880 results about "Limiting current" patented technology

Systems, methods, and apparatus for providing power to an electrosurgical instrument. In particular, a power supply is disclosed in which non-sinusoidal (e.g., pulsed) constant frequency voltage having a variable amplitude is passed to an LC circuit to produce a quasi-sinusoidal current in the LC circuit. The constant driving frequency can be one half the resonant frequency of the LC circuit allowing the LC circuit to operate as an impedance, and thus limit current spikes and arcing. The frequency and phasing of the driving voltage also enables the LC circuit to discharge energy back into a power provider of the power supply so that energy does not build up in the LC circuit. These features result in less severe current spikes and arcing, as well as reduced cutoff times.

The present invention takes the form of a current limiting apparatus and method for limiting current flow, induced when the level of an external signal is greater than an external signal threshold signal level, in a conductive loop formed by a medical device implanted within a living organism having electrically excitable tissue. The system includes an implantable pulse generator (IPG) system having a housing, a signal generator disposed in the housing that generates an electrical signal, and at least one lead extending from the housing to convey electrical signal to the patient. To limit the induced current flow, the IPG includes current limiting componentry, an impedance increasing element, and / or alternating current blocking elements. These components provide an alternating current impedance path to the electrical ground from a lead coupled to the capacitive element. Also disclosed are techniques for reducing the effective surface area of the current inducing loop caused by the IPG system.

Vehicle operation (e.g., speed, acceleration) may be limited based on various conditions such as a current charge condition of an electrical energy storage devices (e.g., batteries, super- or ultracapacitors), history of such, conditions related to the vehicle (e.g., mileage, weight, size, drag coefficient), a driver or operator of the vehicle (e.g., history with respect to speed, acceleration, mileage) and / or environmental conditions (e.g., ambient temperature, terrain). A controller may control operation of one or more power converters to limit current and / or voltage supplied to a traction electric motor, accordingly.

A memory cell is described, the memory cell comprising a dielectric rupture antifuse and a layer of a resistivity-switching material arranged electrically in series, wherein the resistivity-switching material is a metal oxide or nitride compound, the compound including exactly one metal. The dielectric rupture antifuse is ruptured in a preconditioning step, forming a rupture region through the antifuse. The rupture region provides a narrow conductive path, serving to limit current to the resistivity-switching material, and improving control when the resistivity-switching layer is switched between higher-and lower-resistivity states.

A plug and / or a plug and cord connector set that is easily mass produced and includes integrated circuitry for use with decorative lighting products such as Christmas lights and rope lights. The integrated circuitry included in the plug and / or plug and cord connector combination can serve to reduce or limit current, provide full-wave AC to DC rectification, provide overload protection, reduce voltage, protect against voltage spikes, add blinking or flashing functions, or any combination thereof. An optional intermediate circuit is included for the manufacture of light strings employing multiple series connections.

A protection circuit for use with a charger and a chargeable element, such as a rechargeable lithium ion battery, comprises a shunt regulator having a threshold ON voltage coupled in parallel across the chargeable element, and a temperature-dependent resistor, e.g., a positive temperature coefficient device, coupled in series between the charger and the chargeable element. The temperature dependent resistor is thermally and electrically coupled to the shunt regulator, wherein the first variable resistor limits current flowing through the shunt regulator if the current reaches a predetermined level less than that which would cause failure of the regulator, due to ohmic heating of the regulator.

A protection circuit for use with a charger and a chargeable element, such as a rechargeable lithium ion battery, comprises a shunt regulator having a threshold ON voltage coupled in parallel across the chargeable element, and a temperature-dependent resistor, e.g., a positive temperature coefficient device, coupled in series between the charger and the chargeable element. The temperature dependent resistor is thermally and electrically coupled to the shunt regulator, wherein the first variable resistor limits current flowing through the shunt regulator if the current reaches a predetermined level less than that which would cause failure of the regulator, due to ohmic heating of the regulator.

An imaging apparatus includes a semiconductor light-emitting device functioning as a strobe light having a current limitation unit for limiting current to flow to the semiconductor light-emitting device. The current limitation unit limits current to flow to the semiconductor light-emitting device under a predetermined condition for increasing a current consumption amount.

The invention relates to a modified lithium-based composite negative material for a solid state battery and preparation and application of the material. The modified lithium-based composite negative material comprises 50-95 parts of lithium and 5-50 parts of a modified additive by weight; and the modified additive comprises one or multiple nitride or fluoride. The preparation method comprises thatthe lithium and modified additive are mixed, heated to 180-400 DEG C, stirred uniformly, and cooled to the room temperature; and the modified composite negative material is used to the solid state battery, and combined with a solid electrolyte. Compared with the prior art, the lithium metal is mixed with the modified additive by mixing in a heating fusing way, the surface energy of the lithium metal can be reduced effectively, elements including nitrogen and fluorine are introduced in a controllable way, the interfacial resistance between the solid electrolyte and lithium cathode is reduced effectively, the limit current that can be born by the solid electrolyte is increased, the recyclable charge and discharge capacity is improved, and the solid electrolyte and cathode interface is stable for a longer time in the long circulation process.

In a switching mode power supply, an input received from the secondary side of the transformer 7 and indicative of the power being drawn by the loads is used to control the timing of bursts. The input is compared with two threshold different threshold values V2, V3, and switching is enabled if the input rises above a first higher threshold value V2, and disabled if it falls below a second lower threshold value V3. A memory device FF1 controls a current limitation circuit which limits currents in the primary of the transformer when the switching mode power supply is operating in the burst mode.

An intracellular electro-manipulation apparatus for delivery an electric field pulse to a target of one or more biological cells is provided. The apparatus includes a pulse generator that generates an ultrashort electric field pulse, and a pulse delivery system that directs the ultrashort electric field pulse to the target. The apparatus can include a reflected-signal impeder connected between the pulse generator and the pulse delivery system to impede reflection of a signal to the pulse generator when impedance mismatching between the pulse delivery system and pulse generator occurs. Alternatively, or additionally, the apparatus can include a current limiter connected between the pulse generator and the pulse delivery system to limit current between the pulse generator and the pulse delivery system when a high-conductivity condition occurs in the target.

In structure of electrode, catalysis layer is in structure of multiple layers. The said catalysis layer composed of composite two layers including hydrophilic catalysis layer and hydrophobic catalysis layer covering on surface of membrane. Catalysis layer composed of composite two layers is fabricated through steps: catalyst and Nation are dispersed on membrane directly or dispersed on membrane through transferring press of polytetrafluoroethylene (PTFE) film indirectly. Advantages are: in favor of discharging CO2 from anode and O2 from cathode, reducing loss caused by polarization of mass transfer, increasing ultimate current density so as to raise performance of electrode and use ratio of catalyst prepared from noble metal.

A controller (44) for a SMA actuator (2) includes an electgric power source (46) for applying an electric current through an SMA element (8), a sensor (48) to detect change in an electric resistance of the element (8); and a regulator (50) for controlling the magnitude of the applied electric current. The regulator (50) applies a first current above a safe limit current for the element (8) until a selected change in the electric resistance is detected and applies a second current less than the first current after the change is detected.

A method of limiting current in a DC motor acts on a full bridge circuit (137) through which the stator winding arrangement (102) of that motor is supplied with current. Upon response of the current limiter, energy supply to the stator winding arrangement (102) from the DC power network is interrupted. The stator winding arrangement is then operated substantially in short circuit via semiconductor switches of the full bridge circuit, and the decaying current flowing in that context serves substantially to continue driving the motor. When that current has reached a lower value, energy supply from the DC power network to the motor is once again activated. The effective value of the current flowing to the motor is preferably reduced when the current limiter responds. The time period during which that current flows, in the form of current blocks, is then increased in compensatory fashion.

When a battery current is not larger than a limit current set depending on the battery temperature and is flowing continuously for a predetermined time set depending on the battery temperature or longer, a decision is made that a secondary battery is in stable state. When the secondary battery is in stabilized state, the battery voltage is considered to be equal to the open circuit voltage and SOC estimation is performed based on the open circuit voltage-SOC characteristics. When the product of the internal resistance of the secondary battery and the limit current is made substantially constant (constant voltage) by setting the limit current in association with temperature dependence of the internal resistance, estimation error can be kept within a predetermined range in the stabilized state even if SOC estimation is performed while the battery voltage is assumed as the open circuit voltage. Consequently, SOC can be estimated with high precision within a predetermined error by a simple and reliable system under stabilized state.

Periodic biological functions and their related anatomy that cannot be seen in image sequences using typical means, can nonetheless be made visible by demodulating the image sequence according to the timing of that biological function using the described method. In particular, vascular structure and the function of that structure becomes observable when demodulated according to the patient's heart beat. This method suppresses the effects of thermal variations across the anatomy, and of severe scattering loss from buried tissues, that limit current thermographic (heat imaging) methods. It also measures localized changes in the wave front amplitude, shape, and phase, which are expected to prove useful for disease diagnosis and biometry.

According to a first aspect, a power supply and a method of providing power for igniting a plasma in a reactive gas generator is provided that includes (i) coupling a series resonant circuit that comprises a resonant inductor and a resonant capacitor between a switching power source and a transformer, the transformer having a transformer primary and a plasma secondary; (ii) providing a substantially resonant AC voltage from the resonant capacitor across the transformer primary, thereby inducing a substantially resonant current within the transformer primary to generate the plasma secondary; and (iii) upon generation of the plasma secondary, the resonant inductor limiting current flowing to the switching power supply. According to another aspect, bipolar high voltage ignition electrodes can be used in conjunction with inductive energy coupling to aid in plasma ignition.

The invention provides a cable semi-conductive shielding material which belongs to the field of electric cable fabrication technique and a preparation method thereof, and the components of the material and the content thereof are as follows: ethylene-vinyl acetate copolymer or linear low density polyethylene 100 proportion by weight, black carbon 10-50 proportion by weight, anti-oxidant 0.1-5 proportion by weight as well as cross linker 0.1-5 proportion by weight. The method provided by the invention can effectively inhibit accumulation of space charges in insulation material, and improves electric field threshold value of injected space charge, which reduces insulation material electric conductivity increased effect induced by space charge-limited current (SCLC), and the electric field distortion rate in XLPE is only 14-19% under -60kV / mm extra electric field for 60 minutes.

A circuit breaker includes current detectors, a microprocessor-controlled tripping device, and a bypass circuit that interacts with a watchdog circuit that monitors the proper functioning of the microprocessor. A switchable reference voltage is made available to the bypass circuit as a function of the momentary supply voltage. During short circuits, the bypass circuit, immediately upon being switched on, responds to very high limit current values, whereas after the switch-on phase, it already responds at moderately high limit current values.

A current limit circuit regulates the current flow through a power switch 90 by measuring the current through the switch 90 and comparing it to a reference voltage VREF that represents the limit current. When the current through the power switch 90 is greater than the limit current, the current in the power switch 90 is pulled lower by a driver circuit 92 which controls the power switch 90. By using a current limit reference voltage that has two levels, the power switch 90 has two current limit thresholds. Using a comparator 94 to compare the input voltage of the power switch 90 to the output voltage of the power switch 90, an output signal is generated to control the current limit threshold. When the input voltage and output voltage has a large differential voltage, a lower current limit threshold voltage is selected. When the input voltage and output voltage has a small differential voltage, an upper limit threshold voltage is selected.

This inventive high power diode laser driver is used for driving high power diode laser or diode laser array and providing complete protective units, with its kernel part of voltage controlled current source. The circuit board of the voltage controlled current source consistes of: a voltage reference circuit (1), current-limiting circuit (2), soft starting circuit (3), anti-surge circuit (4), modulation input circuit (5), feed-back control circuit (6) and current driving circuit (7). This inventive negative feedback principle stable output current can provide: constant current driving mode (CCD mode) and constant power driving mode (CPD mode), which CCD mode can preset precisely the working current and limiting current of LD with long duration stability of 38ppm, and which CPD mode can automatically regulate output current to ensure constant power working of LD, and said (2) and (3) provides safety driving of LD.

A semiconductor device includes an IGBT, a constant voltage circuit, and protection Zener diodes. The IGBT makes / breaks a low-voltage current flowing in a primary coil. The constant voltage circuit and the protection Zener diodes are provided between an external gate terminal and an external collector terminal. The constant voltage circuit supplies a constant gate voltage to the IGBT to thereby set a saturation current value of the IGBT to a predetermined limiting current value. The IGBT has the saturation current value in a limiting current value range of the semiconductor device.

A charging circuit includes a main control microchip, a charging integrated circuit, and a current control circuit. The main control microchip includes a power-on pin connected to a charging device. The charging integrated circuit comprises a power input pin and a current limit pin, wherein the power input pin is connected to the charging device, and the charging integrated circuit is capable of limiting current. The current control circuit comprises a transistor, a first current limiting resistor and a second current limiting resistor, a base of the transistor is connected to the main control microchip, the first current limiting resistor is connected between the current limit pin and ground, and the second current limiting resistor is connected between the current limit pin and a collector of the transistor, the main control microchip is operable to output control signals to enable or disable the transistor.

A four switch voltage converter is regulated for buck mode and boost mode under constant frequency valley-peak current mode control. Protection circuits are responsive to output voltage and regulator current to prevent excessive current that otherwise might result from abnormally low output voltage short circuit, or spurious switching abnormalities during low duty cycle operation. The regulator control circuit is responsive to the protection circuits to automatically connect a regulator inductor between a common potential and the output to limit current.

Systems, methods, and apparatus for providing power to an electrosurgical instrument. In particular, a power supply is disclosed in which non-sinusoidal (e.g., pulsed) constant frequency voltage having a variable amplitude is passed to an LC circuit to produce a quasi-sinusoidal current in the LC circuit. The constant driving frequency can be one half the resonant frequency of the LC circuit allowing the LC circuit to operate as an impedance, and thus limit current spikes and arcing. The frequency and phasing of the driving voltage also enables the LC circuit to discharge energy back into a power provider of the power supply so that energy does not build up in the LC circuit. These features result in less severe current spikes and arcing, as well as reduced cutoff times.

An electrical switch for connecting and breaking a circuit including a connecting and breaking mechanism for connecting and breaking the circuit provided with at least a set of movable contacts and stationary contacts; a electromagnetism drive mechanism for controlling the contacts to be actuated so as to realize closed circuit; a housing for accommodating the movable contact and stationary contact; an arc-extinguishing mechanism disposed in the housing and corresponded to the movable and stationary contact; a case connected to a base for accommodating the electromagnetism drive mechanism; a bedplate associated with the case; and a holding mechanism disposed on the bedplate for holding the contacts to connect the circuit, the electromagnetic holding mechanism is electromagnetic and has a set of electromagnetic attracting mechanism in which the movable iron core is made to be a pothook or a baffle mechanism, the movable iron core is attracted so that the pothook or baffle keeps the switch closed by means of hitching or ramming the movable bolt when the electromagnetic attracting mechanism is powered on. The electrical switch has a structure in which it has a breakaway mechanism using winding, in which the remanence being small and the feedback force being large and the action of the limiting current being rapid, it can break the large short current as air switch.