Control apparatus incorporating a voltage converter for controlling lighting apparatus

A lighting apparatus comprising:

• a buck converter operable to receive an input voltage and generate an output voltage defined between a high voltage rail and a low voltage rail, the high voltage rail and low voltage rail coupled to the output of the buck converter, wherein the buck converter causes the output voltage to be less than the input voltage by increasing the voltage on the low voltage rail;
• at least two LED channels coupled in parallel between the high voltage rail and the low voltage rail, each of the at least two LED channels comprising a switching element coupled in series between the high voltage rail and the low voltage rail, the switching element operable to selectively allow a current to flow through the associated LED channel in response to a channel control signal;
• a control module operable to:
• receive an indication of the current flowing through the buck converter;
• set the output voltage of the buck converter in response to the indication of the current flowing through the buck converter by setting a duty cycle of a voltage control signal provided to the buck converter;
• and
• set the intensity of light output from each of the at least two LED channels by setting a duty cycle of the channel control signals coupled to the switching elements associated with each of the at least two LED channels.

A control apparatus for a lighting apparatus comprising:

• a voltage converter operable to receive an input voltage and generate an output voltage defined between a high voltage rail and a low voltage rail, the high voltage rail and low voltage rail coupled to the output of the voltage converter;
• wherein at least one LED channel is operable to be coupled between the high voltage rail and the low voltage rail;
• and the voltage converter is operable to set the output voltage based at least partially on a voltage control signal by increasing the voltage on the low voltage rail, whereby the output voltage is set to be less than the input voltage;
• a control module operable to:
• receive an indication of the current flowing through the voltage converter;
• and set the output voltage of the voltage converter in response to the indication of the current flowing through the voltage converter by providing the voltage control signal to the voltage converter.