Abstract: The present invention provides a capacitor charging circuit that efficiently charges capacitive loads. In particular, circuits and techniques are preferably provided for using current from both the primary and secondary windings of a transformer to control ON-time and OFF-time of a switch. This arrangement preferably yields an adaptable ON-time and adaptable OFF-time switch that is capable of rapidly charging capacitor loads ranging from as low as zero volts to several hundred volts. The output voltage is preferably measured indirectly to prevent unnecessary power consumption. In addition, control circuitry can be provided to conserve power by ceasing the delivery of power to the capacitor load once the desired output voltage is reached. Control circuitry preferably operates an interrogation timer that periodically activates the power delivery cycle to maintain the capacitor output load in a constant state of readiness.

Abstract: The present invention provides a capacitor charging circuit that efficiently charges capacitive loads. In particular, circuits and techniques are preferably provided for using current from both the primary and secondary windings of a transformer to control ON-time and OFF-time of a switch. This arrangement preferably yields an adaptable ON-time and adaptable OFF-time switch that is capable of rapidly charging capacitor loads ranging from as low as zero volts to several hundred volts. The output voltage is preferably measured indirectly to prevent unnecessary power consumption. In addition, control circuitry can be provided to conserve power by ceasing the delivery of power to the capacitor load once the desired output voltage is reached. Control circuitry preferably operates an interrogation timer that periodically activates the power delivery cycle to maintain the capacitor output load in a constant state of readiness.

Abstract: The present invention provides a capacitor charging circuit that efficiently charges capacitive loads. In particular, circuits and techniques are preferably provided for using current from both the primary and secondary windings of a transformer to control ON-time and OFF-time of a switch. This arrangement preferably yields an adaptable ON-time and adaptable OFF-time switch that is capable of rapidly charging capacitor loads ranging from as low as zero volts to several hundred volts. The output voltage is preferably measured indirectly to prevent unnecessary power consumption. In addition, control circuitry can be provided to conserve power by ceasing the delivery of power to the capacitor load once the desired output voltage is reached. Control circuitry preferably operates an interrogation timer that periodically activates the power delivery cycle to maintain the capacitor output load in a constant state of readiness.

Abstract: The invention provides buck switching regulator circuits that include voltage slew rate limiting circuitry and current slew rate limiting circuitry. The specification describes current-mode and voltage-mode control implementations that provide efficient low-noise switching regulator circuits.

Abstract: The present invention relates to circuits and methods for improving the efficiency of step down switching regulators converting a high input voltage to a low output voltage. Furthermore, the present invention relates to circuits and methods to achieve such efficiency improvements while maintaining controllability during light output load conditions. In a preferred embodiment, the current mode switching regulator circuit includes a logic section, an output switch section controlled by the logic section, an oscillator for providing periodic timing signals to the logic section to turn the output switch ON, a feedback amplifier for developing an integrated error signal based on the output voltage, and a current comparator including an output, the current comparator for comparing the integrated error signal to the instantaneous value of the current in the output switch, the output of the comparator producing a signal which causes the logic section to turn the output switch OFF.

Abstract: Control circuits for a flyback switching voltage regulator that uses magnetic flux sensing are provided. These circuits include a flyback error amplifier circuit, a logic circuit, and a load compensation circuit. The flyback error amplifier circuit allows a flyback voltage pulse from a primary transformer winding to be employed for output voltage regulation. The logic circuit provides appropriate timing and control signals for the flyback error amplifier circuit. The load compensation circuit compensates for parasitic impedance contributions to the flyback voltage pulse without altering the stability of the flyback regulator.

Abstract: A threshold detector for detecting the recurrence of a respiration event by comparing a filtered respiration signal to an adjustable threshold level. The adjustable threshold level is maintained at a value sufficient to substantially prevent the detector from indicating that a respiration event has occurred due to residual cardiovascular artifact being present in the filtered respiration signal.

Abstract: Systems and methods are disclosd for detecting the recurrence of physiological functions. The disclosed systems and methods are especially adapted for detecting the recurrence of a patient's respiration from a signal representative of changes in the patient's thoracic volume, despite the presence of cardiovascular artifact in the signal. A cardiovascular artifact filter suppresses the artifacts in response to a signal, generated by a cardiotachometer, which varies as and is proportional to the fundamental frequency of each artifact.

Abstract: For suppressing cardiovascular artifact present in a respiration signal, a cardiovascular artifact filter suppresses artifacts in response to an output signal generated by a cardiotachometer. The output signal is proportional to the fundamental frequency of the cardiovascular artifact. Recurrence of respiration is determined by coupling the filter to a threshold detector. A minimum threshold level proportional to the maximum amplitude of the artifact is supplied to the detector for minimizing the false indication of respiration recurrence due to presence of an artifact in the respiration signal.