31results about How to "Small change in impedance" patented technology

An analogue stepless speed modulation method of direct-current non-brush motor comprises that (1), initialization, (2), judging external input shift, (3), checking the voltage difference at two ends of a motor, (4), adjusting PWM output, (5), comparing the voltage difference at two ends of the motor with the external input voltage difference reference value at two ends, until the voltage different is adjusted to demand. The invention quantizes the rotation speed of motor, tests the motor rotation speed of preset shift and the voltage difference at two ends of the motor, to reduce the change step of rotation speed of the motor. And engaged with the sequential analogue-digit converter, the invention can effectively resolve the defects of prior speed modulation method which will cause rotation speed different at different conditions of the direct-current non-brush motor, with strong stepless speed modulation uniformity and low cost. The invention can be used for stepless speed modulation of direct-current non-brush motor used b various aerators, cooling fans and heat radiation fans.

The invention provides a distribution network simulation system. The system comprises a simulation distribution network, a fault simulation device which is arranged in the distribution network to trigger a fault in the distribution network, section switches distributed in the distribution network to isolate the fault, a collecting device which is arranged in the distribution network to collect the voltage and current of each node of the distribution network, a control device which is connected with the fault simulation device, the section switches and the collecting device, a human-computer interaction device which is communicatively connected with the control device to set the fault of the distribution network, and a recorder which is arranged in the distribution network, is communicatively connected with the human-computer interaction device, and is used for recording the change of the electric quantity of the distribution network before and after the fault and feeding back the change to the human-computer interaction device. The distribution network simulation system provided by the invention can comprehensively and accurately simulate the dynamic behaviors of the distribution network under normal operation and fault condition, and is visual, broad, flexible and integral.

The invention discloses a power carrier communication system of a cable shielding layer, which comprises a plurality of power supply cable connectors, power supply cables, a plurality of cable shielding layer grounding wires, a plurality of inductive couplers, a plurality of power line carrier machines, and a plurality of data terminal equipment, wherein each power supply cable connector is in circuit connection with a cable inside a corresponding distribution substation; the power supply cables are in circuit connection between the power supply cable connectors, and the cable shielding layer is formed by the power supply cables and the a plurality of power supply cable connectors; the cable shielding layer grounding wires are in circuit connection with the corresponding power supply cable connectors; each inductive coupler comprises a primary side winding and a secondary side winding, one end of the primary side winding is earthed, and the other end of the primary side winding is in circuit connection with the corresponding cable shielding layer grounding wire; the power-line carrier machines are in circuit connection with the secondary side windings of the corresponding inductive couplers; and the data terminal equipment is in circuit connection with the power line carrier machines. According to the invention, by adopting the cable shielding layer to perform long-distance information transmission of medium-voltage carrier signals, the passage state is good, the attenuation is low and the impedance change is low.

The invention provides a pneumatic type three-parameter Weibull low-frequency ultrasonic atomizing spray nozzle. The overall vibrating direction of the spray nozzle is the axial direction. A three-parameter Weibull curve type amplitude change rod is adopted as an amplitude change rod of the three-parameter Weibull curve type low-frequency ultrasonic three-time atomizing spray nozzle. The size of metal used in the three-parameter Weibull curve type amplitude change rod is small, less heat is emitted, and the defects that amplitude rods of other shapes are large in metal size and emit much heatare overcome. According to the pneumatic type three-parameter Weibull low-frequency ultrasonic atomizing spray nozzle, by means of the high-pressure airflow effect of an air compressor on a wind inputpipeline, fog drops are subjected to atomizing of the third time on the right end face of a metal sheet. The defect that ultrathin fog drops cannot be generated easily through low-frequency ultrasonic atomizing is overcome, and the spray nozzle can be applied to the fields of atomizing cultivation, ultrasonic spraying and the like.

A microwave oven is adapted to radiating mutual reverse-phase wave to make wave guide tube impedance change reach to minimum in response to food loading variation, so then it can keep microwave outputting in constant value regardless of food loading quantity much or less, simultaneously it makes electric field in cavity to keep constant.

The invention discloses a digital-control constant-force feeding ultrasonic pusher. The invention has an ultrasonic pusher, a dynamic strain gage, an A/D converter, and a computer while they are connected. Wherein, the ultrasonic pusher has a servo-motor, a coupler, a ball lead-screw, a lead-screw sliding end, first muffle, a coupling sheath, a pressure sensor, first sheath pin, second muffle, second sheath pin, the cover of energy converter, a piezoelectricity energy converter, a variable-amplitude rod, and a throw-out knife, while they are connected. Wherein, the piezoelectricity energy converter is connected to the ultrasonic wave generator, and the coupling sheath is connected to the guide sheath and guide axle.

A cable with a non-circular ground wire is provided, including two wires, two ground wires, and an insulating tape; wherein the inner sides of the wires are in contact with each other; the ground wires are respectively arranged on two opposite sides of the wires; each ground wire at least includes a first side surface, a second side surface, and a third side surface; the first and second side surfaces respectively contact the outer surfaces of the two wires, and the shapes of the first side surface and the second side surface respectively correspond to the shapes of the outer surfaces of the two wires; the insulating tape covers the outer surfaces of the wires and the third side surfaces of the ground wires. Thereby, the mechanical properties of the cable of the present invention, such as small impedance variation of high-frequency signal transmission, transmission stability, structural flexibility and bending, can be significantly improved.

A heating device for an electric vehicle, according to an embodiment of the present invention, comprises: a water pump which is for circulating supplied water; a heating resistor which has one or moresurface type heating elements formed by means of a heating paste composition and is for heating the circulated water; a water temperature sensor which is for measuring the temperature of the hot water heated by means of the heating resistor; and a control unit which is for adjusting the heating resistor such that the measured temperature measured by means of the water temperature sensor satisfiesa set temperature value, wherein the heating paste composition comprises, on the basis of 100 parts by weight of the total heating paste composition, 3-6 wt % of carbon nanotube particles, 0.5-30 wt% of carbon nanoparticles, 10-30 wt % of a mixed binder, 29-83 wt % of an organic solvent, and 0.5-5 wt % of a dispersant, wherein the mixed binder has epoxy acrylate, polyvinyl acetal and phenolic resin mixed therein or has hexamethylene diisocyanate, polyvinyl acetal and phenolic resin mixed therein.

The invention discloses a module structure for a high-speed connector and a high-speed connector. The high-speed connector comprises a mounting base and a signal transmission module inserted into themounting base. The signal transmission module is composed of a plastic package casing and a differential signal terminal. The side surface of the plastic package case that is in contact with the mounting base is provided with a positioning hook and a wedge structure in the insertion direction. The positioning hook matches an insertion groove in the mounting base. The wedge structure matches a wedge-shaped groove on the end portion of the side wall of the mounting base. By disposing the wedge structure on the module structure, and by means of the cooperation of the wedge structure and the wedge-shaped groove, the positioning hook can enter the positioning insertion groove of the base according to a predetermined path, thereby improving the stability of the structure and ensuring the consistency of the differential impedance.

The invention relates to a circuit board, and the circuit board comprises at least one first circuit layer and at least one second circuit layer, the first circuit layer and the second circuit layer are arranged at an interval in the vertical direction, and the first circuit layer is provided with a gradual change signal line; the second circuit layer comprises a hollow area, and the position of the hollow area corresponds to the position of the gradual change signal line on the adjacent first circuit layer. Since the hollow area is hollowed according to the routing mode of the gradually-changed signal line on the first circuit layer, the thickness of the medium is increased, so that a thicker line width can be designed on the first circuit layer, and the purpose of reducing signal loss is achieved. Correspondingly, the impedance change of the area where the gradual change line signal is located can be minimized by optimizing the hollow area, so that the problem of discontinuous impedance of the gradual change line area is solved, and the quality of signal transmission on the circuit board is further improved.

The invention discloses a transition block and an optical chip packaging base, and the transition block comprises a block body made of a SiC material, wherein the front surface of the block body is provided with a signal return path and a microstrip line, the two sides of the block body are respectively provided with a metalized fixing groove, and the back surface of the block body is a gold-tin back surface. The method has the advantages of high efficiency, high compatibility, good coupling, reliable quality, high yield and low cost. The method is applied to the technical field of 5G.

The invention relates to a broadband microwave panel slot antenna which comprises a substrate (10), a radiation pole (20) and a feed network (30), the radiation pole (20) is arranged on one surface of the substrate (10), and the feed network (30) is arranged on the other surface of the substrate (10); the radiation pole (20) comprises a rectangular feeder line (21), a fan-shaped branch knot (22) and a semi-elliptical gap (23), the rectangular feeder line (21) is communicated with the fan-shaped branch knot (22), and the semi-elliptical gap (23) is arranged on the periphery of the rectangular feeder line (21) and the fan-shaped branch knot (22) to form a closed cavity; the feed network (30) forms a closed ring, and the feed network (30) covers the radiation pole (20) along the width direction of the substrate (10). According to the slot antenna provided by the invention, the rectangular feeder line, the semi-elliptical slot and the fan-shaped branch knot are arranged in a combined manner, and the interval of the slots is gradually changed, so that the impedance change of the antenna is very small, the antenna resonance effect in a broadband range is realized, and the slot antenna has a relatively good bandwidth characteristic and can meet the high-speed and high-resolution requirements of communication equipment and detection equipment.

A microwave oven is suitable to radiate different-phase microwaves to make the impedence variation of wave guide tube is minimal when it is in response to the variation of food load, so the microwave value is constant no matter how much the food load, and the electric field is constantly distributed in the cavity.