281results about How to "Reduce ripple" patented technology

A power control circuit is provided containing a switch array, which includes segmented switches, a flying capacitor, an output voltage terminal, a feedback loop, and a digital voltage regulator block. The digital voltage regulator block includes an A / D converter, an encoder, an add-subtractor, and a gate logic. These power control circuits do not include pass transistors. A method is also provided, where the charge pumps of the power control circuit are operated in two-phase cycles including a charging phase and a pumping phase. The power control circuit is controlled in both of these phases, thereby reducing the ripple of the output voltage.

We describe a photovoltaic (PV) panel system comprising a PV panel with multiple sub-strings of connected solar cells in combination with a power conditioning unit (microinverter). The power conditioning unit comprises a set of input power converters, one connected to each sub-string, and a common output power conversion stage, to provide power to an ac mains power supply output. Integration of the micro-inverter into the solar PV module in this way provides many advantages, including greater efficiency and reliability. Additionally, embodiments of the invention avoid the need for bypass diodes, a component with a high failure rate in PV panels, providing lower power loss and higher reliability.

In a pulse frequency modulated (PFM) voltage regulator, a PFM switching controller is provided to generate a PFM switching signal for converting a DC voltage source to an output voltage. A minimum OFF-time controller provides the PFM switching signal with a minimum OFF-time. In response to the output voltage, a feedback circuit generates a feedback signal. When the output voltage is lower than a predetermined target voltage, an OFF-time prolonging circuit prolongs the minimum OFF-time in response to the feedback signal. In other words, a time of delivering energy to a capacitor from an inductor may be prolonged by the OFF-time prolonging circuit. Therefore, a ripple of the output voltage is effectively reduced when the PFM voltage regulator is operated in a heavy loading condition.

A switching power supply circuit in which a series circuit comprising a resistive element and a capacitive element is provided in a parallel configuration with an inductor which supplies a load current to a load circuit, a voltage comparator having first and second threshold voltages discriminates a voltage obtained from a mutual connecting point of the series circuit therefrom and controls a switch element for supplying a current to the inductor, thereby varying the current supplied to the inductor in accordance with a variation in the load current is combined with a series power supply circuit which shares the load current of the load circuit.

An axial gap dynamoelectric machine comprises first and second stators disposed coaxially with an intermediate rotor. The stators are selectively aligned with an axial offset between the positions of their respective teeth and slots. The stators comprise toroidal cores having laminated layers composed of a material selected from the group consisting of amorphous and nanocrystalline metals and optimized Fe-based alloy. Optionally, the machine further comprises misalignment means for adjusting the offset of the stators. Adaptive adjustment permits the machine to be operated to in a mode that reduces the back EMF of the motor, allowing constant voltage to be maintained as speed is increased. Reducing back EMF also allows a wider range of operating speed, especially in combination with use of high pole counts. Alternatively, the machine can be operated, e.g. at lower speed, in a constant torque mode. The machine may exploit the high pole count achievable by use of improved soft magnetic materials. Also provided are techniques for reducing torque ripple during operation, and also for using the stator offset in combination with a dual full wave bridge rectifier arrangement.

The objective of this invention is to reduce the current flowing through the inductance element in a step-up / step-down DC—DC converter and to control the ripple in the output voltage. In the DC—DC converter, four states, that is, the first state [1] of (M1, M2)=(off, on) and (M3, M4)=(on, off), the second state [2] of (M1, M2)=(on, off) and (M3, M4)=(off, on), the third state [3] of (M1, M2)=(on, off) and (M3, M4)=(on, off), and the fourth state [4] of (M1, M2)=(off, on) and (M3, M4)=(off, on) are repeated in a prescribed order, preferably in the order . . . [1]→[4]→[2]→[3]→[1] . . . or . . . [1]→[3]→[2]→[4]→[1] . . . .

A gate drive circuit includes a shift register having stages connected to each other in series. An (m)-th stage (‘m’ is a natural number) includes an output part, a discharging part, a first holding part and a second holding part. The output part outputs the first clock signal as a gate signal in response to a first clock signal provided from an external device and discharges the gate signal in response to a second input signal. The output part includes a first transistor having a first channel length. The discharging part discharges a signal of the first node to the second voltage level. The first holding part maintains a signal of the first node at a level of the gate signal, and is discharged to the second voltage level. The first holding part includes a second transistor having a second channel length that is longer than the first channel length. The second holding part maintains a signal of the first node at a level of the second voltage level.

The present invention relates to a driver for a string (STi) of series arranged light emitting diodes (D1i, D2i, D3i) of which at least two emit light having different spectra. The driver comprises a main power supply (PAi) which has outputs coupled across the string (STi) to supply a main current (IAi) to the string (STi). A secondary power supply (PBi) is coupled to at least one of junctions (J1i) between successive light emitting diodes (D1i, D2i) in the string (STi) to supply or withdraw a delta current (IBi) from the junction (J1i). The delta current (IBi) is at least a factor 5 smaller than the main current (IAi). A controller (CO) controls the secondary power supply (PBi) to generate the delta current (IBi) to obtain a desired spectral composition of the mixed light emitted by the string (STi).

A switching power supply circuit in which a series circuit comprising a resistive element and a capacitive element is provided in a parallel configuration with an inductor which supplies a load current to a load circuit, a voltage comparator having first and second threshold voltages discriminates a voltage obtained from a mutual connecting point of the series circuit therefrom and controls a switch element for supplying a current to the inductor, thereby varying the current supplied to the inductor in accordance with a variation in the load current is combined with a series power supply circuit which shares the load current of the load circuit.

In a ladder type filter, a first inductor is connected in series with a parallel resonator. A second inductor is connected in parallel to a series resonator. The resonant point of the parallel resonator having the first inductor connected in series and the anti-resonant point of the series resonator developed on the lower frequency side of the resonant point of the series resonator, caused by the second inductor connected in parallel, substantially coincide with each other.

In a gate driving circuit and a display apparatus, the gate driving circuit comprises a plurality of stages. At least one of the stages comprises a pull-up section responsive to a first node signal; a pull-down section responsive to a second input signal; a discharging section discharging the first node signal in response to the second input signal; a first holding section responsive to the first clock signal, maintaining the first node signal at the off-voltage; and a second holding section responsive to the second clock signal, maintaining the first node signal at the off-voltage. The second holding section has a greater transistor width-to-length ratio than the first holding section. Therefore, an abnormal gate-on signal is less likely to occur, reducing driving defects of the display apparatus.

In a control circuit which turns on / off the switching device elements included in a synchronous rectifier step-down switching regulator, a hysteresis comparator compares the detection voltage that corresponds to the output voltage of the step-down switching regulator with a first threshold voltage and a second threshold voltage. A light-load detection circuit detects whether or not a load is in the light-load state. A driver circuit turns on / off the switching device elements according to the pulse signal output from the hysteresis comparator. Upon the light-load detection circuit detecting the light-load state, the hysteresis comparator shifts the second threshold voltage toward the higher-voltage side by a predetermined voltage difference.

According to input parameters, a controller carries out: generation of a voltage command value for each of d- and q-axes; conversion of the voltage command value for each of the d- and q-axes into a voltage command value for each of the multiphase windings; and control of a multiphase inverter based on the voltage command value for each of the multiphase windings. The controller adds, to the voltage command value for the q-axis, a first compensation voltage value for compensating torque ripples to thereby output a compensated voltage command value for the q-axis. The first compensation voltage value contains m-th harmonic components in the AC motor and varies depending on the rotational angle of the rotor, the m corresponding to the number of phase of the multiphase windings. The controller uses, as the voltage command value for the q-axis, the compensated voltage command value for the q-axis.

The present invention provides a ripple compensation method and apparatus that provides a means to compensate for drive current ripple-induced brightness fluctuations in an LEE based illumination system. The ripple compensation apparatus comprises a ripple evaluation module which is configured to evaluate a ripple compensation factor based on an evaluated fluctuation of the drive current. The evaluation of the fluctuation of the drive current can be determined based on information collected during operation of the LEE based illumination system and / or based on predetermined operational characteristics of the LEE based illumination. A control system comprises the ripple evaluation module and is operatively coupled to the one or more light-emitting elements, wherein the control system is configured to determine and provide control signals for operation of the one or more light-emitting elements based on the ripple compensation factor.