Abstract: A double ended retrofit LED lighting device having two connecting terminals (L1, L2) at a first end for connection to a power source and two further connecting terminals (R1, R2) at a second end for further connection to said power source, the LED lighting device comprising: —at least one LED (D1) for emitting light, —an LED driver arranged for receiving an AC current from said power source and for driving said at least one LED based on said received AC current, —a filament circuit (RfilL) connected between said two connecting terminals (L1, L2) for supporting a filament current circulating back to said power source for indicating a presence of said LED lighting device to said power source, and—a pin-safety circuit comprising two pin-safety switches (SwLa, SwLb), wherein each pin-safety switch is connected to a respective separate terminal of said two connecting terminals (L1, L2) and comprises a changeover contact, wherein said changeover contact comprises: —a central node (CC) arranged to be connected to sa

Abstract: A lamp comprises an input for connection to a high frequency ballast for gas discharge lamps. A power supply unit obtains power from a LED on voltage of the LED of the lamp, and the power supply unit powers an isolation switch at the input. During a preheat stage of the ballast, the power supply unit does not close the isolation switch, but the isolation switch is closed when the high frequency ballast is in a later state, i.e. the ignition phase.

Abstract: An LED driver that is operable with two different types of power source originally designed for a high-intensity discharge lamp. The LED driver directs current of an input power provided by the power source down a first current path if it is determined that the power source comprises a functional ignitor. The LED driver directs current of an input power provided by the power source down a second current path if it is determined that the 5 power source does not comprise a functional ignitor.

Abstract: A device for determining a type of a power source for powering a LED lighting unit, wherein one possible type comprises a ballast originally designed for a high intensity discharge lamp and repurposed for use with an LED lighting unit. The power source type determiner monitors at least one electrical parameter of either a load or the power source itself after a power drawn by the load whose characteristic is set to a critical value. A value of the electrical parameter is used to identify a type of the power source. A value of the electrical parameter is the pulse generated by the traditional ballast for gas discharge lamp, which pulse is detected to determine the type of the power source.

Abstract: A double ended retrofit LED lighting device having two connecting terminals (L1, L2) at a first end for connection to a power source and two further connecting terminals (R1, R2) at a second end for further connection to said power source, the LED lighting device comprising: —at least one LED (D1) for emitting light, —an LED driver arranged for receiving an AC current from said power source and for driving said at least one LED based on said received AC current, —a filament circuit (RfilL) connected between said two connecting terminals (L1, L2) for supporting a filament current circulating back to said power source for indicating a presence of said LED lighting device to said power source, and—a pin-safety circuit comprising two pin-safety switches (SwLa, SwLb), wherein each pin-safety switch is connected to a respective separate terminal of said two connecting terminals (L1, L2) and comprises a changeover contact, wherein said changeover contact comprises: —a central node (CC) arranged to be connected to sa

Abstract: An LED driver that is operable with two different types of power source originally designed for a high-intensity discharge lamp. The LED driver directs current of an input power provided by the power source down a first current path if it is determined that the power source comprises a functional ignitor. The LED driver directs current of an input power provided by the power source down a second current path if it is determined that the 5 power source does not comprise a functional ignitor.

Abstract: A retrofit Light Emitting Diode, LED, lighting device for connection to a ballast, wherein said ballast is arranged to be connected to a mains voltage and arranged to provide for a ballast current, wherein said LED lighting device is arranged to detect a dip in said mains voltage using a zero current detector.

Abstract: A retrofit Light Emitting Diode, LED, lighting device for connection to a ballast, wherein said ballast is arranged to be connected to a mains voltage and arranged to provide for a ballast current, wherein said LED lighting device is arranged to detect a dip in said mains voltage using a zero current detector.

Abstract: A retrofit lamp is to be used with a ballast. A shunt switch is provided in parallel with an output load and is adapted to shunt input terminals of the lamp using pulse width control so as to tune the current through the lighting element. This current control is used to enable compatibility with different ballasts and to provide dimming control. A detection circuit is used to detect an abnormal drive condition of the retrofit lamp and the pulse width control of the shunt switch can then be overridden by holding the shunt switch at a stable state for a certain duration. This prevents overload conditions and avoids DC signals in the event of component failures.

Abstract: A retrofit lamp is to be used with a ballast. A shunt switch is provided in parallel with an output load and is adapted to shunt input terminals of the lamp using pulse width control so as to tune the current through the lighting element. This current control is used to enable compatibility with different ballasts and to provide dimming control. A detection circuit is used to detect an abnormal drive condition of the retrofit lamp and the pulse width control of the shunt switch can then be overridden by holding the shunt switch at a stable state for a certain duration. This prevents overload conditions and avoids DC signals in the event of component failures.

Abstract: The invention relates to a light emitting device (2) for retrofitting a fluorescent lamp comprising two sets of connecting pins (21, 23, 21?, 23?) for connecting the light emitting system (1) to a lighting fixture, one first (611) and one second (613) filament unit, encapsulated in a bulb and fed through it, electrically coupled to the connecting pins (611, 613) and a solid state light source connected between the filament units.