Abstract: A system includes a power sourcing equipment (PSE) unit. The PSE unit includes a plurality of network ports. The PSE unit also includes a PSE board coupled to the plurality of network ports and configured to provide power to a plurality of powered devices (PDs) external to the PSE unit via respective network ports. The PSE unit also includes a sensing circuit configured to determine a power consumption parameter for the PSE board. The PSE unit also includes a controller configured to change a power state for at least one of the plurality of network ports based at least in part on the power consumption parameter.

Abstract: A system includes a power sourcing equipment (PSE) unit. The PSE unit includes a plurality of network ports. The PSE unit also includes a PSE board coupled to the plurality of network ports and configured to provide power to a plurality of powered devices (PDs) external to the PSE unit via respective network ports. The PSE unit also includes a sensing circuit configured to determine a power consumption parameter for the PSE board. The PSE unit also includes a controller configured to change a power state for at least one of the plurality of network ports based at least in part on the power consumption parameter.

Abstract: Methods and apparatus to improve power factor are disclosed. An example method includes detecting power provided to a power factor corrector; detecting power provided by the power factor corrector; and disabling the power factor corrector from correcting a power factor of a load for at least one period when the power provided by the power factor corrector is below a light-load threshold.

Abstract: Systems and methods of LED dimmer compatibility offer LED systems that fit in applications regardless of whether a dimmer is present or the type of dimmer switch that is used. These systems and methods provide high power factor without wasting energy. There are at least three types of wave forms that the LED device may see. The compatibility circuit may be integrated into the LED device such that the device may be screwed into any existing light socket. The device may be usable in a socket whether or not a dimmer is on the line. If a dimmer is present, it may be a trailing edge dimmer or leading edge dimmer. If no dimmer is present on the line, the LED illumination device receives a direct AC line input. The switching of the output transistor of the PFC stage is intelligently applied based on the type of dimmer present.

Abstract: Methods and apparatus to improve power factor are disclosed. An example method includes detecting power provided to a power factor corrector; detecting power provided by the power factor corrector; and disabling the power factor corrector from correcting a power factor of a load for at least one period when the power provided by the power factor corrector is below a light-load threshold.

Abstract: A quantized voltage feed-forward (QVFF) circuit and integrated circuits using this technique. The QVFF circuit includes a plurality of comparators in combination with a logic control circuit. The comparators are structured and arranged to establish various voltage threshold levels, each providing a digital state signal representative of the sensed input voltage level. The logic control circuit is structured and arranged to use the digital input signals from the comparators to output a voltage feed-forward factor (KVFF) signal that is representative of the V2rms voltage. Output from the logic control circuit is provided to an analog signal multiplier and used to shape an input current reference (IMO) waveform. This allows detection of changes in the rms level of the input voltage on the half-cycle of the AC line voltage, resulting in a rapid response to line voltage changes. Because the KVFF factor signal contains no AC ripple component, it does not contribute to THD of the input current reference, IMO.

Abstract: Systems and devices for reduction of total harmonic distortion in power supply circuits are presented. Example embodiments of the disclosed systems of total harmonic distortion reduction reduce a low frequency output voltage ripple seen by the voltage control loop by adding a compensating ripple voltage to the output feedback signal. The compensating signal may be scaled by the user to optimize the degree of ripple reduction, and may be automatically adjusted by monitoring circuitry to scale with a power factor control circuit output power level.

Abstract: A quantized voltage feed-forward (QVFF) circuit and integrated circuits using the same. The QVFF circuit includes a plurality of comparators in combination with a logic control circuit. The comparators are structured and arranged to establish various voltage threshold levels, each providing a digital state signal representative of the sensed input voltage level. The logic control circuit is structured and arranged to use the digital input signals from the comparators to output a voltage feed-forward factor (KVFF) signal that is representative of the V2rms voltage. Output from the logic control circuit is provided to an analog signal multiplier and used to shape an input current reference (IMO) waveform. This allows detection of changes in the rms level of the input voltage on the half-cycle of the AC line voltage, resulting in a rapid response to line voltage changes. Because the KVFF factor signal contains no AC ripple component, it does not contribute to THD of the input current reference, IMO.