LED Driver Circuit for Triac Dimming and Voltage Protection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing LED illumination driving circuits face complexity and increased cost due to the need for additional components like dimming control ICs when using triac dimmers, and are susceptible to voltage fluctuations that can damage devices and reduce reliability.
Innovation Solution
A circuit incorporating an AC power supply module, an LED module, a drive IC, a dimming control module, and a linear current adjustment module, which includes a MOS transistor and RC voltage-dividing resistor unit, allows for linear current adjustment and dimming control, ensuring compatibility with triac dimming, 0-10V, and PWM driving by altering the internal reference voltage of the drive IC and controlling the LED module current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a dimming control IC is added to enable triac dimming control, then dimming functionality is achieved, but device complexity and cost increase
Solution Approach 1:
The patent merges the dimming control functionality into the existing drive IC by utilizing its built-in operational amplifier and reference voltage circuit. The dimming control module shares the drive IC's internal resources (operational amplifier, reference voltage generator) rather than adding a separate dimming control IC, thereby achieving triac dimming compatibility while avoiding increased device complexity
Solution Approach 2:
The drive IC is designed to perform multiple functions: constant current control, dimming control, and voltage fluctuation compensation. The operational amplifier within the drive IC serves both as a control element for current regulation and as part of the dimming control circuit, enabling one component to fulfill multiple roles and reducing overall system complexity
2Power
If voltage of external power supply increases, then power delivery capacity improves, but LED beads and driver IC suffer high voltage impact causing damage and reduced reliability
Solution Approach 1:
The patent implements a feedback mechanism where the drive IC continuously monitors the input voltage and adjusts the LED driving current accordingly. When input voltage increases, the drive IC detects this change through its operational amplifier and reference voltage circuit, then automatically reduces the current to maintain constant power delivery, preventing high voltage damage to LED beads and the driver IC
Solution Approach 2:
The drive IC dynamically changes the operating parameters (driving current) in response to input voltage fluctuations. By adjusting the current parameter based on voltage changes, the system maintains safe operating conditions for the LED beads and driver IC while adapting to varying power supply conditions, thus protecting reliability while utilizing available power
3Device complexity
If only LED bead current control is implemented, then simple control is achieved, but linear adjustment rate is insufficient and power balance is poor
Solution Approach 1:
The patent transitions from static current control to dynamic control by introducing a dimming control module that continuously adjusts the driving current based on input voltage changes. The operational amplifier and reference voltage circuit enable real-time dynamic adjustment of the current, improving the linear adjustment rate and power balance while maintaining relatively simple circuit structure through the use of existing drive IC components
Data Source
AI summary
The invention provides a circuit for LED illumination driving current linear adjustment and dimming control. The circuit for LED illumination driving current linear adjustment and dimming control includes AC power supply module, LED module, drive IC, dimming control module and linear current adjustment Module. The linear current adjustment module may control to reduce current flowing through LED module when input voltage is increased, to achieve balance of input power and improve linear adjustment rate thereof; and the dimming control module may alter the change of an internal reference voltage of the drive IC by external input voltage change, thereby realizing the change of the LED module current, cooperating with a holding current driving part, opening and closing a path for the holding current; therefore, the circuit can be applied to triac dimming applications, and the structure is compatible with 0-10V and PWM driving, thereby improving applicability.