41results about How to "Reduce the number of winding turns" patented technology

The invention aims to realize that a control mode of primary side feedback is added into an asymmetric half bridge type flyback converter in a non-complementary DCM mode. For the asymmetric half bridge type flyback converter working in the non-complementary DCM mode, primary side inductance is released and is not clamped by an output end at the moment of finishing primary side excitation energy resetting. At the time, the primary side inductance, resonant capacitance, leakage inductance, and parasitic capacitance between the drain and the source of an MOS transistor start resonance oscillation; and at the moment of oscillation starting, a voltage between the drain and the source of the MOS transistor forms an "inflection point", voltages on two ends of the primary side inductance reflect voltage changes of the output end, voltages ontwo ends of an auxiliary winding have similar changes, an oscillation starting direction is just opposite to the direction of the voltages on the two ends of the primary side inductance due to a dotted terminal winding relationship, and if the inflection point is detected through the auxiliary winding and inflection point information is transmitted to a controller, the detection and control of an output voltage can be realized. Compared with the prior art, relatively high output voltage precision, linear adjustment rate and load adjustment rate of the converter can be ensured; and meanwhile, zero voltage switching (ZVS) of a primary side switch tube can be realized, the working frequency of the converter can be increased, the efficiency of the converter can be improved, and the volume of a complete machine is reduced.

The invention discloses a multi-gear fault-tolerance permanent magnetism magnetic flux switching electric machine and a fault-tolerance method thereof, belonging to a permanent magnetism fault-tolerance electric machine and a method. The electric machine comprises a salient pole stator, an armature winding and a salient pole rotor. Stator salient poles are E-shaped stator iron blocks; bar-shaped permanent magnets are embedded into a gap between every two E-shaped stator iron blocks in sequence; and stator windings which are coils from a first coil to a sixth coil are wounded on two E-shaped arms connected with the bar-shaped permanent magnets. Since the method employs the multitooth fault-tolerance permanent magnetism magnetic flux switching electric machine, the self inductance of the armature winding is increased; when the multi-gear fault-tolerance permanent magnetism magnetic flux switching electric machine uses high-coercive force permanent magnets, the short circuit current if can be restrained within the rated current iL without considerably increasing the number of turns of the armature winding. The invention has high reliability; the armature magnetic field makes small impact on the permanent magnets; the multi-gear structures of the stator and the rotor of the electric machine enable the electric machine to have small mutual inductance, strong magnetism isolating capability, big electrical inductance, strong capability of restraining the short circuit current and reduced location torque.

The invention relates to a bridge type mixing rectification circuit which is applied to an isolated and non-isolated DC/DC power source. The input side of the bridge type mixing rectification circuit is a double-end normal shock rectification circuit, and the output side is a diode and an MOS tube bridge type mixing rectification circuit. Compared with full-wave rectification, the rectification mode effectively reduces the copper loss of a transformer and greatly lowers a voltage class of a rectifying tube; and compared with full-bridge diode rectification, introduced synchronous rectification also reduces the loss of the rectifying tube. The bridge type mixing rectification circuit maximally enhances the efficiency of a medium-voltage output power source and a high-voltage output source and prevents the two-direction flow under the condition of current component assembly, thereby enhancing the reliability of a system.

The invention relates to the technical field of display devices, particularly to a rollable display device. The device comprises a shell, a driving mechanism and a flexible bearing film that are disposed in the shell, and a flexible display screen. The flexible bearing film is arranged to rotate under the driving of the driving mechanism; a first end of the flexible display screen is fixed to theflexible bearing film, a second end of the flexible display screen is arranged to extend out of the shell from an opening formed in the shell, and the flexible display screen can be rolled on the flexible bearing film and can be unfolded under the pulling of an external force. According to the rollable display device of the embodiment, the rolling number of turns of the flexible display screen canbe reduced, so that stress-strain accumulation of the flexible display screen can be reduced, the film interlayer extrusion condition of the flexible display screen is relieved, and the flexible display screen is not prone to being damaged.

The invention discloses a control method of an accelerating high-voltage power for an electron-beam punching machine and a power device thereof. The power is supplied by three-phase commercial electricity and adopts the current conversion mode of AC-DC-AC-DC, wherein, the middle inverter link of DC-AC is high-frequency inversion and the pulse-width modulation voltage regulation function can be realized in the inversion process; a dual closed-loop control mode is adopted to realize the stable regulation of the output high-voltage; an inverter consists of at least two inverter bridges, the phase difference of the output wave of each inverter bridge is distributed symmetrically, and the output wave has the same width. The power device comprises: a power network filter, an input rectifier filter circuit, the inverter, a high-frequency and high-voltage transformer, a high-voltage rectifier filter circuit, a high-voltage discharge choke circuit, a high-voltage sampling circuit, an electronic beam sampling resistor, an inverter input current detection circuit, a dual-loop control unit, an inverter drive circuit, a fault discrimination circuit and the like. The control method and the power device are characterized by the control system with high regulation speed, strong immunity, small accelerating high-voltage power ripple, high efficiency and small size and the like.

The invention discloses a speed regulation permanent magnet synchronous motor based on variable number of turns of windings. The speed regulation permanent magnet synchronous motor comprises three-phase windings, each winding comprises a plurality of serially connected series winding units, each series winding unit comprises one winding and two winding control structures, one winding control structure and the winding after parallel connection are parallelly connected with the other winding control structure, the winding control structures are used for controlling whether current is led in ornot when the speed regulation permanent magnet synchronous motor works, the connection number of turns of the series winding units is changed to control the counter potential of the speed regulation permanent magnet synchronous motor, weak magnetic current is reduced, and performances are improved. According to the speed regulation permanent magnet synchronous motor, the winding control structuresserially connected with the windings are disconnected, the winding control structures parallelly connected with the windings are closed, the windings are bypassed in a circuit-breaking manner, the number of turns of the windings connected into the speed regulation permanent magnet synchronous motor during work is decreased, the counter potential is reduced, the number of rated points is increased, and a speed regulation range is widened.

A switched mode power supply (400), comprising a transformer (410) having a primary winding (410-1), a transformer core (410-3) configured to store energy transferred thereto from the primary winding (410-1) during operation, and a secondary winding (410-2) having a first terminal (Tl) and a second terminal (T2). The switched mode power supply also has a primary side circuit (Q1, Q2, C1) arranged to generate voltage pulses and thereby to drive the primary winding (410-1) of the transformer (410), and a secondary side circuit comprising a rectification circuit connected to the secondary winding (410-2) at the first and second terminals (Tl, T2). The rectification circuit is arranged such that during a forward phase of operation of the switched mode power supply, in which the primary winding (410-1) is driven by the primary side circuit to magnetise, and store energy in, the transformer core (410-3), a current induced to flow in the secondary winding (410 -2) from the second terminal (T2) to the first terminal (Tl) is output by the rectification circuit. The rectification circuit is further arranged such that during a flyback phase of operation of the switched mode power supply, in which the magnetisation of the transformer core (410-3) is reset, a current induced to flow in the secondary winding from the first terminal (Tl) to the second terminal (T2) of the secondary winding (410 -2) is output by the rectification circuit so that energy stored in the transformer (410) during the forward phase of operation is output by the rectification circuit.

The invention relates to a winder, in particular to a textile fabric winder. The invention aims to solve the technical problem so as to provide the textile fabric winder convenient to fix cloth and capable of adjusting the winding diameter size and soothing and compacting the cloth. The textile fabric winder comprises a base, a bearing seat, a rotary rod, a first bolt, a connecting pillar, a rotating column, an adjusting device, a second spring, lifting plates, a first pressing block, a straight sliding rail, a support rod and the like, wherein the bearing seat is arranged on the right side ofthe top part of the base; the rotary rod is in interference connection into the bearing seat; a first threaded hole is formed in the left part of the rotary rod; a cross-shaped hole is formed in theright part of the connecting pillar; the left part of the rotary rod is located in the cross-shaped hole; and the first bolt is screwed in the first threaded hole. According to the textile fabric winder provided by the invention, working personnel presses one end of the cloth through the first pressing block, so that the cloth can be conveniently and quickly fixed; and through screwing a nut, thelifting plates on the upper part and the lower part are opened toward the outer side, and the cloth winding diameter size can be adjusted according to the needs, so that the winding turn number can bereduced, and the winding speed is accelerated.

The invention relates to a radio frequency power supply circuit suitable for a four-level rod mass spectrometer. The circuit has high signal transmission efficiency, high control precision and a low space radiation magnetic field. The structure of the circuit is simple and hardware cost is greatly saved. The circuit comprises a sine wave oscillation circuit, a frequency modulation circuit, an amplification circuit, a boosting transformer and a feedback loop, wherein the sine wave oscillation circuit is connected to the frequency modulation circuit and is used for generating a sine wave voltagesignal and inputting the sine wave voltage signal to the frequency modulation circuit; the frequency modulation circuit is connected to the amplification circuit and is used for modulating the frequency of the sine wave voltage signal; the amplification circuit is connected to the input side winding of the boosting transformer and is used for amplifying the modulated sine wave voltage signal; theboosting transformer is used for further amplifying the modulated sine wave voltage signal; and the feedback loop is used for collecting a sampling signal from the boosting transformer, converting apulsating alternating current voltage into a pulsating direct current voltage through a bridge rectifier circuit, then carrying out difference value operation with a backward-stage reference voltage and feeding a difference value signal back to the frequency modulation circuit so as to realize the stable control of an output voltage.

The invention discloses a single-boom gantry crane amplitude-variable compensation system and a single-boom gantry crane. The amplitude-variable compensation system comprises a lifting winding drum, an amplitude-variable compensation winding drum, a first compensation steel wire rope, a second compensation steel wire rope and an amplitude-variable steel wire rope, wherein the lifting winding drum and the amplitude-variable compensation winding drum are arranged on the turntable; the first compensation steel wire rope twines together with a first compensation pulley block and a pulley of a first lifting hook pulley block; the second compensation steel wire rope twines together with a second compensation pulley block and a pulley of a second lifting hook pulley block; two ends of the first compensation steel wire rope and the second compensation steel wire rope are respectively connected with the lifting winding drum and the amplitude-variable compensation winding drum; the first compensation steel wire rope and the second compensation steel wire rope, which are mutually symmetrical, are used for maintaining the balance of a lifting hook; the amplitude-variable steel wire rope is used for sequentially winding the first amplitude-variable pulley block and the second amplitude-variable pulley block; two ends of the amplitude-variable steel wire rope are connected with the same side of the amplitude-variable compensation winding drum, so that the amplitude-variable steel wire rope and the amplitude-variable compensation winding drum simultaneously wind in and out.

The invention provides an inflation control device of an inflatable anchor. The inflation control device comprises a pressure sensor arranged in a bag body of the inflatable anchor and used for acquiring a gas pressure signal produced by the bag body due to inflation; a piezoelectric conversion component connected with the pressure sensor and used for acquiring the gas pressure signal, and converting the gas pressure signal into current; an electromagnetic induction component connected with the piezoelectric conversion component and used for converting the current into a magnetic field, wherein the electromagnetic induction component makes action according to the magnetic field; and the inflation control component connected with the electromagnetic induction component and used for connecting with or disconnecting from the inflation device according to the action. The inflation device for the inflatable anchor can realize automatic inflation or stop inflation according to the pressure in the bag body of the inflatable anchor; and the control device is simple in operation, high in construction efficiency, adjustable in inflation pressure and capable of realizing quantitative inflation function.

The invention discloses a novel ultra-thin electromagnetic relay which comprises a contact component, a magnetic circuit component and a base, wherein the contact component and the magnetic circuit component are correspondingly matched and arranged on the base; a yokeiron/ an iron core of the magnetic circuit component is an integral type structure which takes the shape of a reversed U; a strip-shaped opening is arranged at the bottom end of a coil rack of the magnetic circuit component along an axial line of a winding tube of the magnetic circuit component, the strip-shaped opening of the winding tube extends towards two sides to cause the bottom end of the coil rack to form a through groove which is provided with a downward opening and used for embedding the yokeiron /the iron core, and the through groove is provided with a convex structure used for preventing the embedded yokeiron/ the iron core from dropping out corresponding to the inner side of the groove edge of the winding tube section. The electromagnetic relay with the structures can ensure that the magnetic circuit efficiency is promoted, and the aims of appropriately reducing the number of turns of the windings, the using amount of lacquered wires and the cost and promoting the medium voltage resistance between the output terminal and the input terminal can be achieved.

The metal powder hydraulic device comprises a rack, a feeding device, a forming device and a driving device, the forming device is fixedly connected with the rack, the feeding device is connected with the forming device, the driving device is connected with the forming device, the rack comprises a stand column, an upper cross beam is arranged at the upper end of the stand column, and a lower cross beam is arranged at the lower end of the stand column. The forming device comprises an upper die assembly, a lower die assembly and a middle die assembly, the upper die assembly and the lower die assembly are arranged in the space vertical direction, the lower die assembly comprises a guide seat, one side of the guide seat is fixedly connected with the end, away from the stand column, of the lower cross beam, a working cavity is formed in the guide seat, a guide groove is formed in the outer side of the working cavity, and the working cavity communicates with the guide groove. The middle mold assembly is arranged in the guide groove and comprises a middle mold, the middle mold comprises two mold petals, middle mold channels are formed in the mold petals, and the two middle mold channels form a mold cavity.

The invention provides a flyback converter circuit of a series active clamp. The circuit comprises a primary main power loop unit, a clamping loop unit and a secondary rectifying and filtering unit. The primary main power loop unitcomprises an input energy storage filter capacitor, a clamping capacitor, a transformer and a main power switch tube, one end of the clamping capacitor is connected with a positive terminal of voltage input, the other end of the clamping capacitor is connected with a synonym terminal of the transformer, a dotted terminal of the transformer is connected with a drain electrode of the main power switch tube, and a source electrode of the main power switch tube is connected with a negative terminal of the voltage input; the clamping loop unit is used for transferring and storing the leakage inductance energy of the transformer into the clamping capacitor and feeding back part of the energy into the transformer to be transmitted to a secondary winding; and the secondary rectifying and filtering unit rectifies pulsating voltage on the secondary winding into direct-current voltage to provide energy for an output load when the transformer is subjected to reverse excitation. According to the invention, the number of turns of the windings needed by excitation inductance can be reduced, meanwhile, drain-source voltage on the main power switch tube is also reduced, switching loss of the main power switch tube is reduced, and the circuit conversion efficiency is improved.

A stator punching plate used for an air conditioning fan motor relates to the technical field of AC asynchronous motor modification, and is characterized by comprising an annular punching plate body, wherein the middle part of the punching plate body is provided with a hollow inner round hole and an outer circle, a punching plate groove is arranged between the outer circle of the punching plate body and the hollow inner round hole, the punching plate groove is provided with a notch, a groove shoulder, a groove body and a groove top. The stator punching plate provided by the invention has the advantages that the structure is reasonable, the flux density distribution of iron cores is effectively improved, the raw material consumption of coils and the iron cores is reduced, the energy efficiency is high and the service life is long.

The present invention relates to an airplane tire and, particularly, to the crown reinforcement thereof. The airplane tire (1) includes a working reinforcement (2) located radially inside a tread (3) and radially outside a carcass reinforcement (4). The working reinforcement (2) includes at least one working dual ply (21) consisting of two radially stacked working layers (211, 212). The working dual ply (21) consists of the circumferential zigzag winding of a strip (5) having a width W over a cylindrical laying surface (6) with radius R and having, for a rotational axis, the rotational axis (YY') of the tire along a periodic curve (7). The periodic curve (7) has a period P and forms an angle A with the circumferential direction (XX') of the tire within the equatorial plane (XZ) of the tire. The circumferential zigzag winding of the strip (5) includes N periods P of the periodic curve (7) over a number T of circumferences 2 Pi R of the cylindrical laying surface (6). According to the invention, the number N of periods P of the periodic curve (7) is an integer that fits the following conditions: (a) N*(W/sin A)=2*Pi*R; (b) N*P=2*Pi*R*T, where T is an integer, (c) N*T is the lowest common multiple of N and T, and the ratio T/N is 1.8 to 2.2.

The invention discloses a multistage high-low voltage hybrid excitation standard voltage transformer and a simulation verification method thereof. The multi-stage high-low voltage hybrid excitation standard voltage transformer comprises a first-stage voltage transformer, a second-stage voltage transformer, a third-stage voltage transformer and an auxiliary voltage transformer. The invention provides a multistage high-low voltage hybrid excitation standard voltage transformer structure suitable for practical engineering. An equivalent circuit is established for the structure, the theoretical measurement accuracy of the transformer is deduced, the theoretical measurement accuracy of the transformer is verified in combination with Simulink and Matlab, and a solid foundation is laid for the design of the actual multi-stage high-low voltage hybrid excitation standard voltage transformer.