Power Factor Correction Circuit Using Zero Voltage Edge Detection

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Solution Overview

Problem

Conventional power factor correction circuits face challenges in integrating high-voltage components and suffer from additional power consumption due to the use of resistor elements for voltage detection, making them difficult to integrate and inefficient.

Innovation Solution

A power factor correction circuit that detects zero voltage edge timing to generate a reference clock signal, uses an error amplifier to create an amplification reference signal, and controls a switch based on this signal to synchronize with the input voltage, reducing power consumption through a simple configuration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by stationary object

If a resistor element is used to detect full-wave rectified voltage and generate reference signal, then the reference signal can be generated, but additional power consumption is generated and integration becomes difficult

Engineering Contradiction:

Improvepower consumptionVSAvoidintegration difficulty

Core Design Contradiction:

Use of energy by stationary objectVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the resistor element from the voltage detection circuit. Instead of using a resistor to detect full-wave rectified voltage, the invention uses an operational amplifier-based voltage detector that can operate with much lower power consumption and can be easily integrated into IC circuits.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the passive resistor-based voltage detection mechanism with an active operational amplifier-based detection system. This substitution enables precise voltage detection with minimal power consumption and high integrability, resolving the contradiction between power consumption and integration capability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Difficulty of detecting and measuring

If a resistor element is used to detect full-wave rectified voltage, then voltage detection can be performed, but it is difficult to integrate the power factor correction circuit

Engineering Contradiction:

Improvevoltage detection capabilityVSAvoidintegration difficulty

Core Design Contradiction:

Difficulty of detecting and measuringVSDevice complexity

Solution Approach 1:

The patent removes the resistor element that prevents integration and replaces it with an operational amplifier-based voltage detector. This detector can be fully integrated into IC circuits while maintaining accurate voltage detection capability, thus resolving the integration difficulty.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The operational amplifier-based voltage detector serves multiple functions: it detects voltage, generates reference signals, and can be integrated with other circuit blocks. This multi-functionality reduces the need for separate discrete components, improving integrability while maintaining detection capability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Difficulty of detecting and measuring

If conventional power factor correction circuit is used with resistor element, then voltage detection is achieved, but power consumption increases

Engineering Contradiction:

Improvevoltage detectionVSAvoidpower consumption

Core Design Contradiction:

Difficulty of detecting and measuringVSUse of energy by stationary object

Solution Approach 1:

The patent substitutes the high-power resistor-based detection system with a low-power operational amplifier-based system. The operational amplifier consumes minimal power while providing accurate voltage detection, thus resolving the contradiction between detection capability and power consumption.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the operating parameters of the voltage detection circuit by using operational amplifiers with low power consumption characteristics. This parameter change enables accurate voltage detection while minimizing power consumption, resolving the technical contradiction.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS8148956B2Power factor correction circuit and method of driving the same

Publication Date: 2012.04.03 SEMICON COMPONENTS IND LLC

AI summary

The present invention relates to a power factor correction circuit and a method of driving the power factor correction circuit. The power factor correction circuit according to the present invention includes a power transfer element configured to receive an input voltage, an input current corresponding to the input voltage flowing through the power transfer element, and a switch connected to the power transfer element and configured to control an output voltage generated by the current flowing through the power transfer element. The power factor correction circuit is configured to detect a zero voltage edge timing of the input voltage by detecting the input voltage, generate a reference clock signal having a frequency that varies according to the detected edge timing, generate a reference signal using the reference clock signal, generate an error amplification signal based on a difference between the output voltage and a predetermined error reference signal, generate the amplification reference signal by multiplying the reference signal by the error amplification signal, and control a switching operation of the switch using the amplification reference signal and a detection signal corresponding to a current flowing through the switch.