Abstract:
DC Power distribution system The invention relates to a DC power distribution system (1), especially a track lighting system, comprising several power supply units (3) and an electrical consumer (4) like a luminaire electrically connected to an electrical conductor (2)being preferentially a power bar. A power consumption information providing system provides power consumption information and a power supply control system controls the power supply units depending on the provided power consumption information. This allows adapting the DC power distribution to the actually required power, i.e. several power supply units can be electrically connected to the electrical conductor, without providing DC power in an inefficient operation condition. Moreover, the installation of the DC power distribution system can be relatively simple, because the installer just needs to attach a number of power supply units to the electrical conductor, which surely prevents an overload condition, wherein the DC power can still be supplied with high efficiency.
Abstract:
Conversion circuits (1) convert first signals coming from fluorescent ballasts (101) into second signals for light circuits (2) comprising light emitting diodes to replace discharge lamps (102). The conversion circuits (1) comprise input stages (11) with at least two inputs (21-24, 31-32) for receiving the first signals, output stages (13) with two outputs (71-72) for supplying the second signals, and reactive stages (12) for coupling the input and output stages (11, 13). Such relatively simple conversion circuits (1) are relatively low-cost and relatively robust. The reactive stages (12) comprise reactive circuits and reduce amplitudes of one or more of the first and second signals. The reactive circuits comprise one or more inductors (41, 42) and/or capacitors (43).The conversion circuits (1) may form part of the fluorescent ballasts (101) or may form part of the light circuits (2) or may partly form part of the fluorescent ballasts (101) and may partly form part of the light circuits (2).
Abstract:
The invention relates to LED replacement lamp suitable for operation with a high frequency fluorescent lamp ballast, comprising—a LED load (LS) comprising a series arrangement of LEDs, —a first lamp end circuit comprising—a first lamp pin (LP1) and a second lamp pin (LP2) for connection to a first lamp connection terminal comprised in the high frequency fluorescent lamp ballast, —a first rectifier (D1-D4; D1, D2) equipped with at least one input terminal coupled to the second lamp pin and with first and second output terminals coupled to respective ends of the LED load, the first rectifier comprising at least two diodes, one of which is shunted by a first capacitor (C1), —a second lamp end circuit comprising—a third lamp pin (LP3) and a fourth lamp pin (LP4) for connection to a second lamp connection terminal comprised in the high frequency fluorescent lamp ballast, —a second rectifier (D5-D8, D5, D6) equipped with at least one input terminal coupled to the fourth lamp pin and with first and second output terminals coupled to respective ends of the LED load, the second rectifier comprising at least two diodes, one of which is shunted by a second capacitor (C2), wherein the first capacitor and the second capacitor form a series arrangement coupled between the second lamp pin and the fourth lamp pin.
Abstract:
To protect electromagnetic ballasts against damage, driver circuits for coupling the electromagnetic ballasts to light circuits comprising light emitting diodes are provided with rectifier bridges for exchanging first current signals with the electromagnetic ballasts and for providing second current signals to the light circuits, and with protection circuits for protecting the electromagnetic ballasts against parameters of the first current signals obtaining values larger than threshold values. The parameters may be direct-current components of the first current signals and may be average values of rectified versions of the first current signals/peak values of the first current signals. The rectifier bridges may comprise first diode elements. The protection circuits may comprise second diode elements serially coupled to the first diode elements. The protection circuit may comprise average value detectors/peak value detectors and may comprise switches for, in response to detection results, interrupting the second current signals.
Abstract:
The present invention relates to a connection circuit (10) for connecting a driver device (26) to an external power supply (16, 21) for driving a load (28), in particular an LED unit (28) comprising one or more LEDs, comprising: a pair of first input terminals (12, 14) for connecting the connection circuit (10) to an external power supply (16, 21) and for receiving an input voltage (V10, V20) from the external power supply (16, 21), at least one second input terminal (18, 20) for connecting the connection circuit (10) to the external power supply (21) and for receiving an input voltage (V20) from the external power supply (21), a rectifier unit (22) connected to the pair of first input terminals (12, 14) and to the at least one second input terminal (18, 20) for rectifying the input voltage (V10, V20) received from the first input terminals (16, 21) and/or the at least one second input terminal (18, 20) and for providing a rectified voltage (V30) to the driver device (26) for driving the load (28), wherein the at least one second input terminal (18, 20) is connected via a frequency filter (50) to the rectifier unit (22).
Abstract:
According to one embodiment there is provided a lamp device (1) having a lighting module (3) and two pairs of external connection pins (5aa, 5ab, 5ba, 5bb) for connecting the lamp device to a supply voltage of a lighting fixture. A first terminal of the lighting module is connected to a pin of a first pair of pins by a switch which is closed in response to a voltage difference between both the pins of the first pair of pins and the pins of the second pair of pins exceeding a respective threshold voltage. The lamp is therefore safe to handle even in a condition where one pair of pins is connected and the other is not.
Abstract:
Driver circuits (1) for driving loads (2) comprising light emitting diodes are provided with rectifiers (11-14) for exchanging first current signals with fluorescent ballasts (3) such as active electronic ballasts and for supplying second current signals to the loads (2), with switch circuits (21-27) coupled to or forming part of the rectifiers (11-14) for controlling amounts of power supplied to the loads (2), and with controllers (31) for controlling the switch circuits (21-27) such that switching frequencies of the switch circuits (21-27) are equal to or lower than twice the frequencies of the first current signals. Detuning circuits (4) match output impedances of the fluorescent ballasts (3) and input impedances of the rectifiers (11-14). Start-up circuits (5) increase impedances at input terminals of the rectifiers (11-14) at start-up. Current sensors (6) and voltage sensors (7) provide feedback. The controllers (31) synchronize the switching frequencies of the switch circuits (21-27) and switching frequencies of the active electronic ballasts. Detectors (8) detect zero crossings in the first current signals.
Abstract:
Light sources (1) for replacing fluorescent lamps (100) are provided with terminals (11, 12) for exchanging alternating current signals having frequencies of at least kHz with drivers (5), with rectifiers (13) having inputs coupled to the terminals (11, 12) via capacitors (14), and with light emitting diodes (15) coupled to outputs of the rectifiers (13). The rectifiers (13) rectify the alternating current signals and the capacitors (14) provide safety to persons installing the light sources (1). Preferably, the light sources (1) have different ends where the different terminals (11, 12) are located. Each terminal (11, 12) may comprise two pins (21, 22, 23, 24) interconnected via fuses (31,32). Drivers (5) for replacing fluorescent ballasts (500) are provided with inputs (51, 52) to be connected to voltage sources (6)and with outputs (53, 55) for exchanging the alternating current signals with the light sources (1). The drivers (5) may comprise switching circuits (61) for producing the alternating current signals, outputs of the switching circuits (61) being coupled to outputs (53, 55) of the drivers (5) via reactive circuits (62, 63, 66) with inductors (62), capacitors (66) and transformers (63).
Abstract:
The present invention relates to an LED retrofit lamp adapted for operation with an alternating current. The LED lamp comprises an LED unit, first and second switching devices (e.g., first and second relays), a startup voltage supply unit (1010) coupled in parallel to the first switching device, an ignition detection unit (1020) coupled in parallel to the second switching device, and a switch drive unit (1030) for setting the first and second switching devices to a conducting state. If one of the first and second switching devices is shorted either no startup supply voltage or no detection signal is provided, such that the failure is indicated externally to a user.
Abstract:
Light sources (1) for replacing fluorescent lamps (100) are provided with terminals (11, 12) for exchanging alternating current signals having frequencies of at least kHz with drivers (5), with rectifiers (13) having inputs coupled to the terminals (11, 12) via capacitors (14), and with light emitting diodes (15) coupled to outputs of the rectifiers (13). The rectifiers (13) rectify the alternating current signals and the capacitors (14) provide safety to persons installing the light sources (1). Preferably, the light sources (1) have different ends where the different terminals (11, 12) are located. Each terminal (11, 12) may comprise two pins (21, 22, 23, 24) interconnected via fuses (31,32). Drivers (5) for replacing fluorescent ballasts (500) are provided with inputs (51, 52) to be connected to voltage sources (6)and with outputs (53, 55) for exchanging the alternating current signals with the light sources (1). The drivers (5) may comprise switching circuits (61) for producing the alternating current signals, outputs of the switching circuits (61) being coupled to outputs (53, 55) of the drivers (5) via reactive circuits (62, 63, 66) with inductors (62), capacitors (66) and transformers (63).