2674 results about "Cut-off" patented technology

An object is to provide a technology capable of improving a manufacturing yield of semiconductor devices by preventing scattering of irregular-shaped scraps formed at the time of dicing. To achieve the above object, for dicing lines, by which an irregular-shaped outer periphery may possibly be cut off, among a plurality of dicing lines, formation of the dicing lines starts from an outside of a semiconductor wafer, and after the semiconductor wafer is cut off partway, formation of the dicing lines is ended before reaching the irregular-shaped outer periphery formed on a outer periphery of the semiconductor wafer. For other dicing lines, formation of the dicing lines starts from the outside of the semiconductor wafer, and after the semiconductor wafer is cut off, is ended outside the semiconductor wafer.

The invention relates to detection of fault arc, wherein, fault arc cycle is recognized through at least two wave characters by gathering current waveform of each cycle; the fault arc is verified through judging whether a plurality of continuous fault arc cycles exist; if the waveform not only meets the condition that the amplitude is smaller than that of normal current or phenomenon of flat shoulder exists on a zero crossing point but also meets the condition that the waveform of positive and negative half cycles is asymmetric or di/dt is overlarge at a certain moment, then the cycle is estimated as a fault arc cycle; if a plurality of cycles continuously are estimated as fault arc cycle, then the fault arc is verified. Compared with the prior art, the technical proposal of the invention has the advantages that the fault arc can be detected during the process of normal power supply; the power can be automatically cut off within very short period, and simultaneously the fault arc current and the starting impulse current can be distinguished; the spurious trip rate is reduced.

The invention discloses a constant current constant voltage power controller and a supply converter thereof. The constant current constant voltage power controller comprises three pins: a supply pin VDD, a switch control pin GATE and a ground pin GND, wherein the GND ground pin is connected with a resistor RS, and the GATE pin and the GND pin are connected with a switch tube T1; the power controller further comprises a voltage difference detection module, a secondary pole detection module, a constant voltage constant current control module and a driving stage module, wherein the voltage difference detection module detects the voltage difference between the VDD pin and the GND pin when the switch tube T1 is turned on and cut off; the secondary pole detection module clamps the voltage of theGATE pin when the switch tube T1 is cut off so as to enable the voltage to be smaller than the breakover threshold voltage of the switch tube T1, and at the same time, the secondary pole detection module detects the current passing through the GATE pin so as to further detect the secondary output voltage and the secondary demagnetization pulse width. The invention can reduce the system cost of aflyback converter. In addition, the invention also provides a pin multiplexing method, and therefore, the cost of a control chip of the flyback converter can be greatly reduced.

The invention discloses a light-emitting diode (LED) current detection and control circuit and relates to the field of LED current detection and control circuits. The LED current detection and control circuit is technically characterized in that the circuit comprises a controller, a switching tube, a resistor, a diode, an inductor and a capacitor; when the switching tube is turned on, the resistor detects current which flows through the switching tube and the inductor, the current is fed to the controller, the switching tube and the inductor are prevented from being damaged because of overcurrent and the reliability of an LED driving power supply during working is improved; and when the switching tube is cut off, the resistor detects current which flows through a load LED, and since closed-loop control is adopted in the controller, the value of current output to the LED is very precise and is not influenced by input voltage, output voltage and inductance. The LED current detection and control circuit is suitable for all LED driving power supplies which adopt a BUCK-BOOST topology.

The invention relates to a frequency control strategy for a multiple DC (Direct Current) send-out island power grid. The frequency control strategy comprises the following steps of: 1, for the multiple DC send-out island power grid of which the system frequency is risen or reduced due to a fault, firstly, starting a first defense line and utilizing a DC system frequency limiting function to control the system frequency; 2, when the frequency exceeds a frequency operated dead zone of a dynamo governor, starting another measure in the first defense line, i.e. carrying out primary frequency modulation control by the dynamo governor; 3, when the frequency exceeds a range of 49.0 to 50.6Hz, starting a second defense line, i.e. cutting off a generator or a load according to a control strategy; 4, when the frequency exceeds 50.6Hz, starting a third defense line and carrying out high-frequency cut-off protection to cut off a generating set; 5, when the frequency exceeds 51.5Hz, enabling the generator to execute the overspeed protection action and cutting off the generating set. The frequency control strategy can be used as an actual control strategy for stabilizing the frequency of a large-scale multiple DC send-out island system to be applied to production and operation of the power grid and also can be applied to emulation calculation of related research.

A device for changing an electric wire and method for distributing power without cutting off power supply has developed for replacing the live electric line on the electric poles, relocating the electric poles and alteration of the power distribution route. Replacement operation of the live electric wire is sequentially performed by connecting new wire and separating old wire by the wire changing device mounted on each electric pole without using bypass cable. The wire changing device comprises a cross-arm fastening unit, wire replacing unit and axial-rotating unit having a central arm fixture, axial shaft, arm coupling and position locking unit. The wire changing method comprises the steps of: mounting the wire changing device on each electric pole, replacing new and old wires without cutting off power supply, arranging the wire space, installing and tightening the new wire on each LP insulator of the electric pole, and removing the separated wire.

A clock pulse with a smaller amplitude voltage than the power supply voltage of the shift register is inputted to the shift register. The gate width of a TFT that constitutes a second clocked inverter of the shift register is set wide so as to reduce fluctuation in output electric potential due to leak current of a first clocked inverter. Further, a TFT is added to a first clocked inverter. A signal with an amplitude voltage of the same level as the power supply voltage is inputted to a gate electrode of the added TFT to switch between ON and OFF. The leak current of the first clocked inverter is thus cut off.

The invention discloses a method for processing interphase short circuit of a three-phase non-effective grounding power supply system. The method comprises the following steps: when two-phase or three-phase interphase short circuit occurs in a line, maintaining one fault phase of the line to be conducted and tripping off other fault phases, and artificially grounding the other fault phase conducted with the fault phase or directly utilizing the existing grounding point; enabling a live-line phase or a neutral point of the three-phase non-effectively grounded power supply system except the fault phase to be circularly connected and disconnected with the ground, so that the live-line phase or the neutral point and the fault phase form a closed loop and generate a current pulse, and detecting the current pulse by a controlled switch; when a certain controlled switch reaches a trigger condition and cuts off a line, eliminating a fault. According to the method, the inter-phase short-circuit fault point interval can be quickly positioned, the fault can be automatically, quickly and accurately removed, the processing quality of the inter-phase short-circuit fault can be well improved, and the power supply safety is improved.

An improved structure of a flag elevating/descending device is disclosed. The flagpole is provided with an elevating/descending tube and a rotating tube to allow the flag to elevate/descend and to rotate. An elevating/descending driving device is provided at the flagpole head, and a driving strap is protruded from the driving device to mount with the elevating/descending tube so that the driving strap can extend outward and/or roll up and the flag will not wind around the flagpole when the flag is elevated or descended. The base seat of the flagpole is provided with an un-interrupted current device and a re-storage battery so that the device is operable even if the current supply is cut off.

The invention relates to a single-sided circuit board made by gluing flat wires arranged side by side with a thermosetting adhesive film. Specifically, according to one realization mode of the invention, one group of flat wires arranged side by side are directly glued by a thermosetting adhesive film, parts of the wries, which need to be disconnected are cut off, the surface of the adhesive film is directly combined with a substrate of the circuit board through hot pressing gluing to form a circuit board, soldering resisting ink or a covering film is used for soldering resisting, and bridgingconnection is realized through printing electricity conducting ink or soldering conductors. When a jack element needs to be arranged, soldering installation can be realized as long as a hole is directly drilled in a soldered spot or a hole is punched by a die. The circuit board can be made without etching. Compared with the traditional circuit board making technology, the novel technology has theadvantages of excellent environment friendliness, energy saving and material saving.

The invention discloses a control method of a relay with an inductive load, and a household appliance. A movable contact of the relay is connected with an alternating current power supply loop of the inductive load so as to execute on-off control on the alternating current power supply of the inductive load; while executing power off control on the inductive load, voltage zero crossing moment of the alternating current power supply is detected, after T*n+Delta T-T2, the power supply of a coil of the relay is cut off when the voltage zero crossing moment is detected, and the movable contact ofthe relay is controlled to act so as to cut off the power supply of the inductive load; FORMULA, wherein f is the frequency of the alternating current power supply; FORMULA is the power factor of theinductive load; T2 is the time from the moment when the power supply of the coil is cut off to the moment when the movable contact of the relay acts, and n is a natural number. In the method, the movable contact of the relay is controlled to act at the alternating current zero crossing moment, and power on and power off control for the inductive load is realized, thus, the sparking phenomenon of the relay at the cut-off moment of the movable contact is eliminated, and service life of the relay is prolonged.

A memory cell with an internal supply feedback loop is provided herein. The memory cell includes a latch having two storage nodes Q and QB, and a supply node. A gating device couples the supply node of the latch to the supply voltage. The gating device is controlled by a feedback loop coming from storage node QB. Due to the aforementioned asymmetric topology, the writing of logic “1” and the writing of logic “0” are carried out differently. Contrary to standard SRAM cells, in the hold states, only the QB storage node presents a valid value of stored data. The feedback loop cuts off the supply voltage for the latch such that the latch is no longer an inverting latch. By cutting off the supply voltage at the stable hold states, while maintaining readability of the memory cell, leakage currents associated with the hold states are eliminated altogether.

The invention provides a method and device for controlling uninterruptible operation of a wind generator system in case of faulted power grid voltage. An existing doubly-fed motor rotor-side frequency converter and a CROWBAR circuit are utilized to realize the uninterruptible operation of a DFIG (doubly-fed induction generator) wind generator system when the power grid generates the serious voltage faults. The method at least comprises the following steps: 1) detecting the voltage of the power grid; 2) triggering CROWBAR protection; 3) waiting a voltage of the power grid to recover; 4) cutting off the CROWBAR protection; 5) starting a grid-side current transformer; and 6) starting a motor-side current transformer. In the invention, motor time sequences of corresponding states of the current transformer are given when the power grid voltage is seriously asymmetrical and when the motor is in a non-voltage state; the CROWBAR protection circuit of the current transformer is used to finishthe protection for the wind generator system and the current transformer; and the method and device provided by the invention are suitable for various faults of the power grid such as a symmetric voltage fault of the power grid, an asymmetric fault of a small voltage value of the power grid, a seriously asymmetric voltage fault of the power grid and a non-voltage fault of the power grid, and meets grid-connected requirements of the wind generator system formulated by a power grid corporation. Mechanical installation of equipment is simple and the installation is convenient and quick.

The invention discloses a preparation method and a preparation device of a tungsten probe for electrical measurement of a nanometer device. The principle of the method is to obtain the tungsten probe by an electrochemical corrosion tungsten filament, wherein the tungsten filament is taken as an anode and soaked in electrolyte; the tungsten filament is lifted when the current of the tungsten filament is reduced to 20mA; and the tungsten filament is taken as a cathode by reverse current and lifted to depart from the electrolyte at the moment when the tungsten filament is cut off by corrosion, so as to obtain the tungsten probe. The tungsten tipped probe with large draw ratio can be prepared by the preparation method; meanwhile, the reverse current when the tungsten filament is cut off is detected; and the taper corner at the tip of the tungsten probe can be estimated in advance, so as to save the time and cost needed in subsequent procedure that an electron scanning microscope is needed to observe and confirm in the traditional method.

The invention discloses a winding car raw material wire fixed length control method, which is characterized in that the method comprises the following steps: mounting a circle roller which is equipped with a magnet block on spindles of the winding car; coiling the raw material wire against the circle roller; driving the circle roller to rotate when the raw material wire is wound; and mounting a hull sensor in the position corresponding to the magnet block on the circle roller to detect an impulse signal, further outputting the impulse signal in a signal processing device; counting, comparing the count value with the setting value by the signal processing device; and outputting the control signal and cutting off the raw material wire when the count value reaches the setting value. By adopting the proper method and device to control the coiling length of the raw material wire on the straight bobbin, the invention not only improves the control precision, and reduces the energy loss, but also has the advantages of simple structure, easy operation and low manufacturing cost.

The invention discloses a direct-current bus voltage buildup device based on a double-active-bridge convertor and a starting method of the direct-current bus voltage buildup device in the field of electrical and electronic engineering. According to the direct-current bus voltage buildup device, input end sampled signals of a low-voltage-side full-bridge circuit are sent to a digital signal processor through an input conditioning circuit, output end sampled signals of a high-voltage-side full-bridge circuit are sent to the digital signal processor through an output conditioning circuit, the signal output end of the digital signal processor is connected with a driving circuit, and the driving circuit controls power tubes in the low-voltage-side full-bridge circuit and the high-voltage-side full-bridge circuit to be turned on/off. When a double-active-bridge circuit is started, a high-pressure-side switching tube is cut off, a low-pressure-side switching tube is driven through narrow pulses, and a capacitor on the high-pressure direct-current side is charged through a rectified body diode of the high-pressure-side switching tube to build up direct-current bus voltage. Inductance saturation in the direct-current bus voltage buildup process can be effectively avoided, the starting method does not need hardware cost, only digital control is needed to implement the starting method, hardware circuit cost is saved, and the direct-current bus voltage buildup device can be used in control over a two-way charger.

The invention discloses an IGBT device test circuit and test method. The test circuit comprises a double-pulse test module used for testing on and off performance of an IGBT, a current endurance capability test module used for testing the current endurance capability of the IGBT under the condition of simulating the bipolar short circuit of a converter valve, an acquisition module used for acquiring the collector voltage and the emitter current of the IGBT, and a protection module used for cutting off the connection between the double-pulse test module and the IGBT when the collector voltage and/or emitter current of the IGBT exceed/exceeds a corresponding preset threshold(s). According to the invention, the switching-on and switching-off performance of the IGBT is tested by using the double-pulse test module, and the situation that the surge current impacts the IGBT under the bipolar short circuit condition of the converter valve is simulated by using the square wave current continuously output by a current source, so that the comprehensiveness and diversity of the IGBT performance test are further improved.

The invention discloses an electric energy management system and method based on a super capacitor, which relate to the technical field of electric energy management, solve the technical problem that the super capacitor cannot be accurately managed and controlled in the prior art, and judge whether the position of the super capacitor in each region is an optimal position or not. The regional power supply efficiency is improved, the regional power supply cost is reduced, the electric energy price can be better controlled, and the use quality of a user is improved; the power consumption condition of each analysis region is cut off, so that the working intensity of the super-capacitor in each analysis region is analyzed, the power consumption condition of the region is monitored in real time, power dispatching is carried out in time, and the situation that the power consumption efficiency of each region is reduced due to the fact that the power is excessively used and the power recovery is smooth and the period is long is prevented,the influencing factors of power consumption in each region are determined, and therefore, the power utilization state of the region can be analyzed according to the influence factors, and the accuracy of power utilization data monitoring is improved.

The invention discloses an inter-phase short circuit fault processing method, and the method comprises the following steps: when a two-phase or three-phase inter-phase short circuit occurs in a line, maintaining one fault phase of the line to be conducted, tripping off other fault phases, and connecting another fault phase conducted with the fault phase with a public lead; enabling the three-phase non-effective grounding power supply system to be connected with the common lead, enabling a live-line phase or a neutral point of the three-phase non-effective grounding power supply system except the fault phase to be connected with the common lead so as to form a closed loop with the fault phase and generate current, detecting current duration through controlled switches, and when a certain controlled switch reaches a triggering condition and cuts off a line, eliminating the fault. According to the method, the inter-phase short-circuit fault point interval can be quickly positioned, the fault can be automatically, quickly and accurately removed, the processing quality of the inter-phase short-circuit fault can be well improved, and the power supply safety is improved.

The invention discloses a prepayment metering control device with an automatic short message warning function. Electric charge is required to be stored in advance before electricity consumption of power consumers, when left electric charge is lower than an early warning set value, a warning short message is sent out automatically, when the left electric charge is used up, the power supply of the user is cut off automatically, and a warning short message for tripping operation due to arrearage is sent at the same time. The prepayment metering control device with the automatic short message warning function comprises a breaker or complete set equipment, the prepayment metering control device and an automatic short message warning device. According to the invention, while power supply companies' accurate charging and control to power consumers are ensured, the consumers are reminded to pay electric charge in time, and conveniences on electricity consumption are brought to users.

The invention provides a method for quickly calculating power harmonic parameters in a high-accuracy mode and belongs to analysis and automatic monitoring algorithm of power grid voltage and current waveform distortion. Firstly, a symmetrical window function is used for cutting off a sampled power harmonic signal and performing fast Fourier transform (FFT) to the cut signal, and then the same window function is used for cutting off sample data with the half length from the same starting point and performing the FFT. A fundamental wave and frequency of sub-harmonic waves are calculated accurately according to the fact that phase difference angles of twice FFT are zero, then a method for interpolating in a symmetrical window function frequency domain is used for calculating correction coefficients of the fundamental wave and the sub-harmonic waves, and finally amplitude values and phase positions of the sub power harmonic waves are calculated. The method for quickly calculating the power harmonic parameters in the high-accuracy mode has more obvious superiority than other windowing FFT interpolation correction analyzing methods in consumed calculation time, greatly decreases the calculated amount, is best for a digital signal processor (DSP) provided with FFT hardware and has practical value.