LED Driver Circuit Reducing Jitter Under Low Brightness
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Solution Overview
Problem
Existing light fixtures experience current ripples during light adjustments, leading to noticeable jitter and flicker, especially under low brightness conditions, which can be detrimental in applications like stage performances and are difficult to eliminate with current technologies.
Innovation Solution
A device comprising an LED light source, an inductor, a current control module, a switch, and signal control modules that adjust the current flow by disconnecting and reconnecting the switch based on detected current thresholds and PWM signals, optimizing the inductance and input voltage to reduce current change rates and minimize flicker.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If the light fixture adjusts brightness by controlling current flow through the LED light source, then the brightness can be changed, but current ripples are generated causing light jitter and flicker especially under low brightness conditions
Solution Approach 1:
The inductor L is pre-configured in the circuit to store energy in its magnetic field during the switch on-time. This preliminary energy storage action ensures that when the switch turns off, the stored energy can maintain continuous current flow through the LED, preventing current interruptions and ripples that cause flicker and jitter, especially during low brightness adjustments
Solution Approach 2:
The inductor L acts as an intermediary energy storage element between the power supply and the LED light source. It mediates the current flow by storing energy when the switch is on and releasing it when the switch is off, smoothing out current ripples and preventing direct transmission of switching disturbances to the LED, thereby eliminating light jitter and flicker
2Illumination intensity
If the switch is disconnected to reduce current flow and dim the light, then brightness is reduced, but current ripples become more obvious causing increased light jitter
Solution Approach 1:
The inductor L ensures continuous current flow through the LED by maintaining energy storage and release cycles. During PWM dimming operations, the inductor continuously stores energy when the switch is on and releases it when off, preventing current interruptions and maintaining stable current flow even at low brightness levels, thereby ensuring current stability and eliminating light jitter throughout the entire brightness range
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 effectively reduces current ripples and jitter during light adjustments under low brightness, ensuring smoother brightness changes and preventing light flicker, thereby enhancing the stage effect and overall performance.
Implementation Method 1
A second end of the inductor L is connected to an anode of the LED light source... When the switch K1 is connected, the current control module is in non-conducting state, and when the switch K1 is disconnected, the current control module is in conducting state
Data Source
AI summary
A device for reducing jitter of a light source under low brightness is provided. A first end of the switch is for inputting a voltage, and a second end thereof is connected to one end of the inductor. The other end of the inductor is connected to the LED light source. The current control module is connected to the second end of the switch and the first end of the inductor, and a second end of the current control module is grounded. The current acquisition module is used for detecting a current and connected to the signal control module, and sends a current signal into the signal control module according to the current detected. The signal control module is connected to the switch and used for controlling the switch to be disconnected or connected according to the received current signal or a pre-set time threshold.