Patent ID: 7451018

Claim:
A control apparatus for a plurality of devices, the control apparatus including respective activation means for activating each of said devices; an electrical power supply arranged to generate an electrical power supply signal for supplying electrical power, wherein each of said activation means is connected to said electrical power supply and arranged to derive electrical power from said electrical power supply signal; means for detecting operation of each device; and means for incorporating signature components into said electrical power supply signal, wherein said detecting means is cooperable with said incorporating means to cause, upon detection by said detecting means that a respective one of said devices has operated, said incorporating means to incorporate a signature component into said electrical power supply signal, said signature component identifying said respective one device, and wherein said signature component incorporating means is arranged to incorporate said signature component into said electrical power signal after a respective time delay has elapsed after the operation of said respective one device has been detected, said respective time delay being initiated by the detection of the operation of said respective one device by the detecting means, and having a length that is different for each of said devices to the extent that, in the event that two or more of said devices operate simultaneously, respective signature components do not interfere with one another.