LED Driving Circuit Color Temperature Control
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Solution Overview
Problem
Existing LED driver circuits face challenges in modulating light to achieve desired color temperatures by combining LED groups with different emission behaviors, particularly in dimming applications, which makes it difficult to easily control color temperature and red tinge.
Innovation Solution
An LED driver circuit that includes multiple LED groups with different color temperatures, connected in series and parallel configurations, and a control unit using MOSFETs and resistors to switch between groups based on rectified output voltage, allowing for precise control of light emission times to manage color temperature and tinge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple LED groups with different color temperatures are combined to achieve desired color temperature control, then color temperature adaptability is improved, but device complexity increases
Solution Approach 1:
The LED lighting system is divided into multiple LED groups (first LED group, second LED group, third LED group) with different color temperatures. Each group can be independently controlled through separate control units, allowing flexible color temperature adjustment by selectively activating different groups based on voltage levels and dimming requirements.
Solution Approach 2:
The control units dynamically switch between different LED groups based on the rectified output voltage level and dimming state. As voltage increases or decreases, the system transitions between groups to maintain optimal color temperature control, creating a dynamic adaptation mechanism that responds to changing operating conditions.
2Stability of the object's composition
If LED groups are switched based on rectified output voltage to control color temperature, then color temperature stability is improved, but control complexity increases
Solution Approach 1:
The control units monitor the rectified output voltage level and use this feedback to determine which LED group should be active. The switching decisions are based on real-time voltage conditions, creating a feedback loop that maintains stable color temperature by adapting to voltage fluctuations and dimming states.
Solution Approach 2:
The system changes the operating parameters (voltage thresholds, activation conditions) of different LED groups based on the rectified output voltage level. By adjusting which groups are active according to voltage parameters, the system maintains color temperature stability across varying operating conditions without requiring complex external control circuits.
3Ease of operation
If the number of first LEDs is made smaller than the number of second LEDs to optimize dimming performance, then dimming quality is improved, but light output balance becomes more difficult to control
Solution Approach 1:
Different LED groups are assigned different quantities of LEDs based on their specific functions. The first LED group has fewer LEDs optimized for dimming states, while the second LED group has more LEDs for brighter states. This local optimization allows each group to excel at its intended operating range while the control system balances the overall output.
Solution Approach 2:
The system dynamically switches between LED groups with different quantities of LEDs depending on the operating state. During dimming, the first group with fewer LEDs provides smooth transitions, while during brighter operation, the second group with more LEDs takes over. This dynamic switching balances light output across different operating conditions.
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
Enables easy setting of desired color temperatures and management of emission color, with the first LED group dominant at low dimming and the second group dominant at high dimming, effectively controlling the red tinge through light emission switching based on voltage increases.
Implementation Method 1
a first phosphor-containing resin region that covers the first LED group, and converts a wavelength of light emitted from the first LED group to emit the light having the first color temperature
Implementation Method 2
a second phosphor-containing resin region that covers the second LED group and the third LED group, and converts a wavelength of light emitted from the second LED group and the third LED group to emit the light having the second color temperature
Data Source
Figure 1
Figure 2(a)~2(c)
Figure 3(a)~3(d)
AI summary
The purpose of the present invention is to provide an LED driving circuit with which it is possible to easily manage the color temperature by adjusting light. An LED driving circuit, characterized in having: a first LED group in which a plurality of first LEDs are serially connected, the first LED group contributing to emission of light having a first color temperature; a second LED group in which a plurality of second LEDs are serially connected, the second LED group contributing to emission of light having a second color temperature; a third LED group in which a plurality of second LEDs are serially connected, the second LED group contributing to emission of light having the second color temperature; and a control unit for switching, in response to an increase in a rectified output voltage, from illumination of only the first LED group to illumination of only the second LED group and then from illumination of only the second LED group to illumination of the second LED group and the third LED group, the number of first LEDs included in the first LED group being less than the number of second LEDs included in the second LED group.