Supercharge Your Innovation With Domain-Expert AI Agents!

A hand microphone circuit implementation method for anti-whistling automatic gain adjustment for rail transit

An automatic gain adjustment, rail transit technology, applied in the field of communication, can solve the problems of complex hardware circuit, not suitable for car radio, etc., to achieve the effect of automatic adjustment and avoid sound too loud or too small

Active Publication Date: 2022-04-08
天津七一二移动通信有限公司
View PDF6 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] Since we need to suppress the howling phenomenon of the existing vehicle radios and optimize the hand microphones of the vehicle radios, the software method for howling suppression requires not only software algorithms, but also relatively complex hardware circuits, which is not suitable for rail transit vehicles on the radio

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A hand microphone circuit implementation method for anti-whistling automatic gain adjustment for rail transit
  • A hand microphone circuit implementation method for anti-whistling automatic gain adjustment for rail transit
  • A hand microphone circuit implementation method for anti-whistling automatic gain adjustment for rail transit

Examples

Experimental program
Comparison scheme
Effect test

Embodiment Construction

[0038] Such as figure 1 As shown, a hand microphone circuit for anti-howling automatic gain adjustment for rail transit, including a phase shifting circuit, an AGC automatic gain adjustment circuit and an audio amplifier circuit;

[0039] Microphone audio input signal through the phase shift circuit, AGC automatic gain adjustment circuit and audio amplifier circuit in turn to achieve audio output.

[0040] Such as figure 2 As shown, the power circuit:

[0041] This circuit uses 7805LDO regulated power supply chip N1 to convert the DC13.8V provided by the vehicle station to the hand microphone into DC5V to supply power to each device used in this circuit. Such as figure 2 : 13.8V is filtered by the capacitor C3 and then input to pin 1 of the regulated power chip N1, then the 3 pin of the regulated power chip N1 outputs 5V, and is filtered by the capacitor C4 and capacitor C5.

[0042] Such as image 3 As shown, the phase-shifting circuit:

[0043]The electret core with ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention relates to a method for implementing a hand microphone circuit for anti-howling automatic gain adjustment for rail transit, comprising a phase-shifting circuit, an AGC automatic gain adjustment circuit and an audio amplifier circuit; the audio input signal of the microphone core passes through the phase-shifting circuit, the AGC automatic gain in sequence The adjustment circuit and the audio amplifier circuit realize the audio output. The present invention improves the howling problem through the phase-shifting method. The phase-shifting method uses sound waves with the same frequency but different phases to generate interference, resulting in the principle of mutual weakening or even cancellation of the audio frequency, suppressing positive feedback, and using a voltage-limiting chip to output the hand microphone. The audio amplitude is limited to the set voltage, so as to realize automatic gain adjustment and reduce the impact of howling phenomenon.

Description

technical field [0001] The invention relates to the field of communication technology, in particular to a method for implementing a hand-microphone circuit for anti-howling automatic gain adjustment for rail transit. Background technique [0002] In the rail transit wireless communication system, the on-board radio needs to communicate with communication equipment such as handheld stations, dispatching stations, and fixed stations, so there are clear requirements for the indicators of its audio signals. When the driver uses the vehicle-mounted radio to make a voice call with other communication devices, the distance between the hand microphone and the driver's position will affect the audio output of the peer device. When the hand microphone is too close to the driver's position, the hand microphone will output a high-amplitude audio signal, which is prone to clipping distortion and sound distortion after being amplified by the rear stage of the vehicle. [0003] During the...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): H04M9/08H04R3/02H04B1/3822
CPCH04M9/082H04R3/02H04B1/3822
Inventor 杨帅董国军王维史丙臣刘国庆张青平郑彩顺刘佳喜胡林
Owner 天津七一二移动通信有限公司
Features
  • R&D
  • Intellectual Property
  • Life Sciences
  • Materials
  • Tech Scout
Why Patsnap Eureka
  • Unparalleled Data Quality
  • Higher Quality Content
  • 60% Fewer Hallucinations
Social media
Patsnap Eureka Blog
Learn More

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic, Popular Technical Reports.

© 2025 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com