DC-AC Converter Switching Control for Fast Response

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Solution Overview

Problem

Conventional DC-AC converters for LCDs suffer from slow response speed due to simultaneous switching of P-type and N-type transistors, which affects the efficiency of energy transfer and alternating current generation.

Innovation Solution

A DC-AC converter design where each pulse signal output controls the on and off states of a single P-type transistor and a single N-type transistor independently, ensuring they are never switched on simultaneously, enhancing the response speed by preventing parallel capacitance and optimizing the switching of primary windings.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If P-type and N-type transistors are switched on simultaneously in conventional DC-AC converters, then the circuit can provide continuous current flow, but the response speed becomes slow due to parallel capacitance effects

Engineering Contradiction:
Improveresponse speedVSAvoidcontinuous current flow
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent divides the switching operation into separate segments by independently controlling P-type and N-type transistors through different pulse signals. Instead of simultaneous switching, the control circuit applies pulse signals with phase differences, segmenting the switching events in time. This segmentation eliminates parallel capacitance effects while maintaining continuous current flow through sequential operation of transistor pairs.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements periodic switching action by applying pulse signals with specific duty ratios and phase differences. The P-type and N-type transistors are switched in periodic cycles rather than simultaneously, creating a time-separated switching pattern. This periodic action reduces the harmful parallel capacitance effect while ensuring continuous operation through the alternating sequence of transistor activation.

Inventive Principle:
Principle #19Periodic action

2Use of energy by moving object

If simultaneous switching is used in conventional converters, then the circuit structure is simpler, but the energy transfer efficiency is reduced

Engineering Contradiction:
Improveenergy transfer efficiencyVSAvoidswitching control complexity
Core Design Contradiction:
Use of energy by moving objectVSDevice complexity

Solution Approach 1:

The patent employs feedback mechanisms in the control circuit to optimize the switching timing of P-type and N-type transistors. The control circuit monitors the operational state and adjusts the pulse signal phases and duty ratios to achieve optimal energy transfer. This feedback control ensures that the increased switching complexity translates into improved energy efficiency through precise timing control that minimizes losses.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent changes the switching parameters by applying pulse signals with different phase angles and duty ratios to P-type and N-type transistors. Instead of identical simultaneous switching, the control circuit varies the timing parameters to optimize energy transfer efficiency. This parameter modification allows the system to achieve better energy utilization by controlling the exact timing of transistor activation and deactivation.

Inventive Principle:
Principle #35Parameter changes

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

This design significantly improves the response speed and efficiency of the DC-AC converter, allowing for faster switching and improved alternating current generation, addressing the limitations of conventional converters.

Implementation Method 1

a transformation circuit (330) having a plurality of transformers (331, 332). Each transformer (331, 332) is connected to two switching units (321, 322; 323, 324), wherein the P-type and N-type transistors of the two switching units (321, 322; 323, 324) are not switched on simultaneously.

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS7903438B2DC-AC converter with fast response speed
Publication Date: 2011.03.08 INNOCOM TECH (SHENZHEN) CO LTD
  • US7903438B2 patent drawing
  • US7903438B2 patent drawing
  • US7903438B2 patent drawing

AI summary

An exemplary direct current to alternating current converter includes a pulse width modulator having a plurality of pulse signal outputs that can provide a plurality of pulse signals, a driving circuit having a plurality of switching units, and a transformation circuit having a plurality of transformers. Each of the switching units includes a P-type transistor and an N-type transistor. Each pulse signal output is electrically connected to the P-type and N-type transistors of one of the switching units. Each of the transformers is connected to two of the switching units, and the P-type transistors and the N-type transistors of the two switching units are not switched on simultaneously.