Power Supply Circuit for Parallel LED Branches
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Solution Overview
Problem
Existing electronic power supply circuits for LEDs in parallel branches struggle with precise current control, especially when branches have different numbers of LEDs, leading to inefficiencies and potential overcurrent issues during voltage commutations.
Innovation Solution
A power supply circuit with a step-up converter, timer circuit, regulation circuit, and commutation circuit that alternately generates output voltages for each branch, using a single output capacitor and minimizing external components, to prevent overvoltages and control current flow effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single output voltage is used to power multiple parallel LED branches with different LED counts, then the circuit complexity is reduced, but the current control precision deteriorates
Solution Approach 1:
The patent implements periodic action by alternating the power supply between different LED branches in time-division multiplexing manner. The controller switches the connection between branches at different time intervals, allowing each branch to receive dedicated power and feedback control during its active period, thereby achieving precise current control while using a single output voltage source
Solution Approach 2:
The patent applies segmentation by dividing the power supply operation into separate time segments for different LED branches. Each branch is powered and controlled in its own time slot rather than simultaneously, enabling independent current control for each branch while sharing the same power supply circuitry
2Ease of operation
If voltage control is used to regulate current in parallel LED branches, then the ease of operation is improved, but the reliability deteriorates due to unpredictable current values
Solution Approach 1:
The patent implements feedback control by connecting feedback inputs from each LED branch back to the controller. The controller monitors the actual current or voltage in each branch and adjusts the power supply output accordingly to maintain precise control, transforming the open-loop voltage control into a closed-loop system that ensures both ease of operation and reliability
3Measurement precision
If separate feedback inputs are added for each LED branch in SMPS architecture, then the current control precision is improved, but the device complexity increases
Solution Approach 1:
The patent applies universality by designing a single output voltage source and power supply circuit that serves multiple LED branches through time-division multiplexing. The same hardware components (voltage source, controller, feedback circuitry) are reused for controlling different branches at different time intervals, achieving precise control for each branch without requiring separate dedicated power supply circuits for each branch
4Reliability
If the output voltage is oversised to accommodate the worst case of LED voltage differences, then the reliability is improved, but the energy efficiency deteriorates
Solution Approach 1:
The patent implements dynamics by making the output voltage adaptive and dynamic rather than fixed and static. The controller adjusts the output voltage in real-time based on feedback from the active LED branch, allowing the voltage to match the exact requirements of the connected branch. This eliminates the need for oversizing the voltage to accommodate worst-case scenarios, thereby improving energy efficiency while maintaining reliability
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
This solution ensures efficient and precise current control across branches with different LED counts, reducing power dissipation and eliminating peak currents during voltage transitions, thereby enhancing the reliability and performance of the power supply.
Implementation Method 1
a step-up converter (16) connected to the input voltage and able to convert a continuous input voltage (Vbat) into a continuous amplified output voltage (Vout)
Implementation Method 2
the output voltage stored in an output capacitor (18) connected in parallel to the first and second circuit branches (10, 12) to be powered
Data Source
AI summary
An electronic power supply circuit for a load composed of at least two independent circuit branches connected in parallel to each other, where a first branch requires a different power supply voltage from the power supply voltage of a second branch. The circuit includes a step-up converter, a timer circuit connected to the step-up converter so that the converter generates, alternately, at least a first output voltage able to power the first circuit branch and a second output voltage able to power a second circuit branch, a regulation circuit able to regulate the overvoltages at the ends of an output capacitor of the converter during commutations between the different output voltages; and a commutation circuit able to activate the step-up converter, according to the timer signals coming from the timer circuit, when the output voltage at the ends of the output capacitor has reached the level needed to power the activated branch and regulate the current flowing thereto.