11678 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.

The invention relates generally to systems, devices and methods for the efficient use of utilities, more particularly to the distribution and provision of electricity supply at appropriate voltages, monitoring and usage by end devices, and to facilitating consumers in changing their energy usage behaviour, and to adopt and easily install appropriate sustainable, energy efficient or renewable technologies. Said end devices typically including traditional electric, electronic and lighting appliances requiring AC or DC power provision or low voltage DC power via AC / DC converters.

Method and apparatus for providing a disposable power supply source integrated into the housing of the transmitter unit mount that is placed on the skin of the patient, and configured to receive the transmitter unit is disclosed. The transmitter unit mount is configured to be disposable with the analyte sensor so that power supply providing power to the transmitter unit is also replaced. The transmitter unit may include a rechargeable battery that is recharged by the power supply unit of the transmitter unit mount when the transmitter is mounted to the transmitter unit mount. Other energy store configurations including single large capacitor (supercap) or a capacitor and DC / DC converter configurations are disclosed.

A charging control unit decides the number of battery cells on the basis of an output voltage of a battery pack, and an output voltage of a charging circuit is determined in accordance with the decided number of battery cells. Even though supply of an external power supply is detected, when a battery connection is not detected, the power supply circuit of the charging control unit is set in a stop state. In addition, when disconnection of the battery is detected, a canceling voltage for canceling a cutoff state caused by overdischarging of the battery is output. In a power supply device for a portable terminal, a capacitor electrically charged by an output voltage of main DC / DC converter is connected as an auxiliary power supply of a backup DC / DC converter to make exchange of the auxiliary battery unnecessary.

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.

This invention relates to a Mobile phone battery charger with USB interface which is composed of a compatible plug, an DC converter and a Mobile phone battery charging plug. The compatible plug can be inserted into the USB interface socket of computer or any environmental equipment so as to get electric power from computer, furthermore, the DC converter can convert computer USB interface into necessary charging voltage and transmit to different type Mobile phone by means of the Mobile phone battery charging plug for charging Mobile phone battery. In addition, the Mobile phone battery charger with USB interface also can be connected to various Mobile phone battery charging seat for charging.

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 power supply with AC and DC back-up power has a rectifier, a rechargeable battery, a charger, a detecting circuit, a first DC / DC converter and a DC / AC converter. The rectifier is coupled to the power of the wall-socket for generating a first power. Moreover, the rechargeable battery is charged by the first power through the charger, and the detecting circuit detects a power-supplying condition of the wall-socket. The first DC / DC converter is used to convert a power of either the battery or the first power to a second power, and the DC / AC converter converts a power of the battery into AC power.

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 system (100) for connecting a fuel cell stack to an A.C. grid to provide power thereto is disclosed in which a voltage regulated D.C. bus (110) is provided to be coupled to the fuel cell stack, a bidirectional inverter (120) is coupled to the D.C. bus (110), and is to be coupled between the D.C. bus (110) and the A.C. grid. At least one D.C. auxiliary load (130) of the fuel cell stack is provided coupled to the D.C. bus (110). A D.C. to D.C. converter (140) is provided between the fuel cell stack and the D.C. bus (110).

A main power source (2) is, for example, an ordinary Pb battery and generates a voltage of 12-13 V. At the time of starting an engine, the main power source (2) supplies power to a starter (8a). The main power source (2) is given a higher priority than an auxiliary power source (3) to supply power to ordinary loads (8b). The auxiliary power source (3) is a high performance battery (e.g., Li ion battery), which has superior charge acceptance capability and better state detectability over the main power source (2). Furthermore, the auxiliary power source (3) has an internal resistance per unit capacity, which is smaller than that of the main power source (2), and generates a voltage of 9-12 V. A generator (1) is directly connected to the auxiliary power source (3). The auxiliary power source (3) stores regenerative power, which is generated by the generator (1) at the time of deceleration of a vehicle, and is used as a redundant power source for the main power source (2). The main power source (2) and the auxiliary power source (3) are connected to each other through a supply circuit (5), which has a DC / DC converter (4), and a second supply circuit 7, which has a switch (6).

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.

A solar cell assembly including a plurality of solar cells is formed on a common substrate, and a DC / DC converter which converts the output from the solar cell is connected to each solar cell to constitute a solar power generation apparatus. The output from the solar power generation apparatus is converted into an AC power by an inverter and supplied to a load or commercial AC power system. Since the arrangement is simplified, the manufacturing cost can be reduced, and the influence of partial shade or a variation in characteristic decreases.

A solar cell array control device has a plurality of solar cell modules, a bidirectional DC converter, at least a voltage sensor and a control unit. The bidirectional DC converter corresponds to and is electrically connected to the solar cell modules to connect these solar cell modules in series to form a solar cell array. The voltage sensor is electrically connected to the solar cell modules, and can generate an abnormal voltage when detecting that one of the solar cell modules is abnormal. The control unit is electrically connected to the voltage sensor and the bidirectional DC converter, and outputs a pulse width modulation signal by detecting the abnormal voltage to control the bidirectional DC converter for compensating the conversion current and thus enhancing the output power of this solar cell module.