Methods and apparatus for providing and controlling power to loads including one or more LEDs. In one example, a controlled predetermined power is provided to a load without requiring any feedback information from the load (i.e., without monitoring a load voltage and/or load current). In another example, a “feed-forward” power driver for an LED-based light source combines the functionality of a DC-DC converter and a light source controller, and is configured to control the intensity of light generated by the light source based on modulating the average power delivered to the light source in a given time period, without monitoring and/or regulating the voltage or current provided to the light source. In various examples, significantly streamlined circuits having fewer components, higher overall power efficiencies, and smaller space requirements are realized. Based on various power driver configurations, lighting apparatus incorporating one or more power drivers for one or more LED-based loads may be implemented, and multiple such lighting apparatus may be coupled together to form a lighting network in which operating power is efficiently provided throughout the network.

LED power control methods and apparatus

An inductive power transfer system (1) comprises a primary unit (10) operable to generate an electromagnetic field and at least one secondary device (30), separable from the primary unit, and adapted to couple with the field when the secondary device is in proximity to the primary unit so that power can be received inductively by the secondary device from the primary unit without direct electrical conductive contacts therebetween. The system detects if there is a substantial difference between, on the one hand, a power drawn from the primary unit and, on the other hand, a power required by the secondary device or, if there is more than one secondary device, a combined power required by the secondary devices. Following such detection, the system restricts or stops the inductive power supply from the primary unit. Such a system can detect the presence of unwanted parasitic loads in the vicinity of the primary unit reliably.

Controlling inductive power transfer systems

An adaptive inductive ballast is provided with the capability to communicate with a remote device powered by the ballast. To improve the operation of the ballast, the ballast changes its operating characteristics based upon information received from the remote device. Further, the ballast may provide a path for the remote device to communicate with device other than the adaptive inductive ballast.

Adaptive inductive power supply with communication

Methods, apparatus, and articles of manufacture to power a device using wirelessly transmitted power are disclosed. Initially, a wireless base unit obtains a request for wireless power. The wireless base unit then determines a power requirement associated with a wireless field unit and compares the power requirement to a remaining power capacity of the wireless base unit. The wireless base unit then transmits power wirelessly to the wireless field unit based on the comparison of the power requirement to the remaining power capacity. The wirelessly transmitted power is associated with powering a field device operatively coupled to the wireless field unit.

Wireless power transmission systems and methods

A method and apparatus for providing power to e.g., a chargeable device via a radio frequency link. In one aspect, a method of providing power to a chargeable device via radio frequency link comprises generating a substantially un-modulated signal. The method further comprises radiating a substantially un-modulated radio frequency (RF) signal to the chargeable device via a transmit antenna based on the substantially un-modulated signal. The method further comprises powering or charging the chargeable device with power delivered by the substantially un-modulated RF signal.

Method and apparatus for delivering energy to an electrical or electronic device via a wireless link

The invention describes a system for electrical transmission in the field of garments and a corresponding transmitter for this. Electrical circuits in garments are coupled, preferably inductively in a wireless manner with electrical devices and/or electrical circuits in other garments, wherein electrical energy is transmitted via the coupling. Energy transmission in both directions is preferably possible, wherein a distributed system results with sources and devices that can be coupled with each other. The efficiency of the inductive energy transmission is increased by regulation of the frequency, preferably using resonance. In addition, means for information transmission are proposed.

System for wireless transmission of electrical power, a garment, a system of garments and method for the transmission of signals and/or electrical energy

Gate drivers generate significant losses, especially at high frequencies. While conventional solutions dissipate all the energy, resonant gate drivers partly recover it. A resonant gate driver is studied in detail with the emphasis on PWM operation. Compared to other resonant drivers, the investigated driver combines simplicity, fast switching and loss reduction. Advantages and limits are discussed using a mathematical model and a prototype.

A detailed analysis of a resonant gate driver for PWM applications

A circuit arrangement for generating at least a DC output voltage (at 18, 19) from an at least substantially sine-shaped AC input voltage (at 2, 3) of a first frequency by a first rectifier arrangement (1) to which the AC input voltage can be applied (at 2, 3) and which has a DC output (4, 5) from which a rectified voltage is obtainable, a first inductance (6), a second rectifier arrangement (7) and a first filter capacitance (8) which, in this order, constitute a series arrangement connected parallel to the DC output (4, 5), a switched-mode power supply (9) having two input terminals (10, 11) with which it is arranged parallel to the first filter capacitance (8) and between which it includes a series arrangement of a second inductance (12) and a switching device (13) which is alternately switchable in the conducting state and in the blocked state at a second frequency and from which the DC output voltage(s) is (are) obtainable (at 18, 19), as well as a first control capacitance (23) by which the junction point (22) between the first inductance (6) and the second rectifier arrangement (7) is combined with the junction point (24) between the second inductance (12) and the switching device (13), as well as the series arrangement of a second control capacitance (28) and a second switching device (29) which is arranged parallel to the first control capacitance (23) between the junction points (22) and (24), the first inductance (6) and the first control capacitance (23) being dimensioned in such a way that a resonance frequency determined thereby is larger than the second frequency and the last-mentioned frequency is chosen to be large with respect to the first frequency, while the second control capacitance (28) is chosen to be large with respect to the first control capacitance (23). While using a small number of components, both the voltage rise at the switching device and thus the high-frequency interference originating therefrom can be reduced under all occurring circumstances, and the harmonics of the line current can also be reduced. Moreover, the maximum voltage occurring at the switching elements may be limited to a predetermined value without any additional losses.

Circuit arrangement for generating a DC-separated output voltage

A conversion circuit for converting solar power into an alternating 3-phase maims (M) comprises a converter (conv) for converting the power from a solar cell (sc) into an unipolar converter output voltage provided between a first and a second converter output terminal of the converter, the converter having a constant power output regulation. The conversion circuit further comprises an inverter (Inv) for cyclically switching one of 3 3-phase output terminals to the first converter output terminal, one to the second converter output terminal and one intermittently to the first and second converter output terminal. With this conversion circuit and method, high capacity energy storage components (such as a capacitor having a large capacitance) can be avoided in the conversion circuit.

3-phase solar converter circuit and method

The invention relates to a circuit for converting AC voltage into DC voltage for one or two consumers (Rm, Ra), in which circuit a first part of the current is fed to the input side via a large induction coil (L 50 ) and a first rectifier (Gm) and a second part of the current via a second rectifier (Ga) upstream of the large induction coil On the output side, behind the second rectifier (Ga), a switched-mode power supply is arranged, preferably in the form of an up-converter or a flyback converter ( 10 ) The division of the applied current for smoothing the output voltage provides that the induction coil (L 50 ) can be accordingly dimensioned smaller and, despite this, the circuit can also satisfy relevant standard specifications

Thomas Duerbaum

Papers

System for wireless transmission of electrical power, a garment, a system of garments and method for the transmission of signals and/or electrical energy

A detailed analysis of a resonant gate driver for PWM applications

Circuit arrangement for generating a DC-separated output voltage

3-phase solar converter circuit and method

Circuit for converting AC voltage into DC voltage