LED Driver Circuit Series-Parallel Switching for Pushbutton Illumination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing voltage-controlled dimming light emitting diode (LED) driver circuits for pushbutton switches suffer from power inefficiencies, particularly at high input voltages, and lack the ability to operate with direct current (DC) voltages of either polarity.
Innovation Solution
The implementation of a driver circuit that switches six light emitting diodes between series and parallel connections based on input voltage changes, using a rectifier for dual polarity operation, and splitting quiescent current limiting resistance into multiple resistors to enhance power efficiency and compatibility at varying voltage levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single quiescent current limiting resistance is used in the LED driver circuit, then the circuit structure is simple, but power efficiency deteriorates at higher input voltages
Solution Approach 1:
The single quiescent current limiting resistance is divided into multiple resistance elements (first quiescent current limiting resistance and second quiescent current limiting resistance) that can be selectively connected. This segmentation allows the circuit to use different resistance values based on input voltage levels, optimizing power efficiency at higher voltages while maintaining simplicity at lower voltages.
2Device complexity
If the LED driver circuit is designed for single polarity operation, then the circuit design is simplified, but adaptability deteriorates when dual polarity operation is required
Solution Approach 1:
The driver circuit is designed with a bridge rectifier configuration that enables it to accept both positive and negative polarity DC inputs, as well as AC inputs. This multi-functionality allows the same circuit design to operate universally with different input types without requiring separate circuit designs for each polarity.
Solution Approach 2:
The circuit dynamically adapts its operation based on the input polarity and voltage level. The switching mechanism automatically adjusts the connection configuration of the LED strings and resistance elements depending on whether the input is positive or negative polarity, enabling seamless dual polarity operation without manual intervention.
3Device complexity
If four light emitting diodes are used in the driver circuit, then the circuit configuration is simpler, but illumination area and power efficiency at high voltages are limited
Solution Approach 1:
The circuit dynamically reconfigures the LED strings between series and parallel connections based on the input voltage level. At higher voltages, the LEDs are connected in series to utilize the full voltage and improve power efficiency. At lower voltages, they are reconfigured to parallel connections to maintain proper operating current. This dynamic switching enables the circuit to drive more LEDs (six instead of four) while maintaining simplicity in the overall configuration.
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 improves power efficiency at higher voltages, allows illumination with both DC and AC voltages, and maintains dimming compatibility at low voltage levels, effectively addressing the inefficiencies and polarity limitations of prior designs.
Implementation Method 1
Each driver circuit also includes a rectifier allow illumination of the pushbutton switch with direct current voltages of either polarity
Implementation Method 2
a plurality of driver circuits for a six-by-four array of light emitting diodes
Data Source
AI summary
Each driver circuit for a six-by-four array of light emitting diodes illuminating a pushbutton switch switches three pairs of the light emitting diodes between series connection and parallel connection based on changes to an applied input voltage. Driving six light emitting diodes instead of only four allows illumination of a larger area and improves power efficiency at higher applied input voltages, while retaining dimming compatibility at low voltage levels. Each driver circuit also includes a rectifier allow illumination of the pushbutton switch with direct current voltages of either polarity. The quiescent current limiting resistance is split into multiple resistors for further improved power efficiency. Each driver circuit also includes a bridge rectifier to allow illumination of the pushbutton switch with direct current voltages of either polarity or alternating current voltages.