Patent ID: 7187823

Claim:
A system for transmitting power and an optical signal between components of a surveying instrument, comprising: a first ring core having a first central axis and including a first coil disposed in a first surface of the first ring core, the first coil operable to be connected to a first component in order to receive power from the first component; a second ring core positioned substantially parallel to the first ring core and having a second central axis aligned with the first central axis, the second ring core including a second coil disposed in a second surface adjacent the first surface and positioned a distance from the first coil such that power can be passed from the first coil to the second coil, the second coil operable to be connected to a second component in order to transmit current to the second component, the second ring core further being operable to rotate relative to the first ring transformer about the second central axis; and an optical data link positioned in a central opening in each of the first and second ring cores, the optical data link operable to pass an optical signal between third and forth components of the surveying instrument, the third and fourth components being rotatable with respect to each other.