Capacitive Speaker Driver Circuit Without Output RC Components

Solution Overview

Problem

Conventional driver circuits for capacitive speakers require capacitors and resistors, which occupy space and increase power consumption, and have limitations in frequency response at low frequencies.

Innovation Solution

A driver circuit with a capacitive load, comprising two output stage circuits and a buffer circuit, that generates voltage signals to drive the capacitive load without the need for capacitors and resistors, optimizing power usage and frequency response.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If capacitors and resistors are disposed between the speaker and output stage of conventional driver circuit, then the speaker can output AC signal with desired volume, but the capacitors and resistors occupy space and cause additional power consumption

Engineering Contradiction:

Improvesignal output capabilityVSAvoidpower consumption

Core Design Contradiction:

ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent extracts and removes the capacitors and resistors from the driver circuit by implementing a capacitive speaker driver circuit that directly drives the capacitive load without requiring these traditional components for AC signal generation and volume control

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The output stage circuit is designed to directly drive the capacitive load, making the circuit universally applicable to capacitive speakers without needing additional capacitors and resistors, thus reducing component count and power consumption

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If capacitors and resistors are disposed in the conventional driver circuit, then the circuit can generate AC signal, but the circuit complexity increases

Engineering Contradiction:

ImproveAC signal generationVSAvoidcircuit complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and removes the capacitors and resistors from the driver circuit by implementing a capacitive speaker driver circuit that directly drives the capacitive load without requiring these traditional components for AC signal generation and volume control

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The output stage circuit is designed to directly drive the capacitive load, merging the functions of AC signal generation and volume control into a single integrated circuit that directly interfaces with the capacitive speaker

Inventive Principle:

Principle #5Merging (Combining)

3Reliability

If conventional driver circuit with capacitors and resistors is used, then the circuit can drive the speaker, but the frequency response at low frequencies is limited

Engineering Contradiction:

Improvespeaker driving capabilityVSAvoidfrequency response range

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The output stage circuit is designed to directly drive the capacitive load, making the circuit universally applicable to capacitive speakers without needing additional capacitors and resistors, thus reducing component count and power consumption

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The circuit uses dynamic voltage signal generation from the output stage to directly drive the capacitive load, enabling improved frequency response including low frequencies by eliminating the restrictive time constants associated with external capacitors and resistors

Inventive Principle:

Principle #15Dynamics

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

The solution eliminates the need for capacitors and resistors, reducing power consumption and enhancing frequency response at low frequencies, resulting in improved sound quality and efficiency.

Implementation Method 1

The first output stage circuit is configured to generate a first voltage signal according to the first audio input signal, a voltage of the first power source and the voltage of the second power source

Methodology Applied

Scientific EffectVoltage signal generation:

Implementation Method 2

The second output stage circuit is configured to generate a second voltage signal according to the second audio input signal, the voltage of the second power source and a voltage of the third power source

Methodology Applied

Scientific EffectVoltage signal generation:

Implementation Method 3

A driver circuit with a capacitive load, comprising two output stage circuits and a buffer circuit, that generates voltage signals to drive the capacitive load

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS11483648B2Driver circuit of capacitive speaker

Publication Date: 2022.10.25 ANPEC ELECTRONICS CORPORATION

AI summary

A driver circuit of a capacitive speaker is provided. Positive and negative power terminals of a first output stage circuit are respectively coupled to a first power source and a second power source. The first output stage circuit outputs a first voltage signal to a first terminal of a capacitive load of the capacitive speaker according to a first audio input signal, a voltage of the first power source and a voltage of the second power source. Positive and negative power terminals of a second output stage circuit are respectively coupled to the second power source and a third power source. The second output stage circuit outputs a second voltage signal to a second terminal of the capacitive load of the capacitive speaker according to a second audio input signal, a voltage of the second power source and a voltage of the third power source.