Patent ID: 7385310

Claim:
A method for establishing a connection between a luminaire and an electronic ballast, said luminaire being of a certain type selected from at least two different types of luminaires having different power consumptions where a first type of luminaire has a power consumption which is about an integral multiple of the power consumption of a second type of luminaire, wherein said ballast provides a power supply for the luminaire by supplying a supply voltage, comprising the steps of: prior to supplying said supply voltage to the luminaire, a signal which is not the supply voltage is transmitted from the ballast to the luminaire connected to the ballast; responding to said signal by said luminaire with a response signal which is specific to said certain type; evaluating said response signal to determine said certain type of luminaire connected; and supplying said supply voltage from said power supply to said luminaire only when said luminaire is said certain type which can be supplied by said ballast, wherein said ballast is designed to supply power directly to the second type of luminaire, and at least two identical ballast units are connected in parallel to supply power to the first type of luminaire.