2337 results about "Negative voltage" patented technology

The invention discloses a SiC MOSFET gate oxide layer degradation monitoring method based on turn-off oscillation, and the method comprises the steps: measuring the drain-source current change rate diDS / dt when a SiC MOSFET is turned off through the source stray inductance voltage vcir, and carrying out the measurement of the gate oxide layer degradation of the SiC MOSFET based on the offset of the negative temperature sensitivity of the threshold voltage VTH in the diDS / dt and the positive temperature sensitivity of the electron mobility mu. Zero temperature sensitivity of a source stray inductance voltage negative peak value vcircmin is realized by adjusting a driving resistor RG and a negative voltage VEE during turn-off, and the gate oxide layer degradation degree of the SiC MOSFET is monitored under a selected monitoring driving resistor RGM and a turn-off gate voltage VEEM. The monitoring method is high in universality and has a good monitoring effect on degradation of gate oxide layers of SiC MOSFETs of different models; the temperature influence is extremely small, so that the device can work in an environment with large temperature fluctuation; a pin of a monitored device does not need to be used as a measurement interface, so that the system invasiveness is small; the parameter measurement methods are many and mature; and the method has great online application potential.

The invention discloses a phase change memory and electronic equipment, the phase change memory comprises a comparator, a second switch, a third switch, a memory circuit, a selected digital line, a first switch and an unselected digital line, the memory circuit, the selected digital line, the first switch and the unselected digital line are connected in sequence, and the reference voltage of the unselected digital line is set in a reading operation through the first switch and the third switch; the reference voltage is in positive correlation with the second negative voltage, the second negative voltage is smaller than the first negative voltage, and compared with the reference voltage which is in positive correlation with the first negative voltage, the lower reference voltage can be generated, so that the overshoot current flowing through the memory cell at the opening moment is reduced, and the reading interference suffered by the memory cell is reduced.

An electrical circuit includes positive and negative voltage rails, a reference voltage rail, a non-trimmable bandgap core configured to output a voltage reference on the reference voltage rail, and a trimming element in an auxiliary section located external to the bandgap core. A current source is coupled to the non-trimmable bandgap core and the positive voltage rail. An auxiliary diode arranged in an auxiliary section outside of the bandgap core is coupled to the current source and negative voltage rail. The trimming element is coupled to the current source external to the non-trimmable bandgap core and has an adjustable set point. The adjustable set point is adjusted to inject a corresponding bias current to the auxiliary section during a trimming process and thereby change the voltage reference.

The invention belongs to the field of driving circuits of gallium nitride (GaN) power devices in motor driving or power electronic conversion, and discloses a design method of a three-level active driving circuit for restraining bridge arm crosstalk of a GaN device, and the method comprises the steps that a circuit is connected in a bridge type topological structure, and the bridge type topological structure comprises an upper bridge arm and a lower bridge arm which are the same in structure; the upper bridge arm and the lower bridge arm are both divided into two parts, namely a traditional driving circuit and an auxiliary circuit, and the auxiliary circuit is divided into a negative voltage self-recovery circuit and a crosstalk suppression circuit. According to the invention, a negative voltage self-recovery circuit and a crosstalk suppression circuit are formed by using the output and reverse conduction characteristics of the charge pump and the auxiliary GaN device. The advantages of the two methods are combined, the defects of a traditional method are effectively overcome, the turn-off speed is increased, the turn-off loss is reduced, and the positive and negative crosstalk is reduced while the turn-on speed is hardly influenced and the reverse turn-on loss is not additionally increased. The overall design is flexible, efficient and reliable.

The embodiment of the invention provides a lithium-supplemented battery cell formation method and a lithium-supplemented battery cell, and relates to the technical field of batteries. The lithium supplement battery cell formation method comprises the following steps: carrying out constant-current charging on a lithium supplement battery cell under the conditions of a first current rate and a first negative voltage; under the condition of second current multiplying power and second negative voltage, performing constant-current charging on the lithium supplementing battery core to cut-off voltage; under the conditions of a third current rate and a third negative voltage, carrying out constant-current discharge on the lithium supplementing battery core; wherein the first negative pressure is larger than the second negative pressure, and the first negative pressure is smaller than the third negative pressure. And different negative pressure settings are adopted in different formation stages, so that the problems of lithium precipitation, black spots, bulging and the like on a battery cell interface can be improved, and the comprehensive performance of the battery cell is improved.

A method and apparatus for the electrochemical polishing of metallic workpieces are proposed, wherein an electrolyte medium containing solid granular particles and a liquid electrolyte is placed in a container and conductively connected to a first electrode, wherein the metallic workpiece is conductively connected to a second electrode and immersed in the electrolyte medium in the container, wherein the electrodes are subjected to an electrical voltage such that the first electrode in contact with the electrolyte medium has a negative voltage and the second electrode in contact with the workpiece has a positive voltage, and wherein the workpiece is moved relative to the majority of solid granular particles of the electrolyte medium in order to polish it electrochemically.The invention provides that the polarity of the electrical voltage applied to the electrodes is temporarily reversed at least once, in particular periodically, during the electrochemical polishing of the workpiece, so that the first electrode in contact with the electrolyte medium temporarily has a positive voltage and the second electrode in contact with the workpiece temporarily has a negative voltage.

A power converter system includes a DC voltage source, a control system, a multilevel inverter and a balancing circuit connected to the DC voltage source, and at least two DC link series connected capacitors connected between a positive and a negative voltage supply line (V+, V−) of the DC voltage source and having a mid-point therebetween. The balancing circuit comprises a plurality of switches that are connected in series between said positive and a negative voltage supply line (V+, V−), the plurality of switches arranged in a first pair of switches and a second pair of switches. A flying capacitor is connected between a mid point of the first pair of switches and a mid point of the second pair of switches, and an inductor is connected between said DC link capacitor mid point and a mid point between the first pair of switches and second pair of switches.

The utility model relates to the technical field of power electronics, in particular to a direct-current power supply input circuit and a battery management system, the direct-current power supply input circuit comprises an overvoltage detection unit, a driving unit, an anti-reverse connection unit and a soft start protection unit, and when a power supply voltage is greater than a first preset voltage, the overvoltage detection unit outputs a first control signal to the driving unit. The driving unit is switched on and outputs a second control signal when receiving the first control signal. The anti-reverse connection unit is conducted when the anode voltage of the power supply is greater than the cathode voltage of the power supply and the power supply voltage is greater than a second preset voltage, and is cut off when a second control signal is received. The soft start protection unit charges a capacitor in the soft start protection unit when the power supply is powered on, the soft start protection unit is switched on until the voltage of the capacitor is greater than a third preset voltage, and the soft start protection unit is switched off when a second control signal is received. And the functions of overvoltage protection, input power supply reverse connection protection and the like are considered in design, so that the reliability of system operation is improved.

The invention relates to a safe starting control method, device, equipment and medium for a bootstrap drive inverter, and the method comprises the steps: obtaining a detection voltage representing an output filter inductance voltage after responding to any starting event and before formally transmitting a drive signal; comparing the negative voltage with a preset negative voltage safety threshold value; only when the detected voltage is higher than the safety threshold, a driving enable signal is generated to allow the inverter to be normally started; otherwise, generating a driving blocking signal, carrying out detection and judgment again after waiting for preset time delay, and circulating the process until the system state enters the safe area; the method is realized by modifying a control algorithm, no power hardware needs to be added, the starting impact risk is eliminated with low cost, and the contradiction between the hardware limitation of a bootstrap drive circuit and the negative residual voltage possibly existing on the output inductance of the inverter is solved; therefore, the safety problem of direct connection between the impact current and the bridge arm during starting in an unfavorable initial state is solved.

The utility model provides an insulated gate bipolar transistor driving circuit with adjustable positive and negative voltages, comprising a magnetic isolation module, the input end of which is connected with a driving signal and outputs an isolation driving signal; the input end of the first voltage regulating module is connected with the first positive voltage and outputs a second positive voltage within a first preset range; the input end of the second voltage regulating module is connected with the first negative voltage and outputs a second negative voltage within a second preset range; the push-pull output module is connected between the second positive voltage and the second negative voltage, the control end of the push-pull output module is connected with an isolation driving signal, and the output end of the push-pull output module is connected with the gate pole of the to-be-tested insulated gate bipolar transistor through a gate resistor; and the protection module is controllably connected between the output end of the push-pull output module and the second voltage regulation module under the action of the control signal. The driving circuit has the beneficial effects that the positive and negative voltage output capability can be flexibly adjusted according to debugging requirements, the working condition requirements of different clients are met, and the flexibility and adaptability of the driving circuit are improved.

This power conversion device includes a multilevel inverter which outputs multilevel voltages by adding / subtracting voltage of a sub inverter to / from output voltage of a main inverter. The multilevel inverter can switch between PWM operation in which plural pulses are outputted in each of positive voltage output and negative voltage output in one cycle and a pulse width is controlled, and one-pulse operation in which one pulse is outputted in each of positive voltage output and negative voltage output in one cycle, and has a current-split switching mode in which current flowing between a neutral point and the sub inverter flows through a first switch group and a second switch group provided to the main inverter and connected in parallel, in a case where the main inverter outputs zero voltage which is the potential of the neutral point, in the one-pulse operation.

The present invention discloses a boost converter power stage circuit, comprising: an organic light-emitting diode power management integrated circuit unit, a switched capacitor converter, and a boost converter, wherein, a flying capacitor is used to boost the voltage of the inductor to twice the voltage, and then the positive voltage of the output voltage source is boosted, and then use the switched capacitor converter to output the voltage in order to obtain the conversion of the negative voltage.

A driver circuit for controlling a high-power switch. The driver circuit comprises a flyback converter having a positive output rail and a negative output. The driver circuit also comprises: a driving stage that is connected between the positive output rail and the negative output rail; a shunt regulator configured to regulate the negative output voltage on the negative output rail based on a difference between the negative output voltage and a target negative voltage value, wherein the shunt regulator is powered by the positive output voltage on the positive output rail; a short-circuit transistor having a conduction channel that is connected between the negative output rail and a ground terminal; and a regulation control circuit configured to: provide a short-circuit control signal to a control terminal of the short-circuit transistor in order to short the negative output rail to the ground terminal until the positive output voltage reaches a positive threshold.

In a plasma processing apparatus, a controller specifies a time point when a current starts to flow between an edge ring and a DC power supply after beginning an application of a negative DC voltage to the edge ring from the DC power supply. The controller specifies, from a voltage measurement value indicating a voltage of the edge ring at the time point, an estimate of a self-bias voltage of the edge ring generated by a supply of a radio frequency power. The controller sets a sum of an absolute value of the estimate of the self-bias voltage and a set value as an absolute value of the negative DC voltage to be applied to the edge ring by the DC power supply.

The invention discloses a partition display driving method, a display driving circuit and a display screen, and the method comprises the steps: obtaining the pixel ranges of a first display region and a second display region, and controlling the absolute value of a gate turn-off voltage received by a switching transistor in a pixel driving unit corresponding to the second display region to decrease according to the pixel range of the second display region; according to the pixel range of the first display area, the gate turn-on voltage received by the switch transistor in the pixel driving unit corresponding to the first display area is controlled to be reduced, so that when the display panel starts the partition refreshing function, differential processing can be performed on the positive voltage and the negative voltage of the gate of the switch transistor; and the purpose of reducing the brightness difference caused by the PBS or the NBS is achieved.

In the present invention, a first control circuit (11) turns on a first switching element (Q1) when a negative voltage is applied, and generates a first control signal for turning off the transistor (Q1) when a positive voltage is applied. A second control circuit (12) turns on a second switching element (Q2) when a negative voltage is applied, and generates a second control signal for turning off the transistor (Q2) when a positive voltage is applied. When a positive voltage is applied to the first switching element (Q1), the first control circuit (11) supplies the second control circuit (12) with power for generating the second control signal. When a positive voltage is applied to the second switching element (Q2), the second control circuit (12) supplies the first control circuit (11) with power for generating the first control signal.

Embodiments of the invention includes various power supplies for plasma systems. These power supplies, for example, closes a switch to connect and disconnect a current pathway to cause an application of an asymmetric periodic voltage waveform. Where each cycle of the asymmetric periodic voltage waveform includes a first portion that begins with a first negative voltage and changes to a positive peak voltage, a second portion that changes from the positive peak voltage to a third voltage level and a fourth portion that includes a negative voltage ramp from the third voltage level to a fourth voltage level.

A color electrophoretic display includes a light-transmissive electrode at a viewing surface, a back electrode, and an electrophoretic medium disposed therebetween. The electrophoretic medium includes a non-polar fluid and a multi-pigment particle system having four types of charged electrophoretic pigment particles in the fluid. The particles includes first, second, third, and fourth types of particles having different optical properties. The second, third, and fourth types of particles have a charge polarity opposite to the charge polarity of the first type of particle. The multi-pigment particle system is directly addressable with push-pull waveforms applied to the back electrode having voltage levels selected from a set of exactly four different voltage levels to render any of eight primary colors (red, green, blue, cyan, magenta, yellow, black, and white) at each pixel while holding the voltage on the light-transmissive electrode constant. The voltage levels comprise a first positive voltage, a second lower positive voltage, a near zero voltage, and a negative voltage.

Disclosed herein is a single photon avalanche diode (SPAD) pixel circuit, including a SPAD having an anode coupled to a negative voltage and a cathode and a cascode transistor having a drain coupled to the cathode of the SPAD, a gate controlled by a cascode control signal, and a source. A readout circuit is coupled to the source of the cascode transistor and configured to detect a voltage change at the source of the cascode transistor and generate a pulse indicating an occurrence of an avalanche event. An active quenching circuit is coupled to the cathode of the SPAD and configured to detect an onset of the avalanche event and pull the cathode of the SPAD to a negative voltage to quench the avalanche event.

The invention relates to an insulation detection method and related equipment thereof. The method comprises the following steps: according to the resistance values of a positive voltage sampling resistor R10, two positive detection resistors R13 and R14, a negative voltage sampling resistor R20 and two negative detection resistors R23 and R24, and a first voltage value Ux1, a second voltage value Uy1, a third voltage value Ux2 and a fourth voltage value Uy2, calculating the resistance values of the positive voltage sampling resistor R10, the two positive detection resistors R13 and R14, the negative voltage sampling resistor R20 and the two negative detection resistors R23 and R24; and calculating an insulation resistance value Rx of the DC bus positive electrode DC + to the protective grounding PE and an insulation resistance value Ry of the DC bus negative electrode DC-to the protective grounding PE. According to the invention, the problem of large insulation detection error in the prior art is solved, and the accuracy of insulation detection is improved.

The invention relates to a class-C voltage-controlled oscillator with negative-pressure substrate bias and a use method thereof. Aiming at the problem that a traditional C-type voltage-controlled oscillator is difficult to start, the C-type voltage-controlled oscillator provided by the scheme adopts different circuits to simultaneously control the grid voltage and the substrate voltage of the cross-coupled pair transistors, so that the transistors are effectively prevented from entering a linear region, and the C-type voltage-controlled oscillator is quickly started and stably works in a C-type oscillation mode. The circuit structure of the scheme comprises an NMOS (N-channel Metal Oxide Semiconductor) cross coupling circuit, a PMOS (P-channel Metal Oxide Semiconductor) cross coupling circuit, an LC resonant cavity circuit, an amplitude detection circuit, a Schmidt signal processing circuit and a negative voltage charge pump circuit. Wherein the Schmidt signal processing circuit and the negative voltage charge pump circuit rapidly process an initial oscillation signal and provide negative voltage required by the system, and a substrate of the NMOS cross coupling tube is biased. According to the scheme, the design structure is simple, the tuning range is wide, and a new thought is provided for research and design of quick start of the C-type voltage-controlled oscillator.

According to the pure hardware PID current control system and method based on the direct current brushless motor provided by the invention, the negative voltage interference generated by electromagnetic induction is directly filtered in the bus current signal acquisition stage through the cooperation of the current sampling module and the bus negative voltage elimination module; the problem of signal distortion caused by negative voltage in a traditional sampling circuit is eliminated, and the current effective value detection precision is improved; the PID control module constructed based on pure hardware calculates a difference value between a target voltage and an actual voltage in real time through an analog circuit, and generates a proportional, integral and differential composite compensation signal, so that a PWM modulation circuit can adjust duty ratio output in real time according to the compensation signal, and it is ensured that a bus current of a motor driver is rapidly converged to a target value; the whole scheme does not need to depend on a microcontroller and a complex software algorithm, closed-loop current control is achieved through discrete devices, and the system cost is reduced.

An enhancement mode gallium nitride (GaN) transistor configured to eliminate holes in the gate material under the gate metal. The transistor has four electrodes, namely a drain electrode, a source electrode, a gate electrode and a hole collector electrode. In a preferred embodiment, a negative voltage is applied to the hole collector electrode, attracting holes in the gate material under the gate metal. The attracted holes recombine with electrons supplied by the negative voltage, thereby substantially eliminating the holes.

The present invention proposes a sputtering cleaning system and cleaning method for the inner wall of the ionization chamber of a radio frequency ion thruster. The system is composed of a gas distributor, a potential control line, a radio frequency coil, an ionization chamber, a screen grid, an acceleration grid, a positive DC voltage source, a radio frequency power supply, a negative DC voltage source and a conductive tape. The method includes: 1. The radio frequency ion thruster is started, and plasma is formed in the ionization chamber; 2. A positive voltage is applied to the screen grid, and ions are drawn out by the grid system, and the thruster enters a working state; 3. When the conductive film is thicker and the power input is weakened, the positive DC power supply is turned off, and no ions are drawn out of the thruster; 4. The negative DC power supply is turned on, and a negative voltage is slowly applied to the potential control line to increase the energy of ions hitting the inner wall of the ionization chamber; 5. The conductive film on the inner wall of the ionization chamber is bombarded by ions, and particles are sputtered out. The particles are neutral and are discharged from the ionization chamber under the action of the neutral particle flow, thereby achieving cleaning of the inner wall of the ionization chamber.

The invention discloses a bit line voltage transmission circuit, which is characterized in that grid voltages of a first NMOS (N-channel Metal Oxide Semiconductor) tube and a PMOS (P-channel Metal Oxide Semiconductor) tube of a transmission gate between an IO (Input / Output) node and a bit line are respectively connected with a first control signal and a second control signal, and a pad electrode of the first PMOS tube is connected with a third control signal. When the first to third control signals are power supply voltage, first negative voltage and first positive voltage, the transmission gate is switched on. The first positive voltage is greater than or equal to the IO voltage and less than the power supply voltage, and is provided by the positive voltage signal generation circuit. The positive voltage signal generating circuit comprises a second NMOS tube, a third NMOS tube and a second PMOS tube. The grid electrode of the second NMOS tube and the drain electrode of the third NMOS tube are connected to a first node. The source electrode of the second NMOS tube and the grid electrode of the third NMOS tube are connected to a second node, and the second node serves as the output end of the first positive voltage. The source electrode of the third NMOS tube is connected with the source electrode of the second PMOS tube, and the drain electrode of the second PMOS tube is grounded. A first pull-up circuit is formed between the first node and the power supply voltage. The first pull-up circuit and the second PMOS tube are both controlled by a first enable signal.

The invention provides an extra-high voltage hybrid DC power transmission control system and method, and the system comprises a controller which is used for transmitting fault control trigger pulse control information to a hybrid converter when a transmitting end AC fault occurs; the hybrid converter is used for reducing the injected active power and the output direct-current power when the extra-high voltage direct-current power transmission line is in a normal operation condition; based on the state of the ultra-high-voltage direct-current power transmission line in the normal operation working condition, the full-bridge sub-module in the ultra-high-voltage direct-current power transmission line is controlled to output negative voltage, and short-circuit fault current is suppressed. And the turn-off current source type current converter is used for triggering an internal lightning arrester to generate a commutation voltage when a receiving end AC fault occurs, and carrying out commutation by combining the power grid voltage with the commutation voltage. According to the system, a hybrid converter is adopted at a sending end, active power and reactive power of the sending end are flexibly regulated and controlled, and negative voltage is output to suppress short-circuit fault current when a direct-current short-circuit fault occurs; and when the receiving end has an alternating current fault, reliable commutation can still be ensured.

The invention provides a range switching circuit, a current detection circuit and an alternating current measuring instrument, and relates to the technical field of electric measuring instruments. The range switching circuit comprises a current input port which comprises a positive terminal and a negative terminal; the current and voltage conversion unit comprises a plurality of range gating branches, each range gating branch comprises a primary coil, a dotted terminal of the primary coil is electrically connected with the positive terminal, and a synonym terminal of the primary coil is electrically connected with the negative terminal; the bidirectional voltage limiting circuit is connected in parallel with the current input port and comprises a positive voltage limiting circuit and a negative voltage limiting circuit which are connected in parallel; the input negative electrode of the compensation unit is electrically connected with the dotted terminal of the primary coil, and the input positive electrode and the output end of the compensation unit are electrically connected with the synonym terminal of the primary coil. According to the invention, the amplitude of current impact on the sampling resistor can be obviously reduced, the damage caused by inconsistent measuring range is avoided, and the overall reliability of the alternating current measuring instrument is improved.

The invention discloses a coaxial double-switch reluctance motor torque ripple minimization control method, which comprises the following steps: establishing a unified model for two switch reluctance motors, obtaining a reference torque through a proportional integral controller after making a difference between a reference rotating speed and an actual rotating speed, and establishing a phase current prediction model according to a phase voltage equation of the switch reluctance motors, based on the predicted current and the predicted angle, establishing a torque prediction model in a positive voltage excitation and zero voltage follow current mode in the conduction interval of each phase winding, and establishing a torque prediction model in a negative voltage demagnetization mode in the turn-off interval of each phase winding to obtain predicted torques of each phase winding in the conduction interval and the turn-off interval; and establishing a unified evaluation function by using the predicted torque and the reference torque of each phase winding of the two switched reluctance motors, and selecting an optimal switching state which enables the evaluation function to be minimum, thereby realizing the torque pulsation minimization control of the coaxial double-switched reluctance motor. The torque ripple minimization control method of the coaxial double-switch reluctance motor is not influenced by the phase difference of the double motors and the conduction range of each phase winding, can be easily expanded to a double-switch reluctance motor driving system with any phase number, and has good application prospect and engineering value.

The invention discloses a negative charge leakage circuit, a rapid chip negative charge leakage method and a radio frequency chip. The negative charge leakage circuit comprises a leakage circuit module and a control signal module, the bleeder circuit module comprises a first PMOS (P-channel Metal Oxide Semiconductor) tube, the source electrode of the first PMOS tube is grounded, and the drain electrode of the first PMOS tube is connected with the negative voltage potential of the chip; the input end of the control signal module is used for receiving an enable signal, and the output end of the control signal module is connected with the grid electrode of the first PMOS tube; the control signal module is used for outputting a corresponding control signal according to the received enable signal so as to control the first PMOS tube to be in a conduction state or a cut-off state; the first PMOS tube is used for discharging negative charges in the chip when the first PMOS tube is in a conducting state. According to the invention, the discharge speed of negative pressure in the chip can be improved, and the reliability of the chip in repeated power-on and power-off starting is improved.

The invention discloses a power supply device of a lighting system, which belongs to the field of regional lighting system design, and comprises a control module, an alternating current-direct current conversion module, a plurality of direct current-direct current conversion modules and a positive and negative voltage direct current bus, the control module is connected with the alternating current-direct current conversion module, and the input end of the alternating current-direct current conversion module is connected with three-phase alternating current; the output ends of the alternating current-direct current conversion modules are connected with the positive and negative voltage direct current bus, the positive and negative voltage direct current bus comprises a positive voltage terminal, a negative voltage terminal and a ground terminal, the input end of each direct current-direct current conversion module is connected with the positive voltage terminal and the negative voltage terminal, and the shell of each direct current-direct current conversion module is connected with the ground terminal. An output mode of the positive and negative voltage direct current bus is adopted, the insulation grade of an output direct current cable can be reduced by half, regional installation and implementation are achieved, cost is low, regional targeted construction is achieved, flexibility and convenience are achieved, and follow-up upgrading and maintenance are easy.