This invention provides a speaker
system that minimizes the number of wires used to provide power and
audio signal to all of the speakers. This is accomplished by without generating interference noises from shared
signal wire implementations. The invention also provides a methodology for reducing power signals from being transmitted to
headphones inserted into a headphone jack. The invention may use four wires to operate the speaker
system. A first wire may be used to provide the
control data signal common and
control power common, and, if a headphone is used, the first wire may also serve as a common ground connection for the earpieces in the headphone. The second wire may provide a substantially
constant current, so that
constant current may be carried in the first wire regardless of the
voltage on the second power / data wire. This way, the first wire may serve as a common control circuitry and the headphone as well. There may be no interference associated with sharing the first wire because
constant current may be provided as a source of power that is independent of the
voltage that appears on the second wire in the
system. If a headphone is used, the current may be substantially constant in the second wire so that the
voltage change in the second wire may not change the voltage in the first wire. Without the voltage change in the first wire, the signals to the headphone is not disturbed.