A configurable impedance circuit is provided, including a filter for filtering a received DC voltage and a controller. The filter includes a first capacitor, a second capacitor, and a selectable switch coupled in series with the second capacitor and coupled to receive a control signal. The selectable switch and the second capacitor are selectively coupled in parallel with the first capacitor. The controller is connected to sense a differential voltage across the second capacitor and configured to generate the control signal to open or close the selectable switch based on the differential voltage across the second capacitor, so as to maintain a voltage range across the second capacitor. According to disclosure of the present invention, the total physical size of the capacitors is reduced and the size of the power supply is reduced accordingly.

Apparatus and techniques described herein can include using an electronic circuit comprising a rectifier circuit, an open-circuit voltage (OCV) sampling circuit coupled to the output of the rectifier circuit, and a regulator circuit coupled to the output of the rectifier circuit. In an example, an isolation switch can be located between the regulator circuit and the rectifier circuit, the isolation switch configured to isolate the regulator circuit from the rectifier circuit for sampling of the open-circuit voltage by the open-circuit voltage sampling circuit. In another example, a buffer circuit can be used, such as placed in-line with a divider circuit between a divider circuit and an open-circuit voltage sampling capacitor. In this manner, the buffer circuit can provide a low output impedance, isolating the voltage sampling capacitor from the divider circuit.

An electrical power conversion system for converting a high voltage from a HV electrical power supply to a low voltage is disclosed. In an embodiment, the electrical power conversion system includes at least one power converter and at least one RC network including a plurality of resistive components and a plurality of capacitive components electrically connected in series. In an embodiment, the at least one RC network is in series connection with the at least one power converter and the at least one RC network and at least one power converter are arranged to be connected across a line potential of the HV electrical power supply.

Disclosed are bias voltage generating circuits and methods for a switching power supply. In one embodiment, a switching power supply can include: (i) a driver circuit configured to receive a bias voltage, and to drive a switch in a power stage of the switching power supply; (ii) where a ratio of an output voltage of the switching power supply to an expected bias voltage of the driver circuit is configured as a proportionality coefficient; (iii) a bias voltage generating circuit configured to generate the bias voltage for the driver circuit based on a first voltage; and (iv) an H-shaped inductor coupled to an input of the bias voltage generating circuit, where the first voltage is configured to be generated based on a number of turns of the H-shaped inductor and the proportionality coefficient.

A linear generator includes a permanent magnet array having at least two magnets arranged end-to-end. A set of conductive coils is arranged around the permanent magnet array. A four-phase full wave rectifier is configured to accept alternating current inputs from the set of conductive coils and to produce one or more direct current outputs. A summing circuit is configured to aggregate the one or more direct current outputs from the rectifier to produce a combined, rectified direct current output.

Apparatus and techniques described herein can include using an electronic circuit comprising a rectifier circuit, an open-circuit voltage (OCV) sampling circuit coupled to the output of the rectifier circuit, and a regulator circuit coupled to the output of the rectifier circuit. In an example, an isolation switch can be located between the regulator circuit and the rectifier circuit, the isolation switch configured to isolate the regulator circuit from the rectifier circuit for sampling of the open-circuit voltage by the open-circuit voltage sampling circuit. In another example, a buffer circuit can be used, such as placed in-line with a divider circuit between a divider circuit and an open-circuit voltage sampling capacitor. In this manner, the buffer circuit can provide a low output impedance, isolating the voltage sampling capacitor from the divider circuit.

The number of constituent components is reduced so as to provide a small-size and inexpensive electric-power conversion system. The electric-power conversion system is provided with an inverter circuit (14) connected with the rear stage of an AC power source, a smoothing capacitor (22) connected with the rear stage of the inverter circuit (14) by way of a rectifying device (20), a charging switch (2) that is connected with the front stage of the inverter circuit (14), that inputs an electric quantity based on an output of the AC power source (1) to the inverter circuit (14) when being turned on, and that cuts off an input of the electric quantity to the inverter circuit (14) when being turned off, and an inrush current prevention circuit (7) having an inrush current prevention switch (3) and an inrush current prevention resistor (4) that is connected in series with the rear stage of the inrush current prevention switch (3); the electric-power conversion system is characterized in that the inrush current prevention circuit (7) is connected in parallel with the charging switch (2).

A buoy includes a flotation device configured to float at surface of a body of water. A vibrational linear electric generator (VLEG) is configured to generate power from vibrational oscillations caused by waves using compressed repulsive magnetic fields focused by end magnetic field deflecting magnets. A power collection circuit, which includes a first battery, is configured to collect and store energy generated by the VLEG. One or more electronic components are powered by the vibrational linear electric generator.

A power converter in a powered device (PD) of Power-over-Ethernet (PoE) system and a control method are provided. The power converter includes a transformer, a PD interface, a primary-side controller and a detecting circuit. The PD interface receives an input voltage to determine a PoE protocol type of the input voltage, so as to generate a first power type signal. The primary-side controller receives the first power type signal to adjust a primary-side control signal, wherein a primary-side switch is controlled by the primary-side control signal. The detecting circuit detects a mapping signal generated in a secondary-side winding according to the primary-side control signal to generate a second power type signal, wherein the second power type signal indicates the PoE protocol type of the input voltage.

An apparatus may include a dimmer output voltage emulator for causing a power converter interface circuit to draw current from a capacitor in the power converter interface during a period of time when a dimmer coupled to the power converter interface circuit is non-conducting to generate an emulated dimmer output voltage. The emulated dimmer output voltage may emulate part of a cycle of a non-zero AC dimmer output voltage of the dimmer after a triac of the dimmer prematurely stops conducting that would occur if the triac continued conducting during the part of the cycle. The dimmer output voltage emulator may include a pull-down circuit to pull down current of the interface circuit and generally decrease the emulated dimmer output voltage during a first period of time and a hold circuit to maintain the emulated dimmer output voltage below a substantially non-zero threshold value during a second period of time.