131results about How to "Low high frequency loss" patented technology

The invention discloses a broadband wide temperature range high-power density low-loss manganese-zinc soft magnetic ferrite material. The material comprises main ingredients, an auxiliary ingredient A and an auxiliary ingredient B, wherein the main ingredients comprise the following components in percentage by weight: Fe2O3, MnO and ZnO; based on the weight of the main ingredients, the auxiliary ingredient A comprises at least three of CaCO3, Nb2O5, NiO, SnO2 and Co3O4; and the auxiliary ingredient B comprises at least three of SiO2, Y2O3, K2CO3, Al2O3, CuO, MoO and Bi2O3. The preparation method of the material sequentially comprises the following steps: primary batching, primary sanding, pre-sintering, secondary batching, secondary sanding, performing component analysis, performing spray granulation, molding and sintering. The material disclosed by the invention has low loss in a temperature range from 20 DEG C below zero to 120 DEG C under the conditions of 100-500KHz and 100-200mT, and has high magnetic conductivity and high high-temperature saturation flux density. Compared with the conventional material, the material disclosed by the invention is energy-saving and can enable a switching power module to be miniature and efficient.

The invention provides a nanocrystalline magnetically soft alloy, an amorphous magnetically soft alloy and preparation methods of the nanocrystalline magnetically soft alloy and the amorphous magnetically soft alloy. The nanocrystalline magnetically soft alloy comprises the compositions of Fe, Cu, Si, B, and Nb, and further comprises at least one element between Mn and Cr, wherein the atomic percentage content of each element at the at least one between the Mn and the Cr is not more than 3.5 at%. The antiferromagnetism of the Mn element and/or the Cr element is utilized, and a heat treatment mode of multi-stage rate annealing is combined, so that the high-frequency magnetic permeability of the magnetically soft alloy is improved, the high-frequency loss of the magnetically soft alloy is reduced, and the high-frequency magnetic performance of the magnetically soft alloy is improved; meanwhile, the crystallization temperature interval is narrower, and the heat treatment temperature interval is wider, so that the high-quality nanocrystalline magnetically soft alloy or the high-quality amorphous magnetically soft alloy are obtained favorably and the preparation cost is reduced; and inaddition, the oxidation resistance of the Mn element and/or the Cr element is further utilized, so that the tolerance of impurities is improved, the surface of an amorphous strip is prevented from being crystallized, the amorphous forming capacity is improved, and the high-quality magnetically soft alloy can be prepared through low-purity commercial raw materials.

The invention discloses a NiCuZn ferrite material and a preparation method thereof. The ferrite material comprises a main component and an additive. The main component is composed of 47-49 mol% of Fe2O3, 15-22 mol% of NiO, 25-30 mol% of ZnO, 4-7 mol% of CuO and 0.1-0.5 mol% of Co2O3. The additive is composed of A and B, wherein A accounts for 0.1-0.5 wt% of the whole material, and B accounts for 0.1-0.5 wt% of the whole material. A is BBSZ glass; and B is one or two of Ta2O5, SiO2 and SnO2. The nickel-zinc ferrite soft magnetic material disclosed by the invention has the characteristics of high initial permeability and low loss; under the frequency of 13.56 MHz, mu' is greater than 150, and mu' is less than 2; and the nickel-zinc ferrite soft magnetic material is very suitable for producing NFC (near field communication) ferrite magnetic sheets by an LTCC (low temperature co-fired ceramic) running technique.

The invention discloses a processing method of an electromagnetic shielding magnetic material. A soft magnetic alloy magnetic material strip is wound into a soft magnetic alloy magnetic material ring,and the ring is installed a thermal processing furnace; protection gas is injected into the thermal processing furnace and the furnace is heated after the furnace is vacuumized, the furnace temperature is kept, a longitudinal magnetic field and a transverse magnetic field are exerted on the magnetic material through an alternating pulse current A and an alternating pulse current B, and cooling isconducted; after the thermally-processed soft magnetic alloy magnetic material ring is attached to double-sided adhesive tape with a PET base material to form a tape-covered magnetic material strip belt, ultrasonic vibrating, roller pressing and smashing are conducted on the tape-covered magnetic material strip belt to form soft magnetic alloy roller pressing strip belts, and the soft magnetic alloy roller pressing strip belts and multiple pieces of double-sided adhesive tape are overlapped alternately and pressed into a soft magnetic alloy composite overlapped strip belt of a sandwich structure. The magnetic material processed through the method has the advantages of being high and constant in magnetic conductivity, high in frequency and temperature stability, low in high-frequency vortex loss and high in electromagnetic transmission and conversion efficiency.

The invention discloses an MnZn ferrite material in a lean iron formula; the material is prepared from main components and auxiliary components, wherein the main components and the molar percentage are as follows by oxide: Fe2O3: 45 to 49mol percent; MnO: 31.7 to 34.5 mol percent; and the balance ZnO; the auxiliary components and the weight percentage are as follows by oxide: SnO2: 0.1 to 0.5 weight percent; ZrO2: 0.1 to 0.5 weight percent; the invention also relates to a preparation method of the MnZn ferrite material in the lean iron formula, which comprises the following steps: (1) material preparation; (2) primary ball milling; (3) pre-burning; (4) secondary ball milling and doping; (5) adhesive adding and granulation; (6) forming; (7) sintering; the invention controls the content of the main components, particuarlly adopts lean iron, adds special auxiliary components into the main components, so as to prepare iron material which has higher resistivity, lower high-frequency loss, and simultaneously has higher saturation magnetic induction, higher curie temperature and other excellent integrated performance; and the preparation method of the invention not only has low cost and simple process, but also strictly controls the temperature curve, and carries out atmosphere protection.

The invention discloses a power factor correction (PFC) circuit and a control method. According to a power frequency cycle, a first controllable switching device (S1) or a second controllable switching device (S2) is controlled to be turned on or off; in a power frequency positive half-cycle, the first controllable switching device (S1) is turned off while the second controllable switching device (S2) is turned on; and in a power frequency negative half-cycle, the second controllable switching device (S2) is turned off while the first controllable switching device (S1) is turned on. A main power current loop which is continuously switched on is provided through a low-impedance path of the first controllable switching device (S1) or the second controllable switching device (S2). By replacing a slow recovery diode with the controllable switching devices, the influence of a junction capacitance effect is eliminated, a reverse current of each switching cycle is remarkably reduced, the high-frequency loss of a line is reduced, and the efficiency of the PFC circuit is improved. By the invention, an electromagnetic interference (EMI) effect can be improved, the quantity of components is decreased, and efficiency and power density are improved.

The invention discloses a wire coil for an electromagnetism electric rice cooker and a coiling method thereof. The wire coil comprises a coil disk support, a magnetic strip and an enamel-cover stranded wire. Coiling grooves are formed on the curved surface of the concave surface of the coil disk support. The enamel-cover stranded wire is sequentially coiled into the coiling grooves. The magnetic strip is arranged on the convex surface of the coil disk support. An inner hole for insertion of one end of the enamel-cover stranded wire is formed in the center of the inner side of the coil disk support. At utilization time, one end of the enamel-cover stranded wire passes through the inner hole of the coil disk support, and then is coiled from inside to outside in the anticlockwise direction along the coiling grooves, when coiled through a wire jumper slot, the enamel-cover stranded wire is coiled outward for one circle, and after wire coiling is finished, a boss is heated and compressed so as to block the enamel-cover stranded wire. The wire coil is quick in heat dissipating, dense and even in generated excitation wire, economic and environment-friendly, and realizes three-dimensional heating.

The invention provides a preparation method of low-loss nano crystal soft magnetic alloy. In the method of the invention, when crystallization heat treatment is performed on a strip obtained in a quenching technology, a heat treatment process is divided into four steps: step I, applying a magnetic field for thermal insulation in a copper cluster precipitation temperature zone along a length direction of an alloy strip; step II, performing thermal insulation in an optimum potential heat release temperature zone under a magnetic-field-free condition; step III, applying the magnetic field for thermal insulation in an optimum crystallization and growth temperature zone of alpha-Fe-phase nano crystal grains; and finally, applying the magnetic field for thermal insulation at a temperature less than the copper cluster precipitation temperature along a width direction of the strip. Compared with an existing heat treatment method, the method can reduce the high-frequency loss of the nano crystal soft magnetic alloy and can improve the comprehensive performance of the nano crystal soft magnetic alloy.

The invention discloses a paint dipping method for bonding an amorphous C type magnetic core by pure resin, which is characterized in that the method comprises the following steps of: (a) putting the magnetic core into sealable containers; (b) carrying out vacuum pumping on the containers; (c) pumping pure epoxy resin paint into the containers and immersing the magnetic core; (d) carrying out vacuum pumping on the containers, pressurizing and keeping the pressure to 0.4 to 0.6MPa for 40 to 80 minutes; (e) decompressing and discharging the epoxy resin paint; and (f) taking the dipped magnetic core out of a vat and draining. The heating temperature of the pure epoxy resin paint added in the step (c) needs to be kept to be 60+/-5 DEG C. The invention also discloses special equipment adopting the method, which comprises two sealable containers with covers, wherein a heating device is also arranged on the two sealable containers with the covers, the two sealable containers with the covers are communicated with a pipeline and are also connected with vacuum pumping and pressurizing pipelines, and a valve is arranged on the pipeline. The process method has the advantages of good paint dipping effect and convenient operation.

The invention discloses a wire coil for an electromagnetic rice cooker and a coiling method. The wire coil for the electromagnetic rice cooker comprises a support, a magnetic stripe and a stranded wire. The coiling method includes the following steps of firstly, dividing the stranded wire into two parts; secondly, separately coiling one part of the stranded wire on the outer surface of the support; thirdly, coiling the other part of the stranded wire on the bottom surface of the support; and fourthly, mounting the magnetic stripe on the support. During use, different parts of the stranded wire are coiled separately and gaps are reserved among turns of the stranded wire. Therefore, the wire coil compared with the prior art has the advantages that insulation distance between each two adjacent turns is increased, probability of short circuit among the turns in case of transient overvoltage and overcurrent is reduced, probability of direct short circuit among the turns as a result of failure of insulation caused by thermal ageing of insulation materials of wires is reduced, high-frequency coil loss caused by high-frequency proximity effect generated by compact arrangement of the turns is reduced, and heat of the wire coil is easy to radiate, so that uniform heating in large area of the rice cooker is facilitated.

The invention discloses a novel wire insulating material and relates to the technical field of electric engineering. The insulating material contains, by weight, 40-50 parts of nano-ceramics, 10-19 parts of polyurethane, 20-40 parts of chlorinated polyethylene rubber, 15-22 parts of silicon carbide, 2-8 parts of barium sulfate powder, 1.8-4.2 parts of sodium silicate, 2-5 parts of rubber, 8-11 parts of xylenol, 2-6 parts of iron oxide powder, 1.5-1.9 parts of sulphur, 9-17 parts of oxalic polyester, 12-16 parts of diglycidyl cyclohexanedicarboxylate, 4-12 parts of meerschaum, 2-7 parts of asphalt, 4-8 parts of an adhesive and 6-10 parts of a plasticizer. According to the novel wire insulating material, nano-ceramics is used as the main raw materials, and the other raw materials function together and cooperate with each other. Thus, the insulating material has good insulating properties, high strength, high temperature resistance, low high-frequecny loss, good humidity resistance, excellent flame retardancy and ageing resistance and long service life, and is appropriate to be used as a wire.

The present invention discloses a trapezoid-like staggered double-gate slow wave structure. On the basis of the staggered double-gate slow-wave structure, a trapezoidal gate is adopted at the bottom, a rectangular gate is adopted in the middle, and a circular electron beam channel is formed in the rectangular gate; the trapezoidal gate and the rectangular gate form trapezoidal-like gates, and the trapezoidal-like gates are sequentially arranged in a staggered mode in a longitudinal direction, namely a transmission direction. Tests show that the dispersion characteristic of the trapezoid-like staggered double-gate slow wave structure is improved, the broadband is wider, the high-frequency loss is greatly reduced; and meanwhile, the coupling impedance value is higher because the axial field components of the electron beam channel are more concentrated, which means that the interaction capability of an electron beam and an electromagnetic wave is increased, and further the output power, the gain and the interaction efficiency of a traveling wave tube are improved.

The embodiment of the invention relates to the field of wireless charging, and provides a heat treatment process of an amorphous soft magnetic material, which comprises the following steps: in a magnetic field furnace containing an amorphous soft magnetic material, a sectional temperature rise is carried out, and the sectional temperature rise includes a first stage temperature rise, a second stage temperature rise and a third stage temperature rise. Wherein the first annealing temperature of the first heating step is 445 DEG C to 455 DEG C; the second annealing temperature of the second heating step is 465-475 DEG C; the third annealing temperature of the third heating step is 535 - 545 DEG C. In the heat treatment process, the heat treatment process of segmented heating makes the soft magnetic materials have excellent soft magnetic properties, high permeability, high magnetic inductance, low high frequency loss, reduce coercivity and other excellent properties. In addition, the invention also provides an amorphous soft magnetic material, which has excellent soft magnetic properties after the heat treatment process.

The invention relates to an iron-based soft magnetic composite material and a preparation method thereof, and belongs to the technical field of soft magnetic composite material preparation. The preparation method comprises the following steps: carrying out ball milling treatment on pure iron powder; coating the pure iron powder with an insulating layer; performing normal-temperature compression molding; placing the pressed sample in an annealing furnace, filling with nitrogen, stabilizing the pressure to 0.02-0.04 MPa, and heating the sample to 250-270 DEG C, wherein the heating rate is 15-18 DEG C/min; then reducing the heating rate to 3-5 DEG C/min, performing heating to 400-450 DEG C, and keeping the temperature; performing heating to 550-600 DEG C at a heating rate of 15-18 DEG C/min, preserving heat for 5-20 minutes, cooling the sample to 200 DEG C or below along with the furnace, and performing discharging. Through a multi-stage heat treatment method, organic matters such as a lubricant in the material are discharged to the greatest extent in the heat treatment process, and the defects such as pores and non-magnetic impurities are reduced; and the uniformity and integrity of an insulating coating layer on the surface of the powder are kept.

The invention belongs to the technical field of microwave rectification, and provides a small-signal broadband voltage doubler rectifier with load adaptability. The rectifier mainly comprises an upper microstrip structure, an intermediate dielectric substrate and an underlying metal floor. The upper microstrip structure includes an input impedance matching network, a load adaptive regulation network and a first order voltage doubler rectification network, wherein the input impedance matching network consists of a 50 ohm microstrip line input, three pairs of open short circuit branches, three sections of impedance transformation branches, and a matching inductor; the load adaptive adjustment network consists of two sections of width tapered branches and a centrosymmetric fishbone-shaped branch; and the first order voltage doubler rectification network consists of an energy storage blocking capacitor, an energy storage filter capacitor, a rectifier diode, a load resistor, a metal pad and a ground hole. By adjusting the size of the input impedance matching network and the load adaptive regulation network, the small-signal broadband voltage doubler rectifier achieves good conversion efficiency of the rectifier over a broadband wide load range.

The invention discloses a microstrip antenna with the phase shifting function. The microstrip antenna comprises a substrate, a metal ground plane, a signal transmission line and a radiation patch, wherein the metal ground plane is located on the upper surface of the substrate. The microstrip antenna further comprises a ferroelectric dielectric layer, the metal ground plane is located on the lower surface of the ferroelectric dielectric layer, the signal transmission line is attached to the upper surface of the ferroelectric dielectric layer, and a direct-current bias voltage and a high-frequency electromagnet wave signal are superimposed and are added between the signal transmission line and the metal ground plane. The microstrip antenna has the advantages of being simple in structure, small in high-frequency loss, low in noise, low in cost and the like.

An alkalescent chemical silver electroless plating solution, which comprises: 0.01˜20 g/L silver ion or silver complex ion, 0.1˜150 g/L amine complexing agent, 0.1˜150 g/L amino acids complexing agent, and 0.1˜150 g/L polyhydroxy acids complexing agent. The alkalescent chemical silver plating solution provided by the present invention is able to overcome problems existing in acidic chemical silver plating processes commonly used at present. These problems include gnawing and corrosion of copper wires, lateral corrosion and difficulty of plating silver in blind holes, presence of solder ball voids and low strength of soldering. The silver layer plated by said silver plating solution possesses characteristics of high corrosion resistance, low contact resistance, no electromigration, high welding strength, and avoidance of bubbles produced in the solder when the plating pieces are being welded.