Peak Detecting Circuit for Power Factor Correction

Solution Overview

Problem

Existing detecting circuits for power factor correction have slow response times and poor stability, leading to incorrect identification of input voltage variations, especially with asymmetric periodic signals.

Innovation Solution

A peak detecting circuit that generates indication signals based on input voltage, using multiple reference signals and timing circuits to adjust and compare input voltage values, ensuring accurate detection of peak values and minimizing false positives during voltage disturbances.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If existing detecting circuits are used to detect input voltage variations, then the circuit structure is simple, but the response time is slow and stability is poor

Engineering Contradiction:

Improveresponse timeVSAvoidcircuit structure

Core Design Contradiction:

SpeedVSDevice complexity

Solution Approach 1:

The detecting circuit is divided into multiple functional modules: a sampling module that samples the input voltage at specific timing points, a holding module that maintains the sampled voltage value, and a comparison module that compares the held voltage with reference voltages. This segmentation allows each module to perform its function efficiently, achieving fast response time while maintaining reasonable circuit complexity through modular design.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The circuit performs preliminary sampling and holding of the input voltage before comparison operations. The sampling module captures the input voltage at predetermined timing points, and the holding module maintains this sampled value ready for comparison. This preliminary action ensures that when voltage variations occur, the circuit has already prepared the necessary voltage data for immediate comparison, thereby achieving fast response time.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If existing detecting circuits are used, then the circuit structure is simple, but the stability is poor leading to false identification of voltage variations

Engineering Contradiction:

ImprovestabilityVSAvoidcircuit structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The detecting circuit is divided into multiple functional modules: a sampling module that samples the input voltage at specific timing points, a holding module that maintains the sampled voltage value, and a comparison module that compares the held voltage with reference voltages. This segmentation allows each module to perform its function efficiently, achieving fast response time while maintaining reasonable circuit complexity through modular design.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The comparison module compares the held sampled voltage with reference voltages and generates detection results that can be used to adjust the sampling and comparison operations. This feedback mechanism ensures that only genuine voltage variations are detected, improving stability by filtering out false positives while maintaining circuit simplicity through intelligent control logic.

Inventive Principle:

Principle #23Feedback

3Measurement precision

If the sampling interval is set to the period of input voltage, then the peak value detection is accurate, but the response to voltage variations within the period is delayed

Engineering Contradiction:

Improvepeak value detection accuracyVSAvoidresponse speed to voltage variations

Core Design Contradiction:

Measurement precisionVSSpeed

Solution Approach 1:

The circuit performs preliminary sampling and holding of the input voltage before comparison operations. The sampling module captures the input voltage at predetermined timing points, and the holding module maintains this sampled value ready for comparison. This preliminary action ensures that when voltage variations occur, the circuit has already prepared the necessary voltage data for immediate comparison, thereby achieving fast response time.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The sampling module samples the input voltage periodically at specific timing points within each voltage period, capturing peak values accurately. The holding module maintains these sampled values for comparison. This periodic sampling approach ensures both accurate peak detection and the ability to respond to variations between periods, resolving the contradiction between measurement precision and response speed.

Inventive Principle:

Principle #19Periodic action

Data Source

PatentUS20220299546A1Peak detecting circuiit for an input voltage and associated method

Publication Date: 2022.09.22 CHENGDU MONOLITHIC POWER SYST

AI summary

A method for detecting a variation of input voltage. The method is generating an indication signal based on the input voltage, and comparing the input voltage with a first reference signal. The first reference signal is smaller than the indication signal, and if the input voltage is consistently smaller than the first reference signal during a first time duration from the moment when the input voltage is decreased to the first reference signal, the indication signal is decreased after the first time duration.