266 results about "Shunt capacitors" patented technology

The ramp up time of a change pump is decreased by providing shunt capacitors connecting nodes of the serially connected stages to the output terminal of the charge pump, thereby reducing the impedance of the charge pump and decreasing ramp up time.

The invention relates to LED replacement lamp suitable for operation with a high frequency fluorescent lamp ballast, comprising—a LED load (LS) comprising a series arrangement of LEDs,—a first lamp end circuit comprising—a first lamp pin (LP1) and a second lamp pin (LP2) for connection to a first lamp connection terminal comprised in the high frequency fluorescent lamp ballast,—a first rectifier (D1-D4; D1,D2) equipped with at least one input terminal coupled to the second lamp pin and with first and second output terminals coupled to respective ends of the LED load, the first rectifier comprising at least two diodes, one of which is shunted by a first capacitor (C1),—a second lamp end circuit comprising—a third lamp pin (LP3) and a fourth lamp pin (LP4) for connection to a second lamp connection terminal comprised in the high frequency fluorescent lamp ballast,—a second rectifier (D5-D8, D5, D6) equipped with at least one input terminal coupled to the fourth lamp pin and with first and second output terminals coupled to respective ends of the LED load, the second rectifier comprising at least two diodes, one of which is shunted by a second capacitor (C2), wherein the first capacitor and the second capacitor form a series arrangement coupled between the second lamp pin and the fourth lamp pin.

Provided is a digital duty cycle correction circuit and method for a multi-phase clock, in which duty cycle correction information of an input clock signal is stored in a power save state of a system by adopting a digital correction method in a duty cycle correction method for a multi-phase clock and phase information of the input clock signal is held constant during duty cycle correction of the input clock signal by correcting duty cycles of the input clock signal by changing the falling edge of the clock without changing the rising edge of the input clock signal during duty cycle correction of the input clock signal, thereby correcting the multi-phase clock. To this end, the digital duty cycle correction circuit includes a clock delay means that takes the form of a shunt capacitor-inverter, a clock generation means including a clock rising edge generation circuit and a clock falling edge generation circuit, and a digital duty cycle detection means including integrators, a comparator, and a counter/register.

A capacitive detection device (20) for a vehicle comprises a sensing electrode (26) for generating an oscillatory electric field in a detection space and a shielding electrode (28) arranged on a side of the sensing electrode turned away from the detection space. The capacitive detection device comprises a circuit ground and a ground connector for connecting the circuit ground to chassis ground of the vehicle. At least one shunt capacitor is connected between circuit ground and the shielding electrode. The at least one shunt capacitor has a capacitance at least 25 times higher than the capacitance between the shielding electrode and the chassis ground of the vehicle.

A Class-E amplifier has bee adapted for use in the radio frequency section of a magnetic resonance imaging (MRI) system. A drive signal is produces by modulating the envelope of a radio frequency carrier signal and then applied to a switch in the Class-E amplifier. The switch is connected in series with a choke between a supply voltage terminal and circuit ground with an output node formed between the choke and the switch. The output node is coupled to circuit ground by a shunt capacitor. In a preferred embodiment, a pair of such amplifiers, that are Π radians out of phase, are connected to each rung of a transverse electromagnetic transmit array type radio frequency coil of the MRI system.

First and second through-side field effect transistors are connected between first and second high frequency signal input/output terminals, and an antenna, respectively. The first and the second high frequency signal input/output terminals are connected with one end of the first and the second shunt-side field effect transistors, respectively. A series resonant circuit including a shunt capacitor and a bonding wire is connected between the other end of the first and the second shunt-side field effect transistors, and a ground.

An apparatus and method is provided for identifying a faulted phase in at least one shunt capacitor bank. The apparatus generally includes a sampling circuit for sampling current or voltage signals associated with the shunt capacitor bank. A microcontroller is coupled to the sampling circuit and programmed to measure a compensated neutral point phase angle from the sampled signal, and compare the compensated neutral point phase angle with a fixed reference phase angle to identify the faulted phase of the shunt capacitor bank. The method generally includes the steps of sampling a current or voltage signal associated with the shunt capacitor bank, determining a compensated neutral point phase angle from the sampled signal, and comparing the compensated neutral point phase angle with a fixed reference phase angle to identify the faulted phase of the shunt capacitor bank. The invention also relates to an apparatus and method for identifying the location of the fault (e.g., the section of the bank) in a double ungrounded shunt capacitor bank or double WYE shunt capacitor bank.

A method for adjusting a qubit includes measuring a qubit characteristic of a qubit device and computing a modification to correct the qubit characteristic. A geometry of a shunt capacitor is adjusted using a laser direct write process. The qubit characteristic is verified.

The invention discloses a voltage stability assessment method for a multi-infeed AC/DC hybrid power system. On the basis of a multi-infeed effective short circuit ratio considering shunt capacitor compensation, a reactive power conversion factor is adopted for describing an influence degree on voltage of a DC system by a shunt capacitor compensation point in an AC system, a conversion method is adopted for acquiring reactive power influence quantity on the DC system by a shunt capacitor connected with each compensation point in the AC system, reactive power influence quantities on the DC system by all shunt capacitor compensation points in the system are accumulated, and bad influences on voltage stability of the DC system by whole system shunt compensation are acquired. According to the whole system reactive power influence quantities, the effective short circuit ratio is acquired, influences included in shunt capacitor compensation are further acquired, and stability of the power system is assessed according to the effective short circuit ratio. Compared with the current AC/DC hybrid power system voltage stability assessment method on the basis of the multi-infeed effective short circuit ratio, the method provided by the invention has high accuracy, and provides a basis for planning and operation of a multi-DC infeed power grid system.

An electro-mechanical harmonic load pull tuner uses three variable and adjustable shunt air capacitors and three variable and adjustable series phase shifters and creates independently controllable impedances at three harmonic frequencies in the frequency range between 30 and 250 MHz. Independent harmonic tuning is possible because the combination of adjustable shunt capacitors and series phase shifters allows generating more than 10¹⁹ impedance states at each frequency covering the entire Smith chart; appropriate impedance-search Error Function-based optimization algorithms allow fast harmonic tuning for impedance tuning and matching the output of RF transistors and amplifiers at the fundamental and harmonic frequencies. Stepper motors, drivers and control software are used to automate, calibrate and use the harmonic tuner in an automated harmonic load pull measuring setup.

An active clamping high-gain alternate parallel voltage boosting convertor disclosed by the invention comprises two power switching diodes, two output diodes, two clamping diodes, two auxiliary power switching diodes, two clamping capacitors, two switching capacitors, an output capacitor and two coupling inductors. Two coupling inductors respectively comprise two windings. The present invention uses the second winding of two coupling inductors and two switching capacitors to realize the high-gain output of the convertor. With the leakage inductance of two coupling inductors, two clamping capacitors, the shunt capacitor existing in two power switching diodes themselves and the gate arrangement of two power switching diodes and two auxiliary power switching diodes, the zero voltage switching-on and zero voltage switching-off of two power switching diodes and two clamping diodes are realized. The soft switching-off of two output diodes and two clamping diodes are realized with the leakage inductance of two coupling inductors, and the circuit does not include energy losing element and the output gain of the convertor and the circuit efficiency can be increased.

A closed conductive loop for use in planar circuits to realize shunt capacitors instead of conductive patches is disclosed. The closed conductive loop may be formed on a planar substrate or extend to multiple conductive layers in a multi-layer circuit. The use of closed conductive loops as shunt capacitors offers possibilities of more flexible circuit layout, reduced circuit footprint and comparable or improved performance as compared to using conductive patches as shunt capacitors.

A novel dynamic voltage sharing device for a serially connected super capacitor banks comprises two parts including a hardware circuit and a controller, wherein the hardware circuit comprises a shunt capacitor Cb generating balanced current, a switch network, the super capacitor bank and a voltage measuring unit, the switch network comprises switches S1, S2, S3, S4, ..., S2n-1 and S2n, the super capacitor bank comprises super capacitors C1, C2, ..., Cn, the n is a natural number, and the voltage measuring unit comprises voltage measuring devices, and the number of the voltage measuring devices corresponds to the number of the super capacitors. Each group of the switches S2n-1 and S2n corresponds to the super capacitor Cn and the corresponding voltage measuring device thereof. Two poles of the shunt capacitor Cb are respectively connected two poles of the super capacitor Cn via the S2n-1 and S2n. The voltage UCn applied to the two ends of the super capacitor is measured by the corresponding voltage measuring device, and then measured result is transmitted to the controller. The controller outputs switch controlling signals to control switching conditions of the switches in the switch network.

An automatic multi frequency-range electro-mechanical impedance tuner covers frequencies from a low megahertz to a high gigahertz range, by combining a high frequency with one or two a low frequency tuner modules; the low frequency module is made using either variable phase shifter-capacitor or multi-capacitor-transmission line tuner structures. The high frequency module is a single, double or triple probe slide screw tuner covering up to 1.5 decades in frequency; the low frequency tuner is using cascades of three or more capacitor-coax cable tuning sections or a low frequency phase shifter combined with a variable shunt capacitor; the low frequency tuner can operate as low as a few megahertz whereas the high frequency tuner can operate up to several gigahertz. Depending on the application, low frequency parallel-blade capacitors or high frequency coaxial trimmers are used. Typical cross-over frequencies between low and high frequency modules range from 200 to 800 megahertz, lowest frequencies can reach below 10 megahertz and highest frequencies 26 to 40 gigahertz. Appropriate calibration, control and tuning procedures allow for a fully integrated operation.

The invention relates to a multilevel active power filter based on LCL filtering. The multilevel active power filter comprises a two-level three-phase four-bridge arm current transformer, a three-phase LCL output filter and a shunt capacitor. The output end of the three-phase LCL output filter is connected with a three-phase power grid, the input end of the three-phase LCL output filter is connected with a bridge arm port of the three-phase four-bridge arm current transformer, a zero-sequence bridge arm of the three-phase four-bridge arm current transformer is connected with a three-phase power grid null line through a filter inductor, and direct current bus sections of all sets of current transformer bodies of the three-phase four-bridge arm current transformer are respectively connected with the two ends of the capacitor. By the adoption of the multilevel active power filter, the problem of harmonic wave and three-phase imbalance in a three-phase four-wire system is solved.

The invention discloses an on-line monitoring system and method of a 35kV high-voltage shunt capacitor. The on-line monitoring system of the 35kV high-voltage shunt capacitor mainly comprises a data collecting module, a data transmitting module, a data analyzing module, a display module and a power source supply module, wherein the data collecting module and the power source supply module are located at a high-voltage side of a transformer substation and are respectively used for collecting the running parameters of the capacitor and supplying power to the data collecting module, the data transmitting module achieves optical fiber transmission of data between the high-voltage side and a low-voltage side, and the data analyzing module and the display module are located in an industrial control computer at the low-voltage side and are respectively used for further analyzing the obtained data and storing, outputting and displaying the analysis result. The on-line monitoring system of the 35kV high-voltage shunt capacitor achieves transverse comparison of effective values of current and temperature and longitudinal comparison of capacitance values, and effectively avoids the defect that an existing single-parameter monitoring system is high in missing-judgment rate and false-judgment rate. Meanwhile, FFT conversion of self-adaptive windowing and interpolation is adopted, the accuracy of the harmonic wave analysis is improved, and on-line state monitoring and fault diagnosis on the high-voltage shunt capacitor are facilitated.

A wideband harmonic trap includes a first resonant tank in the form of a parallel LC circuit, and a second resonant tank in the form of a series LC circuit. The LC circuits are connected to it common input, an output of the parallel LC circuit is connected to a load and to ground via a shunt capacitor, and an output of the series LC circuit is connected to the ground.

The invention discloses a miniature LTCC 1.8-GHz power divider with a built-in resistor. The miniature LTCC 1.8-GHz power divider with the built-in resistor comprises a surface-mounted 50-ohm impedance input port, an input inductor, a first spiral inductor, a second spiral inductor, a ground capacitor, a shunt capacitor, two vertical ports, two first parallel ports, two second parallel ports, the built-in tantalum absorption resistor, a first output inductor, a second output inductor, a first surface-mounted 50-ohm impedance output port, a second surface-mounted 50-ohm impedance output port and a ground plate. The miniature LTCC 1.8-GHz power divider is made of LTCC materials in a three-dimensional integrated mode and has the advantages that use is easy and convenient, the size is small, the isolation degree is high, the insertion loss is low, the phase difference between the two output ports is small, the reliability is high, the electrical performance and the temperature stability are good, the cost is low, and mass production can be achieved.