US 2002/0059008 A1 · Audio system for minimizing the chance that high power audio signals may be directed to a headphone jack

Abstract

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.

Claims20

Dependent claims

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;
and
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.

2 more elements

A system for detecting and compensating a voltage in a headphone, comprising:

a headphone jack having a jack tip contact, a jack ring contact, and a jack sleeve contact adapted to receive a headphone plug having a plug tip, a plug ring, and a plug sleeve;
a power amplifier for generating reference audio signals having a predetermined voltage;
a speaker-headphone control generating a d.c. offset with a predetermined series resistance applied to the jack tip, jack ring, and jack sleeve contacts of the headphone jack, where the speaker headphone control provides a voltage comparison between at least one of the contacts of the headphone jack and the predetermined voltage when the headphone plug is inserted into the headphone jack such that a difference in voltage between the at least one of the contacts of the headphone jack and the predetermined voltage provides a reverse output state;
and
a microprocessor detecting the reverse output state from the speaker headphone control provides a feedback control signal to the power amplifier to adjust the reference audio signal voltages to compensate the audio signal voltages for the headphone.

2 more elements

Dependencies are inferred from the claim text.

Audio system for minimizing the chance that high power audio signals may be directed to a headphone jack

Life of this patent

Audio system for minimizing the chance that high power audio signals may be directed to a headphone jack

Life of this patent

Abstract

Claims20