Abstract: The present invention relates to an LED retrofit lamp (1) for being connected to a high frequency electronic ballast (26), the high frequency electronic ballast (26) being adapted for providing a voltage and a current to the LED retrofit lamp (1). The LED retrofit lamp (1) comprises an LED unit (4), an adapting unit (30) for adapting the voltage and the current provided by the high frequency electronic ballast (26) to a voltage and a current for operating the LED unit (4), a detecting unit (40) for detecting an electrical value that depends on the current provided by the high frequency electronic ballast (26), and a ballast protection unit (60) for performing, in dependence of the detected electrical value, an operation for protecting the high frequency electronic ballast (26) from an overcurrent situation. This allows avoiding an unsafe situation, such as when the high frequency electronic ballast (26) is overheated.

Abstract: Light sources (1) such as retrofit light emitting diode tubes comprise light circuits (11) with light emitting diodes (12) and feeding electrodes (13, 14), terminals (21-24) for exchanging signals with ballasts (2, 3) or supplies (4, 5), and filament circuits (31, 41) for coupling the terminals (21-24) and the feeding electrodes (13, 14). The filament circuits (31, 41) comprise switch circuits (32) and trigger circuits (33) for in response to presences of frequencies in the signals bringing the switch circuits (32) into conducting modes to introduce relatively low impedances in the filament circuits (31, 41). In non-conducting modes the switch circuits (32) introduce relatively large impedances. This way, in case the light source (1) is connected to a high-frequency ballast (2), the switch circuit (32) is triggered and the light source (1) is normally activated.

Abstract: An LED replacement lamp (20) is described. An LED lighting assembly (40) comprising LED lighting elements is electrically connected to filament emulation circuits, connected to electrical contacts at each of two opposite ends (22a, 22b) of an elongated member. The filament emulation circuits (42) each comprise a first resistor circuit (46) and a second resistor circuit (48) connected to first and second electrical contacts (26a, 24a). The first and second resistor circuits (46, 48) are connected to the LED lighting assembly (40) at a common terminal (50). In order to provide an LED replacement lamp for safe operation even in cases of component failure, and if the replacement lamp (20) is used in incorrect wiring configurations, the first and second resistor circuits (46, 48) each comprise a series connection of at least two resistors, in such a way that in case of failure of one of the resistors, the total resistance of the filament emulation circuits (42) remains above a determined resistance value.

Abstract: The present invention relates to an LED retrofit lamp (700) adapted for operation with an alternating current. The LED lamp comprises an LED unit (740), a mains current line, first and second switching devices (710, 720) (e.g., first and second relays), and a control unit (730). The control unit (730) detects an ignition voltage on the mains current line. In response to detecting the ignition voltage on the mains current line, the control unit (730) sets the first and second switching devices (710, 720) to a conducting state such that the LED unit (740) is connected to power. By using the first and second switching devices (710, 720), safety of the LED lamp (700) is improved, in particular when installing the lamp (700) into a fixture designed for fluorescent lamps.

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) such as retrofit light emitting diode tubes comprise light circuits (11) with light emitting diodes (12) and feeding electrodes (13, 14), terminals (21-24) for exchanging signals with ballasts (2, 3) or supplies (4, 5), and filament circuits (31, 41) for coupling the terminals (21-24) and the feeding electrodes (13, 14). The filament circuits (31, 41) comprise switch circuits (32) and trigger circuits (33) for in response to presences of frequencies in the signals bringing the switch circuits (32) into conducting modes to introduce relatively low impedances in the filament circuits (31, 41). In non-conducting modes the switch circuits (32) introduce relatively large impedances. This way, in case the light source (1) is connected to a high-frequency ballast (2), the switch circuit (32) is triggered and the light source (1) is normally activated.

Abstract: The present invention relates to an LED retrofit lamp (700) adapted for operation with an alternating current. The LED lamp comprises an LED unit (740), a mains current line, first and second switching devices (710, 720) (e.g., first and second relays), and a control unit (730). The control unit (730) detects an ignition voltage on the mains current line. In response to detecting the ignition voltage on the mains current line, the control unit (730) sets the first and second switching devices (710, 720) to a conducting state such that the LED unit (740) is connected to power. By using the first and second switching devices (710, 720), safety of the LED lamp (700) is improved, in particular when installing the lamp (700) into a fixture designed for fluorescent lamps.

Abstract: An LED replacement lamp (20) is described. An LED lighting assembly (40) comprising LED lighting elements is electrically connected to filament emulation circuits, connected to electrical contacts at each of two opposite ends (22a, 22b) of an elongated member. The filament emulation circuits (42) each comprise a first resistor circuit (46) and a second resistor circuit (48) connected to first and second electrical contacts (26a, 24a). The first and second resistor circuits (46, 48) are connected to the LED lighting assembly (40) at a common terminal (50). In order to provide an LED replacement lamp for safe operation even in cases of component failure, and if the replacement lamp (20) is used in incorrect wiring configurations, the first and second resistor circuits (46, 48) each comprise a series connection of at least two resistors, in such a way that in case of failure of one of the resistors, the total resistance of the filament emulation circuits (42) remains above a determined resistance value.

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: The present invention relates to an LED retrofit lamp (1) for being connected to a high frequency electronic ballast (26), the high frequency electronic ballast (26) being adapted for providing a voltage and a current to the LED retrofit lamp (1). The LED retrofit lamp (1) comprises an LED unit (4), an adapting unit (30) for adapting the voltage and the current provided by the high frequency electronic ballast (26) to a voltage and a current for operating the LED unit (4), a detecting unit (40) for detecting an electrical value that depends on the current provided by the high frequency electronic ballast (26), and a ballast protection unit (60) for performing, in dependence of the detected electrical value, an operation for protecting the high frequency electronic ballast (26) from an overcurrent situation. This allows avoiding an unsafe situation, such as when the high frequency electronic ballast (26) is overheated.