Abstract: The disclosure relates to a lighting device for frequency-modulated emission. The object to provide a lighting device comprising a light-emitting diode (LED) that allows for higher operating frequencies and that in particular has an improved quality of the emitted light signal is solved in that the lighting device comprises: an LED; a resonant driver circuit with a tuned circuit; wherein the resonant driver circuit is configured to drive the tuned circuit with an operating frequency, and wherein the tuned circuit comprises the LED. The disclosure further relates to a method of operating a lighting device and a use of a lighting device.

Abstract: A circuit for connecting to a dimmer, the circuit configured to receive an input signal from the dimmer. The circuit comprises a first load and a switch. The switch is operable to automatically engage the first load at a predetermined time from a zero-crossing of the input signal and automatically disengage the first load at other times.

Abstract: A method of controlling an electronic ballast for a lighting circuit, the ballast including a bleeder, for use with dimmer circuits, by, in response to a mains supply being connected to the lighting circuit, determining whether a dimmer circuit is present in the lighting circuit; and in response to determining a dimmer circuit is not present, disconnecting the bleeder from the lighting circuit at least until the mains supply is disconnected. The method may be used during start, and the determination of whether a dimmer circuit is present is stored at least until the mains supply is disconnected. Determination of either a leading or trailing edge phase cut dimmer may be made by looking for deviation from the expected sine-wave voltage, either directly through temporal or voltage deviation, or indirectly by examining the second differential of the voltage with respect to time.

Abstract: A method of controlling an electronic ballast for a lighting circuit, the ballast including a bleeder, for use with dimmer circuits, by, in response to a mains supply being connected to the lighting circuit, determining whether a dimmer circuit is present in the lighting circuit; and in response to determining a dimmer circuit is not present, disconnecting the bleeder from the lighting circuit at least until the mains supply is disconnected. The method may be used during, and the determination of whether a dimmer circuit is present is stored at least until the mains supply is disconnected. Determination of either a leading or trailing edge phase cut dimmer may be made by looking for deviation from the expected sine-wave voltage, either directly through temporal or voltage deviation, or indirectly by examining the second differential of the voltage with respect to time.

Abstract: A circuit for connecting to a dimmer, the circuit configured to receive an input signal from the dimmer. The circuit comprises a first load and a switch. The switch is operable to automatically engage the first load at a predetermined time from a zero-crossing of the input signal and automatically disengage the first load at other times.