Patent ID: 8217589

Claim:
A method for transmitting a control information item from a control device to at least one lamp unit with at least one light-emitting device, the lamp unit having a first and a second supply terminal, the first supply terminal being connected to the neutral conductor of an AC voltage power supply system, the second supply terminal being connected to an output of the control device via a supply line, a first input of the control device being connected to the phase conductor of the AC voltage power supply system, the method comprising: modulating the control information item onto the supply line by the control device during a modulation phase, decoding the control information item, driving the light-emitting device in accordance with the decoded control information item, wherein a switchable shunt is connected between the first and the second supply terminal, at least during the modulation phase, and the shunt has a current-limiting effect and permits only a maximum shunt current.