Motor Vehicle Light Power Supply Flicker Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing power supply control devices for motor vehicle light sources using PWM signals are susceptible to input voltage disturbances, leading to significant ripples and undesirable flickering of luminous flux intensity.
Innovation Solution
A device with detection and adaptation means to modify the frequency of a periodic signal controlling the power supply converter, allowing it to adjust to input voltage disturbances and eliminate flickering by comparing the disturbance frequency with a predetermined frequency and modifying the signal accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If PWM signal frequency is used to control light intensity, then luminous flux attenuation function is achieved, but visible flickering occurs under input voltage disturbances
Solution Approach 1:
The patent dynamically adjusts the PWM signal frequency based on detected input voltage disturbance characteristics. The control device continuously monitors input voltage and adapts the PWM frequency in real-time to avoid resonance with disturbance frequencies, thereby eliminating visible flickering while maintaining luminous flux control capability
Solution Approach 2:
The patent implements a feedback mechanism where the input voltage is continuously monitored and the detected disturbance frequency is used to adjust the PWM signal frequency. This closed-loop control ensures that the PWM frequency adapts to changing input conditions, preventing the resonance that causes flickering and maintaining reliable luminous flux control
2Measurement precision
If converter switch frequency is increased to improve output voltage control, then output voltage precision is improved, but sensitivity to input voltage disturbances increases
Solution Approach 1:
The patent employs dynamic frequency adjustment where the converter switch frequency is adapted based on the detected input voltage disturbance characteristics. By continuously monitoring input voltage and adjusting the switching frequency away from disturbance frequencies, the system maintains precise output voltage control while reducing sensitivity to input disturbances
Solution Approach 2:
The patent changes the operating parameters of the converter by adjusting the PWM signal frequency based on detected disturbance characteristics. This parameter adaptation allows the system to operate at optimal frequencies that provide both precise output voltage control and reduced sensitivity to input voltage disturbances
Data Source
Figure 1~2
AI summary
The invention provides a device for controlling the power supply to at least one branch of an electronic circuit comprising at least one light source in a motor vehicle. A converter circuit converts an input voltage VIN into a load voltage (or current) applied to said circuit branch, and control means are configured to control the converter circuit by means of a periodic signal, PWM, having a predetermined frequency f. The frequency f is adjusted in real time and according to any disturbance detected in the input voltage signal VIN, in order to avoid any appearance of flickering in the intensity of the luminous flux emitted by the light sources.