. . "The remote control units 46 and 48 will each include an onboard power supply, not shown in the drawings, such as a battery, and the controller or processor 62, for each of the remote control units will be operable to manage the operation of the remote control units in such a way that minimum power is consumed except, of course, when one of the switches 46 a, 48 a or 46 b, 48 b is actuated or the r" . .