Amplifier Compensation Circuit for High-Frequency Stray Cancellation

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Solution Overview

Problem

Amplification devices with inductive elements generate triangular high-frequency stray components that harm audio signal quality and cause heating, leading to performance loss when used with audio components like speakers.

Innovation Solution

Incorporating a compensation circuit for each amplification stage with a high-pass filter and inductive elements, connected to the output of the switching circuit of the other stage, to generate a compensation signal that cancels out the stray component, resulting in a cleaner output signal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If an inductive element is used to smooth the switched signal in the amplification stage, then the signal smoothing is improved, but a triangular high-frequency stray component is generated that harms audio signal quality and causes heating

Engineering Contradiction:

Improvesignal smoothingVSAvoidhigh-frequency stray component

Core Design Contradiction:

Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The patent generates a compensation signal using an inductive element that replicates the harmful stray component, then injects this compensation signal in opposite phase to cancel out the original stray component. The harmful high-frequency signal is thus converted into a beneficial cancellation mechanism, eliminating the stray component while preserving the signal smoothing function.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The compensation circuit generates the stray component signal in advance through the inductive element and switches it in opposite phase before it can harm the output signal. By preparing the counteracting signal preliminarily and injecting it at the right moment, the patent prevents the harmful effects of the stray component before they manifest in the final output.

Inventive Principle:

Principle #9Preliminary anti-action

2Power

If the inductive element smooths the switched signal, then the useful component is enhanced, but heating of the amplification device and load occurs causing performance loss

Engineering Contradiction:

Improveuseful signal componentVSAvoidheating

Core Design Contradiction:

PowerVSLoss of energy

Solution Approach 1:

The patent converts the energy that would be lost as heat into a useful compensation signal. By generating and injecting the stray component in opposite phase, the system cancels the harmful high-frequency currents that cause heating, thereby reducing energy loss while maintaining the power amplification function.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

3Object-affected harmful factors

If a compensation circuit is added to reduce the stray component, then audio signal quality is improved, but device complexity increases

Engineering Contradiction:

Improveaudio signal qualityVSAvoidcircuit complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent merges the compensation function with the existing amplification stage by using an inductive element that serves dual purposes: maintaining signal smoothing while generating the compensation signal. The compensation circuit is integrated into the existing topology, sharing components and signals with the main amplification path, thus reducing overall complexity compared to a separate compensation system.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The inductive element in the amplification stage automatically generates the stray component signal that serves as the basis for the compensation signal. The circuit uses its own internally generated signal to create the compensation, rather than requiring an external reference or additional sensing circuitry, thereby simplifying the overall device architecture.

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

The compensation circuit effectively reduces the high-frequency stray component, improving audio signal quality and reducing heating, thereby enhancing the performance and efficiency of the amplification device.

Implementation Method 1

an inductive element connected between the output of the switching circuit and the output of the amplification stage, the inductive element being able to smooth the switched signal generated by the switching circuit

Methodology Applied

Scientific EffectInductance: Inductor

Implementation Method 2

each compensation circuit comprises a high-pass filter

Methodology Applied

Scientific EffectHigh-pass filter: Filter (electronic)

Data Source

PatentUS10797654B2Amplifying device comprising a compensation circuit

Publication Date: 2020.10.06 DEVIALET

AI summary

The present invention relates to an amplification device (10) of an input signal comprising:a first amplification stage (12),a second amplification stage (14),each amplification stage (12, 14) comprising:a switching circuit (22), the switching circuit (22) being able to generate, as output (22A, 22B), a switched signal having at least two states, andan inductive element (24) able to smooth the switched signal to obtain a smoothed signal (I1, I3), the smoothed signal (I1, I3) having a useful component and a stray component.The amplification device (10) further comprises a compensation circuit (16), for each amplification stage (12, 14), able to generate a compensation signal (I2, I4) of the stray component of the smoothed signal (I1, I3) generated in the inductive element (24) of the corresponding amplification stage (12, 14).