Abstract: A driver circuit for operating one or more light emitting diodes(LEDs) is disclosed. An alternating supply current is generated and transformed to an alternating secondary winding voltage. Using rectifier means, such as diodes or synchronous switches, the alternating secondary winding voltage is converted to a substantially constant load current by using a buffer element. The buffer element comprises an output choke, such as an inductor. The power transferred from the power source to the LEDs may be controlled by frequency control of the alternating supply current.

Abstract: A light generating device (20) comprises: —an input for receiving a DC input voltage (Vin) of varying magnitude; —a controllable current source (40); —a switch matrix (30) comprising a plurality of controllable switches (S1-SN); —a plurality of n LEDs (D1, D2, . . . Dn) connected to output terminals of the switch matrix (30); —a controller (50) controlling said switches and controlling the current generated by the current source dependent on the momentary value of the DC input voltage (Vin). The controller is capable of operating in at least three different control states. In a first control state all LEDs are connected in parallel. In a second control state all LEDs are connected in series. In a third control state at least two of said LEDs are connected in parallel while also at least two of said LEDs are connected in series.

Abstract: A light generating device (20) comprises: —a rectifier (23) rectifying an AC input voltage and providing a rectified AC output voltage (Vin); —a controllable current source (40); —a switch matrix (30) comprising a plurality of controllable switches (S1-SN); —a plurality of n LEDs (D1, D2, . . . Dn) connected to output terminals of the switch matrix (30); —a controller (50) controlling said switches and controlling the current generated by the current source dependent on the momentary value of the rectified voltage (Vin). The controller is capable of operating in at least three different control states. In a first control state all LEDs are connected in parallel. In a second control state all LEDs are connected in series. In a third control state at least two of said LEDs are connected in parallel while also at least two of said LEDs are connected in series.

Abstract: The present invention relates to a harmonic compensation circuit for compensating at least the third harmonic in the input current (Imains) drawn by an LED light source (1) from a mains voltage supply (2), comprising: a signal input (21, 22) for receiving a first input signal proportional to the input voltage (Vin) of said LED light source (1) and a second input signal (Vsh) proportional to the LED current (ILED) of said LED light source (1), a signal output (25) for outputting a compensation current (Icomp), a processing unit (24a, 24b) for comparing said second input signal (Vsh) to a reference signal (VRb, VR7) and for generating said compensation current (Icomp) based on said comparison, the sum of said compensation current (Icomp) and said LED current (ILED) being proportional to the input voltage (Vin) of said LED light source (1) and said compensation current (Icomp) being provided for minimizing at least the third harmonic in the input current (Imains) drawn by said LED light source (1) from said main

Abstract: Recently, the use of class-D audio amplifiers has become more and more widespread. In contrast to the generally employed class-AB linear amplification technology, class-D allows for improved efficiency. However, the class-D principle is known for its poor distortion characteristics. According to the present invention a digital amplifier (18) is provided for converting an audio signal to a power output, comprising a ripple suppression circuit (16) for suppressing voltage ripples in a supply voltage supplied to the bridge circuit with (6) at least one pair of switches. The ripple suppression circuit (16) suppresses ripples in the supply voltage supplied to a switch in the bridge circuit (6), which has been found to cause a major part of the distortions in the output signal of the digital amplifier (18).

Abstract: The present invention relates to a device and method for controlling the color point of an LED light source (50). Color point control is a most interesting product feature both for white and colored LED light sources. In known methods for the color control of RGB LED light sources use is made of flux and color sensors. However, there are difficulties with respect to sensing quickly changing ambient light, deeply dimmed colors, coordinating the measurements with the switching of the LEDs, and controlling the color in LED light units comprising a number of independent LED lamps, e.g. segmented wall washers and LCD backlights. It is proposed according to the present invention to control the color of the LED light source (50), using a model-based feed forward approach. Factors relating the parameters controlling the LED currents to the brightness for the different colors (and segments) are stored and used for open loop control. A slow-running procedure continuously measures and updates these factors.

Abstract: A Wireless power transmission system comprises a base unit (1) with multiple magnetic field generator circuits and a device (10), separable from said base unit (1) having a receiving inductor, adapted to receive power inductively when said device (10) is in proximity to one of said generator circuits, wherein said base unit (1) comprises a controller (3), configured to determine a transmission circuit (2?) from said generator circuits when said receiving inductor is in proximity to said transmission circuit (2?), whereupon said transmission circuit (2?) is operated to generate a first magnetic field (8), having a first phase, to induce a current in said receiving inductor and at least one of the remaining generator circuits is operated as a compensation circuit (2?, 52, 82) to generate a second magnetic field (21), having an opposite phase to said first phase.

Abstract: An average power consumption of receiving units (3,5,7) for controlling apparatuses (4,6,8) in response to operation control signals from transmitting units (2) may be reduced by introducing devices (1,21) for controlling the power consumption of the receiving units (3,5,7) in response to detections of states of the apparatuses (4,6,8). The devices (1) may comprise controllers (30) for controlling the power consumption in a wireless, non-wireless, physical and/or logical manner. The devices (1) may comprise monitors (33) for monitoring power consumption, currents and/or voltages at the receiving units (3,5,7) and/or the apparatuses (4,6,8).

Abstract: An input stage (10) of an apparatus (1) for driving a light-emitting diode (40-42) receives a signal from a power supply (30-32), and an output stage (20) supplies a current to the light-emitting diode (40-42). The peak value divided by the average value of the current forms a ratio. The driving efficiency is improved by providing the input stage (10) with an arrangement (11) for reducing this ratio by manipulation of the signal, without the necessity of using any smoothing capacitors/inductors. The manipulation may comprise an addition of a frequency component to the signal or an adaptation of an amplitude of a frequency component of the signal. This frequency component may be a third and/or fifth and/or seventh harmonic frequency component of a fundamental frequency component of the signal. The arrangement (11) may comprise a resonant tank which may need to be tuned to the frequency component of the signal.

Abstract: Adaptation circuits (3) for controlling conversion circuits (1-2) for converting input signals into pulse signals and for converting pulse signals into output signals are provided with generators (30) for generating control signals in dependence of input signals and (basic idea) with compensation circuits (71-72, 81-83) for adjusting the generators (30) in dependence of input information for increasing a stability of output signals, to be able to supply relatively constant output signals to loads (6). The adaptation circuits (3) may reduce dependencies between input signals and output signals and may generate control signals independently from output signals to avoid feedback loops.

Abstract: The invention relates to an illuminated tiling system (100) which comprises back panels (10) with at least one electrically conductive layer (12, 13), plugs (20) with projections (21, 23) that electrically contact the conductive layer(s) (12, 13), and light-tiles (30) with (O)LEDs that can be fixed to the plugs. For an easy tiling, dummy-tiles can first be tiled together with conventional tiles (2) and later be replaced with the light-tiles (30).

Abstract: A method for manufacturing a flooring product with integrated circuitry, comprising the steps of providing a plurality of pieces (6), stacking said pieces on top of each other, displaced in relation to each other to form an offset stack (10), and compressing said offset stack to form said flooring product. The method further comprises arranging flexible circuitry (7) on an upper surface of at least one piece, so that, when said pieces are stacked, a first portion (7a) of flexible circuitry on the at least one piece is exposed, said first portion (7a) including circuitry for interacting with the environment. By arranging the circuitry in the flooring during such a manufacturing process, a flooring product is achieved where only a portion of the circuitry is exposed, and another portion is embedded in the flooring.

Abstract: Driving a lighting device by a driving circuit for providing driving power for driving a lighting device, and by a decoupling unit for electrically decoupling the driving circuit from a lighting circuit. The driving power is transferred at least partially from the driving circuit to the lighting circuit, and the lighting device is arranged within the lighting circuit such that its anode is at ground potential of the driving circuit.

Abstract: In supply circuits (6) comprising bridge circuits (2) and resonance circuits (3) with primary parts to be coupled to the bridge circuits (2) and secondary parts to be coupled to load circuits (4), the secondary parts are provided with elements (32-34) defining resonance frequencies and resonance impedances, to be able to supply different load circuits (4) and/or different loads (41-42) per load circuit (4) individually. The elements (32-34) may comprise capacitors (34) and inductors (32-33). The resonance frequencies define features of primary signals to be supplied from the bridge circuits (2) to the resonance circuits (3) such as pulse widths of pulses of voltage signals and/or pulse frequencies of the voltage signals. The resonance impedances define features of secondary signals to be supplied from the resonance circuits (3) to the load circuits (4) such as values or average values of current signals.

Abstract: Resonant gate driver circuits provide for efficient switching of, for example, a MOSFET. However, often an operation of the resonant gate driver circuit does not allow for an application where high switching frequencies are required. According to the present invention, a pre-charging of the inductor of the resonant gate driver circuit is performed. This allows for a highly efficient and fast operation of the MOSFETs.

Abstract: In a method and a driver circuit for operating one or more light emitting diodes, LEDs, an alternating supply current is generated and transformed to an alternating secondary winding voltage. Using rectifier means, such as diodes or synchronous switches, the alternating secondary winding voltage is converted to a substantially constant load current by using a buffer element, such as an output choke, i.e. a suitable inductor. The power transferred from the power source to the LEDs may be controlled by frequency control of the alternating supply current.

Abstract: The invention relates to a lighting device that may particularly be used as an LCD backlight and that comprises an array of light emitters (11.1, 11.2) which are optionally separated by optical barriers (13). The light emitters (11.1, 11.2) may particularly be realized by groups of LEDs (12.1, 12.2) of different colors, for example red, green and blue. Local control units (16), driving units (15.1, 15.2), and sensor units (14) are provided to control the individual light output of the light emitters, wherein at least one of these components is shared by two or more light emitters (11.1, 11.2).

Abstract: Operating a lighting device by acquiring a target brightness level of at least one solid-state lighting unit, and determining a reference driving current amplitude for obtaining the target brightness level. If the reference driving current amplitude is below an optimum driving current amplitude, the solid-state lighting unit is operated at the optimum driving current amplitude, which is pulse-width modulated to obtain the target brightness level.

Abstract: The present invention relates to a low cost LED driver module comprising a switched-mode power supply (smps) having down-converting characteristics (11) which is controlled by a comparator (31). The comparator is hysteresis configured, which reduces ripple and transients in the LED current, and the module can be accomplished with inexpensive standard components.

Abstract: The invention relates to a standby circuit, an electrical device with a standby circuit, a method for the control of the electrical device and a power supply assembly. Whereas the power supply unit and the control electronics are in permanent operation when conventional devices are in the standby mode and consequently have a high power consumption, the invention proposes a solution for saving energy while retaining convenience of operation by which the power supply unit is switched off in the standby mode. A standby circuit, preferably fed by an energy buffer element, remains active in the standby mode and monitors signal inputs for activation events. When an activation event occurs, the standby circuit switches on the power supply unit.