Audio channel fault detection system
AssigneeHarman International Industries, Incorporated
InventorJeffrey Tackett
Life of this patent
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Abstract
An audio system includes a diagnostic capability to check for faults to a power source and faults to ground for output audio channels configured to drive loudspeakers. The fault to ground analysis involves analysis of a number of digital samples to determine if a predetermined threshold is exceeded during a predetermined period of time. The analysis may involve both a digital signal processor and a microprocessor performing a zero crossing analysis using the predetermined threshold and the predetermined window of time.
Claims24
An audio channel fault detection system comprising:
- a processing device configured to digitally process audio signals;
- and
- a power amplifier coupled with the processing device, the power amplifier configured to amplify audio signals digitally processed by the processing device and output amplified audio signals on an output audio channel to drive a loudspeaker;
- the processing device configured to execute instructions to detect a short to ground event based on samples of alternating electrical current on the output audio channel being greater than a predetermined threshold for a predetermined window of time represented by a plurality of the samples.
A non-transitory computer readable medium that stores instructions executable by a processor to perform audio channel fault detection, the computer readable medium comprising:
- instructions executable with the processor to digitally process an audio input signal and generate a digitally processed audio output signal;
- instructions executable with the processor to supply the digitally processed audio output signal to a power amplifier used to amplify the digitally processed audio output signal;
- instructions executable with the processor to sample an alternating electrical current of the amplified digitally processed audio output signal on an output audio channel of the power amplifier;
- instructions executable with the processor to determine if samples of alternating electrical current on the output audio channel are outside a predetermined threshold for a predetermined period of time;
- and
- instructions executable with the processor to indicate a ground fault event has occurred on the output audio channel in response to the samples of alternating electrical current on the output audio channel being outside the predetermined threshold for the predetermined period of time.
A method of performing audio channel fault detection, the method comprising:
- energizing a power amplifier;
- digitally sampling a feedback electrical current of the power amplifier, the feedback electrical current indicative of an electrical current present on an output audio channel of the power amplifier;
- determining a number of samples between zero crossings of the feedback electrical current;
- and
- identifying a ground fault condition in response to the number of samples between zero crossings being greater than a predetermined value.
Dependencies are inferred from the claim text.