Methods and systems for controlling devices via power lines

A method for controlling a device powered by an AC power sine wave, comprising:

• without imposing another or a secondary signal on or with said AC power sine wave, encoding said AC power sine wave such that for each encoded full cycle of AC power sine wave, configuring a half cycle of said one full cycle of said AC power sine wave to have less energy than the other half cycle of said one full cycle, and designating an encoded said full cycle of AC power sine wave having less energy in one of a positive or negative said half cycle as a digital “0”, and designating an encoded said full cycle of AC power sine wave having less energy in the other of said positive or negative said half cycle as a digital “1”,
• encoding a plurality of said full cycles of said AC power sine wave to form a digital character, with a plurality of so-encoded said digital characters forming a command set for controlling operation of said device, each said digital character of said command set associated with a different, discrete operational parameter of said device,
• powering said device using an encoded said AC power sine wave,
• while powering said device using said encoded AC power sine wave, decoding said encoded AC power sine wave,
• changing operation of said device in accordance with a decoded said digital character.