A line interface filter apparatus to couple a drive or group of drives to a shared multiphase AC bus, including individual phase circuits having an inductor coupled between a respective bus and drive phase lines, a tapped resistor coupled to the respective drive phase line, and a capacitor coupled between the resistor and a common connection of the capacitors of the individual phase circuits, where the capacitance of the capacitors is 5 to 15 times a per-phase equivalent capacitance of the drive or group of drives, and the resistance of the resistors is two times a damping ratio times a square root of a ratio of the filter inductance to the filter capacitance, where the damping ratio ζ is greater than or equal to 1.0 and less than or equal to 2.0.

A line interface filter apparatus to couple a drive or group of drives to a shared multiphase AC bus, including individual phase circuits having an inductor coupled between a respective bus and drive phase lines, a tapped resistor coupled to the respective drive phase line, and a capacitor coupled between the resistor and a common connection of the capacitors of the individual phase circuits, where the capacitance of the capacitors is 5 to 15 times a per-phase equivalent capacitance of the drive or group of drives, and the resistance of the resistors is two times a damping ratio times a square root of a ratio of the filter inductance to the filter capacitance, where the damping ratio ζ is greater than or equal to 1.0 and less than or equal to 2.0.

A monitoring circuit and a method for function monitoring is disclosed where the device includes the input being connected with a first subassembly that detects a frequency range of the status signal, with the first subassembly being connected with a second subassembly to implement a logical signal combination. The second subassembly is connected with a third subassembly generating a delayed output signal. The method compares a frequency fsw of the status signal with a lower first cutoff frequency f1 and an upper second cutoff frequency f2. When the frequency fsw of the status signal is located within the predetermined frequency range, the functional reliability signal is provided with a first voltage level, and when the frequency fsw of the status signal is located outside of the predetermined frequency range, the functional reliability signal is provided with a second voltage level that is different from the first voltage level.

A monitoring circuit and a method for function monitoring is disclosed where the device includes the input being connected with a first subassembly that detects a frequency range of the status signal, with the first subassembly being connected with a second subassembly to implement a logical signal combination. The second subassembly is connected with a third subassembly generating a delayed output signal. The method compares a frequency fsw of the status signal with a lower first cutoff frequency f1 and an upper second cutoff frequency f2. When the frequency fsw of the status signal is located within the predetermined frequency range, the functional reliability signal is provided with a first voltage level, and when the frequency fsw of the status signal is located outside of the predetermined frequency range, the functional reliability signal is provided with a second voltage level that is different from the first voltage level.

A low-pass filter circuit is provided. The low-pass filter circuit includes a low-pass filter and a discharging circuit. The low-pass filter receives an input voltage signal through an input terminal of the low-pass filter circuit during a first period, performs a low-pass filter operation on the input voltage signal to generate a filtered voltage signal, and provides the filtered voltage signal to an output terminal of the low-pass filter circuit. The discharging circuit suppresses a leakage current flowing between the output terminal and a reference low voltage in response to the input voltage signal during the first period.

Trans-filter/Detectors are extremely sensitive circuits that recover exponentially modulated signals buried in noise. They can be used wherever Matched Filter/Coherent Detectors are used and operate at negative input signal-to-noise ratios to recover RADAR, SONAR, communications, or data signals, as well as reduce phase noise of precision oscillators. Input signal and noise is split into two paths where complementary derivatives are extracted. Outputs of the two paths are equal in amplitude and 180 degrees relative to each other at the band center frequency. The outputs are summed, causing stationary in-band noise to be reduced by cancellation while exponentially modulated signals are undiminished. Trans-filters are Linear Time Invariant circuits, have no noise x noise threshold and can be cascaded, increasing output signal-to-noise ratio prior to detection. Trans-filters are most sensitive to all types of digital modulation, producing easily detected polarized pulses synchronous with data transitions. Trans-filters do not require coherent conversion oscillators and complex synchronizing circuits.

Trans-filter/Detectors are extremely sensitive circuits that recover exponentially modulated signals buried in noise. They can be used wherever Matched Filter/Coherent Detectors are used and operate at negative input signal-to-noise ratios to recover RADAR, SONAR, communications, or data signals, as well as reduce phase noise of precision oscillators. Input signal and noise is split into two paths where complementary derivatives are extracted. Outputs of the two paths are equal in amplitude and 180 degrees relative to each other at the band center frequency. The outputs are summed, causing stationary in-band noise to be reduced by cancellation while exponentially modulated signals are undiminished. Trans-filters are Linear Time Invariant circuits, have no noise x noise threshold and can be cascaded, increasing output signal-to-noise ratio prior to detection. Trans-filters are most sensitive to all types of digital modulation, producing easily detected polarized pulses synchronous with data transitions. Trans-filters do not require coherent conversion oscillators and complex synchronizing circuits.

An inductor damper circuit includes a toroidal inductor having an inductor coil and an inductor housing, and a resistive element configured around a periphery of the inductor coil and having one end connected to the toroidal inductor, where the resistive element is printed on a flexible substrate and configured between the inductor coil and the inductor housing, and the resistive element is integrated with the toroidal inductor.

This control device for controlling a loudspeaker (14) in a loudspeaker enclosure, comprises: an input for an audio signal to be reproduced; a supply output for supplying an excitation signal for the loudspeaker; the calculation means (26, 36, 38, 70, 71, 80, 90) for calculating, at each time instant (t), at least one predicted current (i.sub.ref(t)) for the excitation signal for the loudspeaker (14) as a function of the audio signal.

It comprises an attenuator (71) that is capable of limiting the predicted current to a limited current value that is lower than a ceiling value by application, to the predicted current, of an attenuation gain which is a function of the predicted current.

This control device for controlling a loudspeaker (14) in a loudspeaker enclosure, comprises: an input for an audio signal to be reproduced; a supply output for supplying an excitation signal for the loudspeaker; the calculation means (26, 36, 38, 70, 71, 80, 90) for calculating, at each time instant (t), at least one predicted current (i.sub.ref(t)) for the excitation signal for the loudspeaker (14) as a function of the audio signal.

It comprises an attenuator (71) that is capable of limiting the predicted current to a limited current value that is lower than a ceiling value by application, to the predicted current, of an attenuation gain which is a function of the predicted current.