Abstract: From one aspect the invention provides apparatus for controlling mains electrical circuits including lighting circuits, comprising a remotely controlled receiver unit responsive to received control signals, the receiver unit comprising means for decoding such received control signals in relation to at least two controlled channels for said circuits, means for each channel responsive to plural decoded control signal possibilities for providing signals for the said channel concerned, and selection means associated with the signal providing means for selecting whether or not particular said decoded signal possibilities result in said signals being available and applied to said channel.