Phase-Cut Dimmable Power Supply with Active PFC and Anti-Interference
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Solution Overview
Problem
Current phase-cut dimming power supplies face limitations such as low efficiency, unsynchronized dimming with LED lamps of different colors, high harmonic content, and high network interference, making them unsuitable for high power applications and LED lamps.
Innovation Solution
A high power factor phase-cut dimming power supply system incorporating an anti-interference circuit, active power factor correction circuit, power conversion circuit, dimmer current maintaining circuit, signal conversion circuit, photoelectric coupler, PWM signal amplifying circuit, and field effect transistor, which ensures high power factor, low harmonic content, and synchronous dimming across various LED colors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a unipolar PFC flyback switching power supply is used to achieve dimming by adjusting limited power, then the power factor is high, but the efficiency is low (generally provides only 80% conversion effect)
Solution Approach 1:
The patent divides the power supply system into separate functional modules: a PFC circuit for power factor correction and a switching power supply circuit for voltage conversion and dimming control. This segmentation allows each module to be optimized independently, achieving high power factor without compromising overall efficiency.
Solution Approach 2:
The patent introduces an intermediary control circuit that coordinates between the PFC circuit and the switching power supply circuit. This intermediary ensures proper timing and control signals are exchanged, enabling both circuits to operate at optimal efficiency while maintaining high power factor.
2Ease of operation
If a phase-cut dimming power supply is used, then the dimming effect is achieved, but the load range is limited (when the load power is lower than 70% of the rated output power, the dimming effect becomes worse)
Solution Approach 1:
The patent implements dynamic control strategies that adapt to varying load conditions. The control circuit automatically adjusts its parameters based on the actual load power, ensuring optimal dimming performance across the entire load range from 10% to 100% of rated output power.
Solution Approach 2:
The patent changes control parameters dynamically based on load conditions. When load power varies, the control circuit adjusts switching frequency, duty cycle, and other parameters to maintain consistent dimming quality throughout the full load range.
3Loss of energy
If a flyback switching power supply or forward switching power supply without a power factor correction circuit is used, then the efficiency is higher and there is no load limit, but the power factor is low (generally ranges from 0.5-0.8) and the harmonic content is extremely high (over 100%)
Solution Approach 1:
The patent merges a PFC circuit with a switching power supply circuit into a unified system. The PFC circuit handles power factor correction while the switching power supply handles voltage conversion, and both work together to achieve high efficiency without compromising power factor or generating excessive harmonics.
Solution Approach 2:
The patent ensures continuous operation of the PFC circuit alongside the switching power supply circuit. This continuous coordinated operation maintains high power factor and low harmonic content throughout the entire dimming range and across all load conditions.
4Device complexity
If an electronic transformer is used for phase-cut dimming, then the circuit is simple, but the ripple is extremely large and the voltage regulation and load regulation are both high, causing damage to LED lamp beads and significant stroboscopic issues
Solution Approach 1:
The patent replaces the simple electronic transformer approach with a modern switching power supply circuit that uses electronic switching and control. This substitution eliminates the large ripple and poor voltage regulation issues while maintaining reasonable circuit complexity through integrated control.
Solution Approach 2:
The patent changes the operating parameters of the power supply circuit, including switching frequency, duty cycle control, and filtering parameters, to minimize ripple and improve voltage regulation. These parameter optimizations ensure reliable LED operation without excessive circuit complexity.
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 achieves high efficiency, high power output, low harmonic content, and improved compatibility with dimmers, enabling seamless operation with LED lamps of different colors and reducing network interference.
Implementation Method 1
photoelectric coupler
Data Source
AI summary
The present invention discloses a high power factor phase-cut dimming power supply system, which includes an alternating current power supply, a phase cutting dimmer, a high power factor phase-cut dimming power supply, an LED lamp, or an LED light. The high power factor phase-cut dimming power supply includes an anti-interference circuit that corresponds to and adaptively connect with each other, an active power factor correction circuit, a power conversion circuit, a dimmer current maintaining circuit, a signal conversion circuit, a photoelectric coupler, a PWM signal amplifying circuit and a field effect transistor. The present invention provides a high power factor phase-cut dimming power supply. It has advantages of a high power factor, a load power without any limitation, a high efficiency, an output power as high as several hundred watts. It can be widely used in the field of high power factor phase-cut dimming power supply.