Driving Device Inductive Control Circuit Reduces Flicker
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Lighting applications using light-emitting elements often suffer from flickering, which can cause eye fatigue and discomfort, especially when the switching frequency is below 60 Hz, as existing solutions fail to effectively mitigate this issue.
Innovation Solution
A driving device comprising a bridge rectifier, inductive control circuit, transformer, power switch element, output stage circuit, and controller, which utilizes Pulse Frequency Modulation (PFM) and Pulse Width Modulation (PWM) operations to adjust inductive current and voltage, thereby reducing non-ideal flicker and eye strain.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the switching frequency of the light-emitting element is increased above 60 Hz to reduce visible flicker, then visible flicker is eliminated, but eye fatigue and discomfort still occur due to non-ideal flicker
Solution Approach 1:
The patent applies periodic action by using Pulse Frequency Modulation (PFM) to vary the switching frequency of the light-emitting element. The controller dynamically adjusts the frequency according to the rectified voltage, creating a periodic modulation pattern that eliminates visible flicker while reducing eye fatigue through controlled frequency variation rather than fixed high-frequency switching
Solution Approach 2:
The patent changes the frequency parameter dynamically using PFM operation. The switching frequency is not fixed but varies periodically according to the rectified voltage level, allowing the system to operate at different frequencies to eliminate both visible flicker and non-ideal flicker effects that cause eye discomfort
2Ease of operation
If the switching frequency is kept below 60 Hz to simplify circuit operation, then circuit operation is simpler, but visible flicker occurs causing eye fatigue and discomfort
Solution Approach 1:
The patent changes the frequency parameter dynamically using PFM operation. The switching frequency is not fixed but varies periodically according to the rectified voltage level, allowing the system to operate at different frequencies to eliminate both visible flicker and non-ideal flicker effects that cause eye discomfort
3Device complexity
If existing driving circuits are used without inductive control, then device complexity is lower, but flicker reduction effectiveness is insufficient
Solution Approach 1:
The patent introduces an inductive control circuit as an intermediary between the rectifier and the light-emitting element. This intermediate stage with inductor and controller enables frequency modulation that effectively reduces flicker, adding necessary complexity to achieve the desired flicker reduction performance
Solution Approach 2:
The controller receives feedback about the rectified voltage and dynamically adjusts the switching frequency accordingly. This feedback mechanism enables the inductive control circuit to adapt to varying conditions and maintain effective flicker reduction across different operating states
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 proposed driving device significantly reduces flicker in light-emitting elements, minimizing eye fatigue and discomfort, while maintaining performance across various electronic devices and frequencies.
Implementation Method 1
The inductive control circuit includes an inductor, and adjusts an inductive current through the inductor according to the rectified voltage and a first control voltage, so as to generate an inductive voltage
Implementation Method 2
The transformer includes a main coil, a secondary coil, and an auxiliary coil. The main coil receives the inductive voltage. The secondary coil generates a transformation voltage
Data Source
AI summary
A driving device for driving a light-emitting element includes a bridge rectifier, a first capacitor, an inductive control circuit, a transformer, a power switch element, an output stage circuit, and a controller. The bridge rectifier generates a rectified voltage. The inductive control circuit includes an inductor, and adjusts an inductive current through the inductor according to the rectified voltage and a first control voltage. The first control voltage is selectively used to perform a PFM (Pulse Frequency Modulation) operation. The transformer generates a transformation voltage according to the inductive voltage of the inductor. The output stage circuit generates an output voltage according to the transformation voltage. The light-emitting element determines whether to generate light according to the output voltage. The controller detects the rectified voltage, and determines the first control voltage according to the rectified voltage.