Abstract: The application relates to a method and system for determining the occupancy of one or more physical spaces. The system comprises one or more charging devices configured to be arranged at the one or more physical spaces, each of the charging devices comprising a charging unit configured for wireless power transfer to a mobile telecommunication device when the mobile telecommunication device is placed in close proximity to the charging unit, a localisation unit configured to broadcast an information signal comprising identifying information of the localisation unit to the mobile telecommunication device; and a controller configured to determine the location of an occupied physical space upon detection of the charging of the mobile telecommunication device, wherein the location is determined based on the broadcast signal.

Abstract: The present invention relates to a Voltage converter (100) for converting an input voltage (V10) to an output voltage (V20) comprising an input circuitry (102) for receiving the input voltage (V10) from a power supply (112), wherein the input circuitry includes chopper means (110) for chopping a voltage (V12) derived from the input voltage (V10) at a chopper frequency to a chopped voltage (V14), an inductive transformer unit (106) for transforming the chopped voltage (V14) to a chopped AC voltage (V16), and an output circuitry (104) for converting the chopped AC voltage (V16) of the inductive transformer unit (106) to the output voltage (V20) having a lower frequency than the chopper frequency.

Abstract: The application relates to a method and system for determining the occupancy of one or more physical spaces. The system comprises one or more charging devices configured to be arranged at the one or more physical spaces, each of the charging devices comprising a charging unit configured for wireless power transfer to a mobile telecommunication device when the mobile telecommunication device is placed in close proximity to the charging unit, a localisation unit configured to broadcast an information signal comprising identifying information of the localisation unit to the mobile telecommunication device; and a controller configured to determine the location of an occupied physical space upon detection of the charging of the mobile telecommunication device, wherein the location is determined based on the broadcast signal.

Abstract: Control circuits (1) bring power converters (4) in different modes in response to detection results. The power converters (4) exchange possibly rectified first voltage/current signals with electronic halogen transformers (2) and supply second voltage/current signals to light emitting diode circuits (5). The first current signals have, in different modes, different amplitudes. The different amplitudes have different constant values and/or different derivative values. As a result, the first current signal has become a relatively varying first current signal. Then, the halogen transformers (2) no longer experience problems that occur when smaller amounts of power need to be provided than designed to. The detections may comprise polarity detections of and/or zero-crossing detections in the first voltage signals. The halogen transformers (2) comprise self-oscillating switched mode power supplies designed to provide first amounts of power at their outputs.

Abstract: Control circuits (1) bring power converters (4) in different modes in response to detection results. The power converters (4) exchange possibly rectified first voltage/current signals with electronic halogen transformers (2) and supply second voltage/current signals to light emitting diode circuits (5). The first current signals have, in different modes, different amplitudes. The different amplitudes have different constant values and/or different derivative values. As a result, the first current signal has become a relatively varying first current signal. Then, the halogen transformers (2) no longer experience problems that occur when smaller amounts of power need to be provided than designed to. The detections may comprise polarity detections of and/or zero-crossing detections in the first voltage signals. The halogen transformers (2) comprise self-oscillating switched mode power supplies designed to provide first amounts of power at their outputs.

Abstract: The invention describes a low-power load arrangement (1) comprising a low-power load (3); a driver (2) for the low-power load (3); connectors (300) for connecting to an electronic transformer (2) realized for converting a mains power supply (4) to a power supply for a normal-power load (5); and a reverse current generating means (LP, SB) realized to provide a reverse current (Irev_LP, Irev_SB) to sustain self-oscillation during operation of the electronic transformer (2), wherein the direction of current flow of the reverse current (Irev_LP, Irev_SB) is opposite in direction to the output current of the electronic transformer (2).

Abstract: Control circuits (1) bring power converters (4) in different modes in response to detection results. The power converters (4) exchange possibly rectified first voltage/current signals with electronic halogen transformers (2) and supply second voltage/current signals to light emitting diode circuits (5). The first current signals have, in different modes, different amplitudes. The different amplitudes have different constant values and/or different derivative values. As a result, the first current signal has become a relatively varying first current signal. Then, the halogen transformers (2) no longer experience problems that occur when smaller amounts of power need to be provided than designed to. The detections may comprise polarity detections of and/or zero-crossing detections in the first voltage signals. The halogen transformers (2) comprise self-oscillating switched mode power supplies designed to provide first amounts of power at their outputs.

Abstract: The invention describes a low-power load arrangement (1) comprising a low-power load (3); a driver (2) for the low-power load (3); connectors (300) for connecting to an electronic transformer (2) realised for converting a mains power supply (4) to a power supply for a normal-power load (5); and a reverse current generating means (LP, SB) realised to provide a reverse current (Irev LP, Irev SB) to sustain self-oscillation during operation of the electronic transformer (2), wherein the direction of current flow of the reverse current (Irev_LP, Irev_SB) is opposite in direction to the output current of the electronic transformer (2).

Abstract: Control circuits (1) bring power converters (4) in different modes in response to detection results. The power converters (4) exchange possibly rectified first voltage/current signals with electronic halogen transformers (2) and supply second voltage/current signals to light emitting diode circuits (5). The first current signals have, in different modes, different amplitudes. The different amplitudes have different constant values and/or different derivative values. As a result, the first current signal has become a relatively varying first current signal. Then, the halogen transformers (2) no longer experience problems that occur when smaller amounts of power need to be provided than designed to. The detections may comprise polarity detections of and/or zero-crossing detections in the first voltage signals. The halogen transformers (2) comprise self-oscillating switched mode power supplies designed to provide first amounts of power at their outputs.

Abstract: The present invention relates to a Voltage converter (100) for converting an input voltage (V10) to an output voltage (V20) comprising an input circuitry (102) for receiving the input voltage (V10) from a power supply (112), wherein the input circuitry includes chopper means (110) for chopping a voltage (V12) derived from the input voltage (V10) at a chopper frequency to a chopped voltage (V14), an inductive transformer unit (106) for transforming the chopped voltage (V14) to a chopped AC voltage (V16), and an output circuitry (104) for converting the chopped AC voltage (V16) of the inductive transformer unit (106) to the output voltage (V20) having a lower frequency than the chopper frequency.

Abstract: A method and a ballast circuit to supply a gas discharge lamp by a high frequency voltage, which, by using a voltage controlled first generator (4), is generated from a substantial sinusoidal mains voltage of a lower mains frequency provided by a main source. A control loop is used which comprises a second generator (10) for providing a reference waveform signal having a frequency of and being synchronized with a supply voltage. The reference signal is compared with a measurement current signal (im), which is representative for a supply current to the lamp, to provide an error signal. The error signal modulates the frequency of the high frequency voltage such that the error signal is minimized.

Abstract: A gas discharge lamp is driven using a high frequency lamp current. A lamp driving circuit comprises a high frequency bridge circuit for supplying said lamp current. To prevent the lamp from extinguishing, when the lamp voltage is lower than a predetermined lamp operation voltage, a resonant circuit is provided in the lamp driving circuit between the lamp and the high frequency bridge circuit. The frequency of the bridge circuit is selected such that the resonant circuit may resonate to sweep up the voltage supplied to the gas discharge lamp to a voltage higher than said lamp operation voltage.

Abstract: To avoid acoustic resonance in a gas discharge lamp, a lamp current constituted of a number of frequencies is supplied to said lamp. Using a number of frequencies, the total power supplied to the lamp is distributed over said number of frequencies. Since the power per frequency is relatively low, the possibility of occurrence of an acoustic resonance is low irrespective of the characteristics of the gas discharge lamp. The current may comprise a number of frequencies by applying a number of sinusoidal currents or by using a non-sinusoidal current.

Abstract: A circuit for measuring the power supplied by a voltage source supplying a sine-shaped voltage by averaging the multiplication of the instantaneous value of the current supplied by the voltage source and a square-wave that is synchronized with the sine-shaped voltage, and by multiplying the result by the actual value of the voltage.

Abstract: A circuit for measuring the power supplied by a voltage source supplying a sine-shaped voltage by averaging the multiplication of the instantaneous value of the current supplied by the voltage source and a square-wave that is synchronized with the sine-shaped voltage, and by multiplying the result by the actual value of the voltage.