US Patent 8412385 Power management

Communicating a power control feedback signal from a system is disclosed. In some embodiments, upon determining how to control input power which may be based at least in part, for example, on an in situ measurement of an operating condition in an operating environment, an appropriate symbol is constructed based upon the determination and is transmitted on a single line. In some embodiments, the single line corresponds to the reference voltage of an associated power supply.