Patent ID: 7110839

Claim:
A speaker system, comprising: a first wire; a second wire coupled to a current conveyor providing power and data, where the power is generated from a generator that provides a substantially constant current; a microprocessor coupled to the current conveyor, where the microprocessor sends control voltage data to the current conveyor to vary the voltage on the second wire, where the current conveyor outputs a current that is substantially similar to current through the second wire that is substantially independent of the voltage in the second wire; a shunt voltage regulator coupled to the output of the current conveyor and the first wire to shunt excess current through the first wire, and provide a substantially constant voltage to power the microprocessor, where the microprocessor is coupled to a control to detect an adjustment made by a user and based on the adjustment adjusting the control voltage data to the current conveyor to transmit the control voltage data to a data receiver so that the output of the data receiver corresponds in a predetermined way to the control voltage data; third and fourth wires coupled to the generator, where the generator provides opposing polarity audio signal voltages to the third and fourth wires; the third and fourth wires coupled to a speaker-headphone control (SHC), where the SHC produces a d.c. bias voltage in series with a predetermined resistance and applies the voltage to a sleeve conductor of a headphone jack and a first input of a voltage comparator, where the SHC produces a second d.c. bias voltage and applies it to a second input of the voltage comparator, and where the third and fourth wires are coupled to tip and ring connections of the headphone jack so that when a headphone plug is inserted into the headphone jack, the difference between the first and second d.c. bias voltages reverses the polarity compared to the difference prior to insertion of the headphone plug to reverse the output state of the voltage comparator; and the microprocessor detecting the reverse in polarity of the output of the voltage comparator reverses the polarity of the d.c. bias voltages and directs the generator to lower the power level to the third and fourth wires which provide audio signal to a headphone, and directs the generator to make the signals on third and fourth wires to be the left and right channel signals.