Security monitoring circuit with audio collection and its circuit design method

Abstract

The invention provides a security monitoring circuit with audio collection, and a circuit design method thereof. The collection, transmission and processing of the audio signals are all finished in the form of the original analog signals before the audio signals are inputted into a security monitoring system, so as to ensure the data integrity to the utmost extent. In addition, an active crystal oscillator is used in an analog audio processing module so as to effectively avoid the mutual interference between the clock signals and the other signals, the voice signals after processing are transmitted to a security monitoring device still in the form of the analog voice signals, and from here, the original analog voice signals are subjected to sampling and analog-to-digital conversion for the first time in the security monitoring device, and the obtained digital voice signals are encoded, transmitted and output synchronously with the high-definition video, so that a difficult problem that the security monitoring device only can output the high-definition video, but cannot effectively achieve the output of the in-site high-definition voice of a monitoring picture is effectively solved. Furthermore, a power supply circuit of a power system is subdivided into two independent digital and analog circuits, so that the interference noise of a power supply to the analog and digital signals which are transmitted in the circuit can be effectively reduced.

Description

technical field [0001] The invention relates to an audio sampling circuit, in particular to a security monitoring circuit with audio collection and a circuit design method thereof. Background technique [0002] Traditional monitoring equipment mainly focuses on restoring the video images of the monitoring site, so that some monitoring equipment does not have the ability to capture and collect live voice signals. However, with the promotion of monitoring applications, the importance of audio collection has gradually become prominent. However, in the existing security monitoring field, even devices equipped with voice monitoring can only meet the needs of short-distance voice collection and capture, and voices that are slightly farther away are often either completely unable to capture voice information, or the captured voice information is blurred. Can not effectively distinguish and audio-visual, resulting in incomplete restoration of the monitored scene. [0003] The reas...

AI Technical Summary

Problems solved by technology

However, this solution has several disadvantages: 1) The main control chip of the monitoring equipment itself does not have the audio noise reduction processing capability, so the collected complex audio signals (mainly audio contains environmental noise and useful audio - such as human voice) cannot Properly perform noise reduction processing, so the recorded audio is often noisy and difficult to distinguish useful audio

2) The analog audio signal collected by the microphone is extremely susceptible to interference during circuit transmission, which will also cause the collected sound to be blurred

3) The main control chip of the monitoring equipment itself does not have audio processing capabilities, so there can only be one external microphone, which cannot meet the needs of large-scale monitoring of the monitoring equipment

However, when the main control chip of the monitoring equipment is input, the main control chip needs to re-sample the digital audio signal again, multiple sampling will cause a large distortion of the original audio information, and eventually lead to the loss of weak signals

Therefore, the clarity of the audio signal collected under this scheme is also very limited, which directly reflects that it is impossible to collect audio from a longer distance

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