Abstract: A LED retrofit driver circuit (3) is provided, comprising at least an input (6) for receiving an operating voltage from a power supply (2), an output (8) for connection to one or more LED units (5), a power converter (7) connected with said input (6) and said output (8) and configured to provide a lamp current (50) at said output (8) during operation in at least a first and a second operating state. To provide a versatile circuit (3), allowing operation with a variety of power supplies and under various load conditions, in said first operating state, the power converter (7) is adapted to switch between a high current generating mode (40), in which the power converter (7) is configured to draw current pulses from said power supply (2) to provide a first average input current (33a), and an OFF mode (42) in which no current is drawn from said power supply (2).

Abstract: A circuit arrangement for controlling the brightness of at least one LED unit is described by the disclosure. The circuit arrangement, in one example, includes an input for receiving a phase-cut operating voltage from a power supply, a signal processor, connected with the input and adapted to provide a dimming signal for the at least one LED unit from the operating voltage. To allow an efficient reduction of noise in the dimming signal but simultaneously to allow an improved dimming of the LED unit, the signal processor are configured to operate at least in a noise suppression mode and a dimming mode. A control device is provided, connected with the signal processor and configured to set the mode of the signal processor in dependence of the variation in the operating voltage.

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: A LED retrofit driver circuit (3) is provided, comprising at least an input (6) for receiving an operating voltage from a power supply (2), an output (8) for connection to one or more LED units (5), a power converter (7) connected with said input (6) and said output (8) and configured to provide a lamp current (50) at said output (8) during operation in at least a first and a second operating state. To provide a versatile circuit (3), allowing operation with a variety of power supplies and under various load conditions, in said first operating state, the power converter (7) is adapted to switch between a high current generating mode (40), in which the power converter (7) is configured to draw current pulses from said power supply (2) to provide a first average input current (33a), and an OFF mode (42) in which no current is drawn from said power supply (2).

Abstract: A lighting device is configured to receive a first voltage signal, and includes: a first circuit coupled to input terminals for receiving the first voltage signal, the first circuit including: rectifying diodes for rectifying the first voltage signal and supplying a second voltage signal, a first capacitor for buffering the second voltage signal, and a second capacitor coupled in parallel to one of the rectifying diodes of the first circuit; a second circuit receiving an input voltage signal, corresponding to the second voltage signal, and converting the input voltage into an output signal; and a light circuit receiving the output signal of the second circuit and including at least one light emitting diode, wherein the first circuit includes a fourth circuit in parallel to the second capacitor, the fourth circuit including at least two fourth circuit diodes and being connected by a fourth capacitor to one of the input terminals.

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: Circuits (1) for receiving output signals from transformers (2) comprise filters (11) and switches (12). In the case of magnetic/electronic transformers, the filters (11) are activated/deactivated, for example for filtering/not filtering unwanted signals coming from converters (4). The filters (11) may comprise capacitors. The switches (12) may comprise fuses. Output signals of magnetic/electronic transformers comprise relatively low/high frequency signals that result in relatively small/large currents flowing through the capacitors, which currents will not blow/blow the fuses. The capacitors, when activated, form, together with leakage inductances of the magnetic transformers, electromagnetic interference filters. Alternatively, the circuits (1) may further comprise detectors (13) for detecting transformer types and for controlling the switches (12) in response to detection results.

Abstract: A circuit arrangement (3, 3?) for controlling the brightness of at least one LED unit (2) is provided, comprising an input (8) for receiving a phase-cut operating voltage from a power supply (4), a signal processor (14, 14?), connected with said input (8) and adapted to provide a dimming signal (12) for said at least one LED unit (2) from said operating voltage. To allow an efficient reduction of noise in the dimming signal (12) but simultaneously to allow an improved dimming of said LED unit (2), said signal processor (14, 14?) is being configured to operate at least in a noise suppression mode (30) and a dimming mode (31). A control device (15, 15?) is provided, connected with said signal processor (14, 14?) and configured to set the mode of said signal processor (14, 14?) in dependence of the variation in said operating voltage.

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: An illumination device (1) comprises: at least one low-power light source (50); a power input stage (20) suitable for receiving AC low voltage from an electronic transformer (ET); a power buffer stage (30) having an input (31) connected to the input stage output (29); a driver (40) for driving the light source and receiving electric power supply from the power buffer stage. The power input stage generates output current pulses for charging the power buffer stage at a relatively low frequency, and during each output current pulse, the power input stage draws input current, the input current always having a current magnitude higher than a minimum load requirement of the electronic transformer.

Abstract: Lighting device suitable for multiple voltage sources, comprising a first circuit (1) with diode circuits coupled to input terminals (2, 3) for receiving first voltage signals from first circuits (21) such as voltage-to-voltage converters. The diode circuits comprise diodes (11-14) for rectifying the first voltage signals and are coupled to output terminals (4, 5) for supplying second voltage signals. First capacitors (15) are coupled to the output terminals (4, 5) for buffering the second voltage signals and for offering buffered second voltage signals to second circuits (22) such as voltage-to-current-converts for feeding light circuits (30) comprising one or more light emitting diodes. Second capacitors (16, 17) coupled in parallel to one of the diodes (11-14) provide a charge-pump effect to improve performances of the first and second circuits (21, 22) and the light circuits (30).

Abstract: Circuits (1) for receiving output signals from transformers (2) comprise filters (11) and switches (12). In the case of magnetic/electronic transformers, the filters (11) are activated/deactivated, for example for filtering/not filtering unwanted signals coming from converters (4). The filters (11) may comprise capacitors. The switches (12) may comprise fuses. Output signals of magnetic/electronic transformers comprise relatively low/high frequency signals that result in relatively small/large currents flowing through the capacitors, which currents will not blow/blow the fuses. The capacitors, when activated, form, together with leakage inductances of the magnetic transformers, electromagnetic interference filters. Alternatively, the circuits (1) may further comprise detectors (13) for detecting transformer types and for controlling the switches (12) in response to detection results.

Abstract: An illumination device (1) comprises: at least one low-power light source (50); a power input stage (20) suitable for receiving AC low voltage from an electronic transformer (ET); a power buffer stage (30) having an input (31) connected to the input stage output (29); a driver (40) for driving the light source and receiving electric power supply from the power buffer stage. The power input stage generates output current pulses for charging the power buffer stage at a relatively low frequency, and during each output current pulse, the power input stage draws input current, the input current always having a current magnitude higher than a minimum load requirement of the electronic transformer.