481 results about "Power filter" patented technology

An exemplary parallel hybrid power filter apparatus for the electrified railway is described. The apparatus may include a group of LC reactive filter being purely tuned, an additional inductance, an active power filter and a coupling transformer. The active power filter may be controlled, e.g., as a current source in a composite control manner and can be connected in parallel to the additional inductance via the coupling transformer. The power filter can be connected to the reactive filter in series to form the parallel hybrid filtering system, and may be connected to the power grid via the circuit breaker or a thyristor. This exemplary system can be installed either in the traction substations or in the locomotives directly, or performed by ameliorating the original reactive filter. The active power filter does not add significant amount of cost, and may be simple and reliable in a control manner for the capacity of the APF is so small as to be less than one percent of that of the harmonics source. The power filter can also inhibit the impact of the “background harmonics” of the electrified railway on the reactive filter, and prevent the reactive filter and the grid impedance from resonance.

The invention provides a refrigeration-type coaxial packaging light-emitting tube core, which comprises a transistor outline (TO) tube shell, a refrigerator, a heat sink, a laser carrier and a sealing tube cap, wherein the TO tube shell comprises a tube shell base. At least seven pins are arranged around the tube shell base; the pins comprise a radio frequency (RF) signal pin, and the laser carrier with a microstrip line is arranged on the RF signal pin; the radiating surface of the refrigerator and the surface of the tube shell base are fixed in the manner of sticking; the refrigeration surface of the refrigerator and the surface of the heat sink are fixed in the manner of sticking; the heat sink and the surface of the laser carrier with a matched resistor and the microstrip line are fixed in the manner of sticking; an electric absorption modulation laser chip, a backlight detector, a thermistor and a power filter capacitor are fixedly arranged on the surface of the laser carrier in the manner of sticking; one end of the microstrip line of the laser carrier is connected with the anode of an electric absorption modulator; and the other end of the microstrip line of the laser carrier is connected with a microstrip line on the RF signal pin through a conductor wire. When installation is performed, the emitted light outlet optical axis of the laser chip and the optical axis (OA) of the central axis of the TO tube shell are coaxial. Optical steering elements are not needed, the process is simple, and the signal distortion can be reduced.

Disclosed are apparatus and methodology for providing controlled equivalent series resistance (ESR) decoupling capacitor designs having broad applicability to signal and power filtering technologies. Such capacitor designs provide characteristics for use in decoupling applications involving both signal level and power level environments. Controlled equivalent series resistance (ESR) is provided by providing extended length tab connections to active electrode layers within the device.

An I/O system and device for use with superconducting device provides multi-stage filtering using superconducting electrical pathways, while providing good thermal conductivity to maintain low temperature of the various components and allowing the easy mounting and dismounting of a device sample from a refrigerated environment. Filtering may include a lumped element filter assembly including multiple plates each carrying a number of lumped element filters. Filtering may include a metal powder filter assembly including multiple metal power filters formed in passages of a substantially non-magnetic portions. A device sample holder assembly secures a device sample, for example a superconducting quantum processor, and provides signals, ground and good thermal conduction.

Disclosed are apparatus and methodology for providing land grid feedthrough capacitor designs having broad applicability to signal and power filtering technologies. Such capacitor designs provide characteristics for use in decoupling applications involving both signal level and power level environments. Low equivalent series inductance (ESL) is provided by current cancellation techniques involving opposite current flow in power or signal and ground current paths through the device.

The invention relates to an electronic ballast of an alternate current high-power LED illumination energy-saving lamp, which belongs to the field of electric illumination energy conservation. The electronic ballast comprises a casing and a control circuit in the casing, and is characterized in that the control circuit comprises a rectifying circuit, a PFC power factor correction circuit, a light energy conversion controller circuit, an LED luminous device, a constant current drive control circuit, a loop current detection circuit, and the like; the main circuit of the rectifying circuit is connected with a follow current compensation circuit via the PFC power factor correction circuit and a power filter circuit; a bypass circuit of the rectifying circuit is connected with a controller power supply circuit which is respectively connected with a linear dimming circuit and the light energy conversion controller circuit; the loop of the LED luminous device is connected with the constant current drive control circuit and then is connected with the loop current detection circuit; and the loop current detection circuit is connected with the light energy conversion controller circuit. The electronic ballast has the advantages of small volume, simple structure, high electricity saving efficiency, long service life, and the like.

The invention discloses a digital switching power source with high light-load efficiency. The digital switching power source comprises an alternating current input power source, an EMI filter, a rectifier bridge, a pre PFC correcting circuit, a transformer, a post DC/DC conversion circuit, a sampling circuit, a first drive circuit, a second drive circuit, a first DSC and a second DSC. The light-load efficiency is improved by reducing the switching loss of a MOS pipe in the pre PFC correcting circuit, the switching loss of a MOS pipe in the post DC/DC conversion circuit and the magnetic core loss of an inductor on the condition of light loads. Compared with other methods for improving light-load efficiency, no additional circuit is needed, and the purpose of improving the high-load efficiency of the power source can be achieved only by using an original control circuit and simply changing relates control strategies; therefore, the digital switching power source is high in light-load efficiency, simple in structure, low in cost and good in reliability.

A device, system and method for a backup power supply are disclosed herein. The backup power supply may use at least one ultra capacitor to store a voltage. The backup power supply may also have a multiphase boost converter to provide a relatively constant voltage from the stored voltage and a constant changing power filter to regulate a current that is used to charge the ultra capacitor. A charging and discharging controller may be used to monitor the status of a power supply and control the charging and discharging of the ultra capacitors.

The invention relates to a static reactive power compensator adjusting method used in power transmission system. It comprises three combined regulation control tactics: it controls the reactor (TCR) antennal organs which is controlled by the bus wire thyristor to do perceptual reactive-load power constant adjustment; it controls the power filter device group (FC) and the fixed condenser band to do condenser reactive-load power interval adjustment; it controls the load transformer tapping switch (LTC) to do bus wire adjustment.

The present invention constitutes a control circuit which permits the dimming of the illumination emitted from a fluorescent lamp. A controllable source of alternating current power is converted to direct current utilizing a conventional diode bridge and power filter. The direct current signal is converted to a high frequency alternating current signal using a self-oscillating inverter circuit. The output of the inverter circuit is coupled to a resonance circuit. The lamp will be turned on when the output of the resonance circuit is increased until it exceeds the minimum voltage specified for the selected fluorescent lamp. A voltage doubler circuit powers the fluorescent lamp and permits the fluorescent lamp to be dimmed or otherwise remain illuminated when the input alternating power is reduced below that specified for normal operation of the fluorescent lamp.

A hybrid-STATCOM for providing compensating reactive power required by a load, the hybrid-STATCOM comprising: a TCLC part for each electric power phase, each TCLC part comprising: a coupling inductor; a power filter capacitor; and a thyristor-controlled reactor connected in series with a power filter inductor; and an active inverter part comprising: a voltage source inverter for each electric power phase; and a DC-link capacitor connected in parallel with the voltage source inverters. The control strategy of the hybrid-STATCOM is separated into two parts: TCLC part control and Active inverter part control. The TCLC part control is based on the instantaneous pq theory and aims to compensate the loading reactive power with the controllable TCLC part impedance. The active inverter part control is based on the instantaneous active and reactive current i_d-i_q method and aims to improve the overall performance of the hybrid-STATCOM under different voltage and current conditions.

The invention relates to a power filter in a power filtering and protection technique, in particular to a transient state and stable state resisting combination interference power filter and a design method thereof. The power filter is characterized by at least comprising protection circuits and filter circuits, wherein the protection circuits are connected with the filter circuits in series; the filter circuits are packaged in a filter shell, which has a nickel-plated surface and is made of cold-rolled steel plates, at a constant temperature through epoxy resin; the filter circuits are type A, type U, type D and type F filter circuits; and the protection circuits are provided with TVS tubes on line-line and line-ground of input ends of the filter circuits respectively to form a line-line and line-ground transient protection module. The transient state and stable state resisting combination interference power filter not only has good common mode and difference mode filtering performance, but also can effectively inhibit surge interferences on a power line, and is particularly suitable for various types of direct current electronic devices having high requirements on CS116.

This invention discloses a control method for oscillation suppression based on composite power filter, which introduces APF into PPF to compose composite PF system with compensation performance improved greatly and achieved nation standard. Wherein, arranging inductance La in series with APF to compose current source for harmonic wave and interval harmonic wave and make harmonic compositions in load current flow into composite filter system and interval harmonic compositions flow into power network side, which will bring amplification or resonance, decrease APF capacity. The invention improves greatly harmonic wave compensation effect and reliability for existing PPF device.

The present invention discloses a control method for a soft switch circuit in a switch power source, which generates an alternating primary power filter current by controlling first and second primary power switching devices to be closed and opened, and generates an intermittent alternating resonant current in the same direction as the primary power filter current in a resonant branch by controlling forward and backward auxiliary switching devices to be closed and opened to thereby achieve closing of the first and second primary power switching devices at a zero voltage, and which generates a balance current with the same magnitude as and in the opposite direction to the resonant current in the resonant branch in at least a period of time during the resting of the resonant current by further controlling the forward and backward auxiliary switching devices to be closed and opened to thereby achieve an average current of zero across the resonant branch in a switching cycle. Without any additional balance circuit, this control method can address the imbalance problem of output power of the positive and negative direct current input voltage sources in a soft switch circuit of an existing switch power source.

The invention discloses an electromagnetic shielding machine case which is composed of a machine case housing (1), side panels (9), waveguide windows, an aviation plug (8) and a power filter (12). Two side panels (9) are arranged on choke grooves (13) on two lateral sides of the machine case housing (1) respectively, the aviation plug (8) and the power filter (12) are arranged in the machine case housing (1), and a front side panel (6) and a rear side panel (11) are respectively provided with a waveguide window to achieve a purpose of efficient shielding. The electromagnetic shielding machine case is clear in structure and good in practicality, achieves the purposes of being convenient to move, high in shielding efficiency, safety and reliability, good in environment adaptation and wide in application range, solves the problems of computer damage caused by electronic pulse and electromagnetic information leaking and is suitable for military and confidential situations.

The invention discloses a power divider with a double-band filter function, comprising an upper micro-strip structure, an isolation resistor, a medium dielectric substrate, and an underlying metal floor. The upper micro-strip structure includes four resonators, three feeders and one isolation resistor, and the upper micro-strip structure is arranged into two band-pass filter circuits of longitudinal symmetry. The power filter not only can achieve the characteristic of center frequency-adjustable double-bandpass filter, but also has the same characteristics as a power divider of which the power allocation ratio is 1:1. The resonators are quarter-wave short-circuit line resonators respectively loaded with a branch, and the characteristic of double-band bandpass filter with center frequency independently controllable is realized by adjusting the length of the branches. The resistor connecting two filter networks realizes matching of three ports of the circuit and isolation between two output ports. In addition, four transmission zeroes are introduced through source load coupling, which enables the power divider to have high selectivity and a good stop-band suppression effect, and is more conductive to integration and miniaturization of devices.

The invention discloses a display module and a rugged tablet personal computer thereof. The display module comprises a panel module unit and an LCD (Light Crystal Display) module unit which are independent mutually, wherein the panel module unit is arranged in front of the LCD module unit and is detachably and fixedly connected with the LCD module unit. The rugged tablet personal computer comprises a host module and a display module, wherein the host module and the display module are independent respectively and are detachably and fixedly connected together; the host module comprises a rear cover and a host unit arranged in the rear cover; the host unit comprises a mainboard, a rigid disk, an IO (Input/Output) interface board, a power source and a power filter; the mainboard is respectively and electrically connected with the IO interface board, the power source and the power filter; and the mainboard is spliced with the IO interface board. The display module provided by the invention is strong in compatibility and easy to maintain and replace. The rugged tablet personal computer has the characteristics of complete computer modularization, high assembling efficiency, easiness for maintaining and replacing and balanced customization and industrialization.

The invention discloses a single ultraviolet phototube optical detector for fire detection at high temperature. The single ultraviolet phototube optical detector comprises a power filtering conversion circuit, an ultraviolet sensing circuit, a temperature compensation circuit, a window contamination detection circuit, a CPU (central processing unit) interface circuit, a serial port communication circuit and an indicator light circuit. Information of operation state and the like can be transmitted to an upper computer timely by serial port communication. A single ultraviolet photounit adaptive to ultraviolet light of flame is used, so that infrared radiation interference of a power chamber at high temperature is avoided, fire detection is highly accurate, and anti-false-positive capacity is high. Temperature compensation is performed by CPU sampling and calculation, time detectivity is consistent at wide temperature, and intelligent degree is increased remarkably. The condition that window glass is contaminated by oil in the power chamber can be detected by the window contamination detection circuit and reported to the upper computer.