Horn Device Frequency Control for Sound Pressure Stability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The horn device experiences a decrease in sound pressure due to changes in ambient temperature or voltage, causing the vibration frequency of the diaphragm to deviate from the resonance frequency.

Innovation Solution

A horn device with a control system that adjusts the vibration frequency and duty ratio of the coil based on temperature and current measurements to maintain resonance frequency, using a temperature measurement part, current measurement part, power supply device, driving part, and control part to output PWM signals, ensuring consistent sound pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the horn device uses a fixed vibration frequency, then the structure is simple, but the sound pressure decreases when temperature or voltage changes

Engineering Contradiction:
Improvecontrol system complexityVSAvoidsound pressure consistency
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent implements a feedback control system where the control part receives temperature information from the temperature measurement part and current information from the current measurement part, then adjusts the vibration frequency and duty ratio based on this feedback to maintain resonance frequency and prevent sound pressure decrease

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent makes the vibration frequency dynamic by adjusting it according to temperature changes. The control part changes the vibration frequency based on temperature information to track the resonance frequency, transforming a static system into a dynamic adaptive system

Inventive Principle:
Principle #15Dynamics

2Reliability

If the vibration frequency is adjusted according to temperature, then the sound pressure is maintained, but the device complexity increases

Engineering Contradiction:
Improvesound pressure consistencyVSAvoidcontrol system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the vibration frequency parameter according to temperature variations. The control part adjusts the vibration frequency based on temperature information to maintain resonance, and also adjusts the duty ratio based on current information, implementing parameter adaptation to environmental changes

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The horn device performs self-adjustment through the control part that automatically modifies vibration frequency and duty ratio based on temperature and current measurements, enabling the system to self-correct and maintain optimal performance without external intervention

Inventive Principle:
Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Prevents the decrease in sound pressure by maintaining the vibration frequency at the resonance frequency despite changes in ambient temperature or voltage, thereby ensuring consistent sound production.

Implementation Method 1

a temperature measurement part configured to measure a temperature

Methodology Applied
Scientific EffectTemperature measurement:

Implementation Method 2

a current measurement part configured to measure a current value which flows through the coil

Methodology Applied
Scientific EffectCurrent measurement:

Implementation Method 3

the control part is configured to energize the coil and vibrate the diaphragm at a predetermined frequency by magnetic force of the coil

Methodology Applied
Scientific EffectElectromagnetic force: Electromagnetic Induction

Implementation Method 4

resonate by a resonator the sound produced by the vibration to produce sound

Methodology Applied
Scientific EffectResonance: Resonance

Data Source

PatentEP3382690B1Horn device
Publication Date: 2021.04.21 MITSUBA CORP
  • EP3382690B1 patent drawingFigure 1
  • EP3382690B1 patent drawingFigure 2
  • EP3382690B1 patent drawingFigure 3~4

AI summary

A horn device (A, B), which can prevent the decrease of sound pressure is provided. The horn device (A, B) which resonates, by a resonator (1), sound produced by vibrating a diaphragm (21), and comprises a control part (34, 34B) which vibrates the diaphragm (2), and a temperature measurement part (30); the control part (34, 34B) changes a vibration frequency which vibrates the diaphragm (21) according to a temperature measured by the temperature measurement part (30).