted by one or more of the integrated circuit elements, the electromagnetic field-attenuating material disposed within at least a portion of the packaging material.

The invention discloses a circuit board with a static protection structure, which comprises an I/O interface, a static protection device, a discharge circuit, a protection ground area and a working ground area. The protection ground area surrounds the outer side of the working ground area, the discharge circuit is connected between the two areas, and the protection ground area at least comprises one positioning hole, wherein the positioning hole is used for fixing the circuit board and introducing the static electricity of the protection ground area into a ground line or the ground; and the ground wire end of the I/O interface is connected with a static protection device and the positioning hole in series in sequence. The danger of static electricity on the circuit can be effectively prevented by using the scheme; because the structure of the circuit board is provided with a circle of unclosed metal conducting layer, electromagnetic interference can also be effectively prevented, and the electromagnetic compatibility of the circuit board is enhanced.

The invention provides a small and portable satellite signal positioning device for a Beidou second-generation navigation system. The device comprises a lower shell, a battery, a battery cover, a circuit board, a Beidou antenna and an upper shell in sequence from bottom to top. The circuit board is in a receding design. The two sides of the circuit board are provided with shielding covers for isolation. According to the satellite signal positioning device for the Beidou second-generation navigation system, a Beidou module is placed in one shielding cover, a system circuit is placed in the other shielding cover, the Beidou module and the system circuit are arranged on the two sides of the circuit board respectively, and the circuit board is of the receding design so as to reduce the electromagnetic interference. The satellite signal positioning device for the Beidou second-generation navigation system is separated from an original Beidou system with the large size, and can be independently placed at the place with the strong signal, the signal receiving quality is greatly improved, and the wireless invisibility is good. The satellite signal positioning device is small in size and convenient to carry.

The invention discloses a differential multi-bit through silicon via structure and a preparation method thereof. the differential multi-bit through silicon via structure comprises a silicon substrate,a first dielectric layer, a first reference line, a second dielectric layer, a carbon nanotube bundle, a third dielectric layer, a second reference line, a first metal bonding pad, a second metal bonding pad, a third metal bonding pad and a fourth metal bonding pad. According to the structure, the carbon nanotube is used as a transmission channel, and four metal bonding pads are arranged at the two ends of the carbon nanotube to form two signal transmission channels, so that the positive signal and the negative signal are transmitted respectively; the number of I/O ports between layers is doubled without enlarging the extra chip area; by virtue of the differential structure design of the positive signal and the negative signal, common mode noise and electromagnetic interference can be effectively inhibited, so that the transmission quality of the high-speed signals is improved, the size of the differential transmission structure is remarkably reduced, and the occupied area of the differential transmission structure is reduced, and the utilization rate of the chip area is effectively improved.

The invention discloses a heat radiation device of an electronic component, and the heat radiation device is simple in technology, resistant to electromagnetic interference and low in cost. The heat radiation device of a composite structure includes a heat conduction mechanism in the inner layer and heat radiation plastics in the outer layer, the heat conduction mechanism includes metal sheets or heat conduction tubes, the metal sheets are copper or aluminum sheets, the heat radiation device of a square structure is provided with radiating fins, the radiating fins are arranged in a vertically and horizontally staggered way to form grooves, and the edge of the heat radiation device is provided with at least one positioning mechanism. The heat radiation plastics have high heat absorption and a horizontal heat radiation function but almost no conductive performance, so that electromagnetic waves are not generated; compared with a heat radiator of pure metal in the same size, metal in the heat radiation device is lighter, and the cost is reduced effectively; the insulation performance is high; and electromagnetic wave interference generated in heat radiation of metal is avoided effectively, and convenience is provided for signal transmitting and receiving.

The invention discloses a multi-cavity bidirectional piezoelectric pump excited by a piezoelectric transducer and a pumping method thereof, and belongs to the field of fluid machinery. The multi-cavity bidirectional piezoelectric pump is characterized in that valve cavity cover plates, a pump cavity cover plate and a pump body are sequentially connected, two valve cavity elastic thin films are arranged at the bottoms of through holes of the two valve cavity cover plates, the tail ends of two valve cavity bending transducers are rigidly connected with the centers of the surfaces of the two valve cavity elastic thin films, a pump cavity elastic thin film is arranged at the bottom of a through hole of the pump cavity cover plate, the head end of a pump cavity bending vibration transducer is fixed in the pump cavity cover plate through a bending vibration transducer connecting piece, the tail end of the pump cavity bending vibration transducer is rigidly connected with the lower surface ofthe pump cavity elastic thin film, two valve cavity annular sealing rings are tightly pressed on the pump body through the valve cavity cover plates and the two valve cavity elastic thin films, and apump cavity annular sealing ring is tightly pressed and fixed under the pump body through the pump cavity cover plate and the pump cavity elastic thin film. According to the multi-cavity bidirectional piezoelectric pump excited by the piezoelectric transducer and the pumping method thereof, an adopted piezoelectric transducer vibrator has the advantages of being large in output force, high in response speed, free of electromagnetic interference and the like, and can realize the micro-liquid transfer of large pressure and flow.

EMI caused on a sensitive pin by large electric current flowing through a load pin when driving a high load is reduced or substantially eliminated. An equal amount of current, but in opposite direction, is caused to be flown in another pin (“third pin”) located close to the load pin. As a result, the EMI caused by the third pin cancels the EMI generated by the load pin. During a discharge phase, a fourth pin carries and equal amount of current, but in opposite direction, to that in the load pin. The third and fourth pins may be formed by power supply pin and ground pin. A control path may avoid a path from the third pin to the fourth pin during both the charging and discharging phases. In addition, the high load may be driven by a programmable driver which uses an amount of current proportionate to the extent of load, thereby avoiding parasitic currents. EMI is further reduced as a result.

The invention provides a method and system for eliminating electromagnetic interference. In addition to a first cable, a second cable for transmitting interference signals is further arranged in the system, processors are arranged at the output ends of the first cable and the second cable, the processors can extract a useful signal in the first signal based on the first signal and the second signal. In the method and system provided by the invention, signals transmitted by the first cable and the second cable need only be transmitted to the processors, no anti-interference filter needs to be installed in the molded device, so the structure of the molded device is not changed, and the electromagnetic interference can also be filtered out.