Pulse waveform modulation circuit

Abstract

The invention discloses a pulse waveform modulation circuit, which comprises a modulation signal input unit (001), a carrier signal input unit (002) and a modulation unit (003), wherein the modulation signal input unit and the carrier signal input unit are modulated by the modulation unit to complete the modulation of the modulation signal input unit. The currently adopted special audio-specific chips and other schemes can meet the standard requirement, but the defects that the hardware cost is relatively high, the modification is inconvenient, and specialized programming is required basically exist. The pulse waveform modulation circuit has the advantages that the requirements of the existing industrial standard on medical alarm sound are met, and the output audio signal includes more harmonic waveforms, so that the sound is gentle, fine and sweet, and is in line with the hearing characteristic of human ears, and thus the hardware cost of the circuit is low, the implementation method is simple, and the standard requirement can be quickly met.

Description

technical field [0001] The invention relates to a pulse waveform modulation circuit. Background technique [0002] At present, in the industry standard of the medical device alarm system, there are detailed requirements on the medical conditions that trigger the sound alarm to the frequency and waveform of the sound alarm. Clinically, when an alarm occurs on a medical alarm instrument, medical staff expect to be able to deduce the urgency, severity, and even level of the alarm from the sound alarm, so as to take corresponding measures to deal with it. However, the standard also requires that the sound should be non-intrusive and non-startling, and that its sound pressure level should under no circumstances exceed that of a medium-priority signal. At present, special audio dedicated chips and other solutions are used. Although they can meet the standard requirements, they basically have high hardware costs, inconvenient modification, and special programming is required. For...

AI Technical Summary

Problems solved by technology

The process of ISD circuit production and implementation, first, the sound needs to be edited through an external sound production tool to complete a sound segment that meets industry standards, and then the sound is played through the speaker and the sound is collected and transcribed to the storage part of the ISD chip through the microphone. The sound clip to be played. Finally, input the playback command and record the playback time for playback. Not only the production and modification time is long, but also the cost is high

The DAC circuit production and implementation process is similar, but the storage location is in the control unit, and the whole picture of the entire sound needs to be simulated to meet the standard requirements. Because it describes the full waveform, there is a large amount of DAC waveform data that needs to be stored and takes up a lot of control units. In short, the cost is high and the modification is inconvenient

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