Patent ID: 9307599
Filing Date: 2016-04-05
CPC Classification: F21K,F21S,F21V,F21Y,H01R,H02J,H05B,Y02B

Claim Text:
1. A lighting device comprising: one or more light sources; a primary input power connection for receiving primary power from a primary power supply, for powering at least one of the one or more light sources; a secondary input power connection for receiving secondary power from a secondary power supply, for powering at least one of the one or more light sources; and electronic circuitry coupled to the input power connections and arranged to control power delivery to at least one of the one or more light sources using power received at the input power connections; wherein the electronic circuitry comprises sensing circuitry connected to the primary input power connection and configured to sense an external impedance connected to the primary input power connection and an isolator for isolating the sensing circuitry from other components of the lighting device, the other components of the lighting device being electrically connected to the primary input power connection and presenting a low impedance across the primary input power connection at least when said sensing circuitry is sensing said external impedance.