11769 results about "Dc converter" patented technology

A DC converter and a mode-switching method used in an electronic apparatus are included. The electronic apparatus includes a subsystem circuit. The DC power converter comprises a first voltage converting circuit electrically connected to the subsystem circuit, receiving a system voltage and a first reference voltage, and converting the system voltage to a first output voltage based on the first reference voltage; and a second voltage converting circuit electrically connected to the subsystem circuit and receiving the system voltage and a second reference voltage, and converting the system voltage to a second output voltage to the same output end of the first voltage converting circuit based on the second reference voltage; wherein the second voltage converting circuit outputs the second output voltage to the subsystem circuit when the first output voltage at the output end is smaller than a threshold.

An energy harvesting circuit includes one or more broadband or narrow band antennas to detect WIFI (wireless fidelity) or other RF (radio frequency) signals. The signals are rectified and voltage multiplied, and the resultant DC voltage is provided to a power management circuit. The output of the power management circuit charges a lithium battery or other storage device within the energy harvesting circuit. The energy stored in the battery or storage device is provided through a DC / DC converter circuit to a USB output connector to power or recharge the batteries of an external electronic device connected to the USB output connector of the energy harvesting circuit.

A grid-connected power system includes a primary power source, a back-up power source, a DC / AC inverter and a DC / DC converter. Direct current from the primary power source is supplied to the DC / AC inverter to obtain an alternating current output supplied to a utility grid when power from the utility grid is available to power a load. The output of the inverter is supplied to a selected portion of the load when power from the utility grid is unavailable to the load. Direct current from the back-up power source is supplied to the inverter through a DC / DC converter when power from the utility grid is unavailable to the load. The DC / DC converter converts the voltage of direct current from the back-up power source to direct current having a voltage compatible with the voltage of the primary power source and the inverter. The back-up power source may be charged by the primary power source or by the utility grid. Methods of providing back-up power include converting the voltage of direct current from a back-up power source to direct current of converted voltage and supplying the direct current of converted voltage to a DC / AC inverter.

A system for providing power from solar cells where each cell or cell array is allowed to produce its maximum available power and converted by its own DC / DC converter. In one form the system includes: one or more solar generators, each of which has at least one solar cell; a maximum power tracker operatively associated with each solar generator, where the maximum power tracker includes a buck type DC / DC converter without an output inductor, and the maximum power trackers of the solar generators are operatively connected in series with each other; and an inductor operatively connected to the series connected maximum power trackers.

A maximum power point tracking method, applied to a tracking device, employs a DC / DC converter connecting with a solar cell array, and including a controller actuating the DC / DC converter to perform an active resistance characteristic; a maximum power point tracking circuit adjusting the active resistance of the DC / DC converter; monitoring a change of an output power of the solar cell array in determining a direction for adjusting the active resistance of the DC / DC converter; and the maximum power point tracking circuit repeatedly adjusting the active resistance of the DC / DC converter. If the change of the output power of the solar cell array is positive, the active resistance of the DC / DC converter is adjusted in the same direction; but, conversely, if the change of the output power of the solar cell array is negative, the active resistance of the DC / DC converter is adjusted in an opposite direction.

The invention provides an optimal electric power converter for a DC / DC converter which variably steps up a voltage successively with an optional magnification of one to two times or more and / or step down a voltage successively with a step-down ratio of one time or less. The converter includes a first input-output part, an inductor connected with a positive or a negative electrode side of the first input-output part, plural switches, plural capacitors, a second input-output part connected with plural capacitors, and a control circuit, wherein the control circuit controls the plural switches with operation mode and makes the inductor and plural capacitors selectively functional, wherein the electric power converter is of a switched capacitance type that performs any operation out of step-up, step-down, regeneration, and continuity, and wherein the control circuit controls to have a period for which two switches out of the plural switches are simultaneously turned ON.

A DC / DC converter includes a pre-converter stage, which may include a charge pump, and a post-regulator stage, which may include a Buck converter. The duty factor of the post-regulator stage is controlled by a feedback path that extends from the output terminal of the DC / DC converter to an input terminal in the post-regulator stage. The pre-converter steps the input DC voltage up or down by a positive or negative integral or fractional value, and the post-regulator steps the voltage down by a variable amount depending on the duty factor at which the post-regulator is driven. The converter overcomes the problems of noise glitches, poor regulation, and instability, even near unity input-to-output voltage conversion ratios.