Electronic filter

About: Electronic filter is a research topic. Over the lifetime, 13207 publications have been published within this topic receiving 93063 citations. The topic is also known as: filter.

Volumetric optimization of passive filter for power electronics input stage in the more electrical aircraft

Abstract: The increasing number of power electronic converters connected to aircraft electrical supply networks increases the harmonic levels. Conventional filter design is not well adapted to many power converters, since their behaviour is strongly coupled with filter values. This paper proposes a methodology to optimize a passive input filter and to fulfil harmonic and power factor standards. The method is applied to a diode rectifier, with capacitive load, which represents a very common power input stage for actuators.

Phase-locked loop

Abstract: A phase-locked loop (PLL) having very fast acquisition, and low output phase jitter and stability at steady-state is provided In general, the phase-locked loop is used for synchronizing an output signal of said phase-locked loop with an input reference signal In accordance with a general inventive concept, the filter circuit (4D) of the phase-locked loop includes a differentiator (5D) responsive to the phase difference representing signal from a phase detector (2D) in the PLL for providing a differentiated signal, and a filter (6D) responsive to both the phase difference representing signal and the differentiated signal to provide a filter output signal Preferably, the filter (6D) is a low-pass filter The output signal source (9) of the PLL is controlled by a control signal which is generally based on the filter output signal

Rotation control apparatus for a motor

Abstract: A rotation control apparatus for a motor comprises a motor for rotating or moving a recording medium, a circuit for generating first and second reference signals, a circuit for passing a signal which is obtained by comparing phases of the first reference signal and a synchronizing signal through a filter circuit thereof so as to produce a first error signal therefrom, a circuit for producing a second error signal which is obtained by comparing phases of the second reference signal and the rotation detection signal, and a control circuit for controlling first and second switching circuits. The control circuit supplies a specific signal having a level dependent on the level of the second error signal to a capacitor of the filter circuit through the second switching circuit and selectively passes the second error signal through the first switching circuit when the motor rotates at a rotational speed which is not near a steady state rotational speed. The control circuit blocks the supply of the specific signal to the capacitor by the first switching circuit and selectively passes the first error signal through the first switching circuit when the motor rotates at a rotational speed which is approximately equal to the steady state rotational speed.

Development of UWB HTS Bandpass Filters With Microstrip Stubs-Loaded Three-Mode Resonator

Abstract: We developed ultra-wideband high-temperature superconducting bandpass filters for Japan's low-band spectrum. First, we designed a low-band filter with a microstrip three-mode resonator loaded with two open stubs. The three-mode resonator is characterized by the ease of controlling the frequency response compared with other resonators. In addition, we loaded a low-pass filter consisting of a microstrip coupled-line hairpin unit to suppress all unwanted high-frequency harmonics. The simulated filtering characteristics of the low-band filter showed a wide passband within 3.44-4.67 GHz with a minimum insertion loss of 0.06 dB. After that, we fabricated a low-band filter with YBCO thin films deposited on sapphire substrates. The frequency response of the fabricated filter was clearly observed at 70 K, and the measured response without any tuning matched well with the simulated one. The measured filtering characteristics showed a wide passband within 3.46-4.80 GHz with a minimum insertion loss of 0.01 dB. The box resonances of the copper housing were suppressed by introducing radar absorbent material under the top metal.

Hybrid Conditioner for a Power System

Abstract: A hybrid conditioner for filtering harmonics in a power system that includes a non-linear load. The hybrid conditioner includes an active filter structured and controlled to filter one or more high-order harmonic currents of the fundamental frequency, and a passive filter structured to filter one or more low-order harmonic currents of the fundamental frequency. The active filter and the passive filter are electrically connected in parallel with one another. The hybrid conditioner may also be for providing reactive power compensation for the power system, wherein the active filter is further controlled to provide a compensatory reactive power for compensating for the reactive power that is consumed by the load. The hybrid conditioner may also provide oscillation dampening for the power system, wherein the active filter is further controlled to damp oscillating currents that exist between the passive filter and the AC source.