Sound Card Having Feedback Calibration Loop
AssigneeInternational Business Machines Corporation
InventorJoseph M. Kahan
Life of this patent
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Abstract
A method of, and apparatus for, limiting inputs to and outputs from a computer sound card forms a feedback connection between the input and output of the sound card amplifier. The voltage of the feedback connection is increased from minimum voltage until an over-saturation condition occurs. This finds the “output voltage limit.” Thereafter, the output voltage of the amplifier is restricted to the output voltage limit. The feedback connection is then terminated and the voltage of the signal being supplied to the amplifier is increased from minimum voltage until the over-saturation condition again occurs. This finds the “input voltage limit.” Thereafter, the input supplied to the amplifier is restricted to the input voltage limit.
Claims29
A sound card comprising:
- at least one amplifier having at least one amplifier input and at least one amplifier output;
- at least one sound card input connected to said amplifier input;
- at least one sound card output connected to said amplifier output;
- at least one feedback loop connected to said amplifier input and said amplifier output;
- a feedback controller in said feedback loop;
- and
- at least one input voltage controller connected between said sound card input and said amplifier input.
A sound card comprising:
- at least one amplifier having at least one amplifier input and at least one amplifier output;
- a plurality of sound card inputs connected to said amplifier input;
- a plurality of sound card outputs connected to said amplifier output;
- a plurality of feedback loops, each of feedback loop being connected to a respective pair of said sound card inputs and said sound card outputs;
- a feedback controller in each of said feedback loops;
- and
- at least one input voltage controller connected between said sound card inputs and said amplifier input.
A method of limiting inputs to and outputs from a computer sound card, said method comprising:
- connecting an output of a sound card amplifier to an input of said amplifier using a feedback connection;
- supplying a signal having a frequency to said amplifier;
- increasing voltage of said feedback connection from minimum voltage until an over-saturation condition occurs where harmonics of said frequency begin being output from said amplifier;
- decreasing said voltage of said feedback connection until said harmonics stop being output from said amplifier and recording said voltage as an output voltage limit;
- and
- restricting said output voltage of said amplifier to said output voltage limit.
A method of limiting inputs to and outputs from a computer sound card, said method comprising:
- connecting an output of a sound card amplifier to an input of said amplifier using a feedback connection;
- adjusting an output voltage of said amplifier to maximum voltage;
- supplying a signal having a frequency to said amplifier;
- increasing voltage of said feedback connection from minimum voltage until an over-saturation condition occurs where harmonics of said frequency begin being output from said amplifier;
- decreasing said voltage of said feedback connection until said harmonics stop being output from said amplifier and recording said voltage as an output voltage limit;
- disconnecting said feedback connection;
- restricting said output voltage of said amplifier to said output voltage limit;
- increasing voltage of said signal being supplied to said amplifier from minimum voltage until said over-saturation condition occurs;
- decreasing said voltage of said signal until said harmonics stop being output from said amplifier and recording said voltage as an input voltage limit;
- and
- restricting input supplied to said amplifier to said input voltage limit.
Dependencies are inferred from the claim text.