LED Driver Circuit with Series Controller and Rectifier
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Solution Overview
Problem
Existing LED drivers are expensive due to complexity and electromagnetic compatibility issues, and they require high dielectric strength regulators, which increases costs when operating LEDs with high current consumption and high supply voltages, making them less profitable than incandescent lamps despite reduced energy consumption.
Innovation Solution
A driver circuit designed for sinusoidal AC mains voltage with a rectifier circuit and a controller connected in series, using capacitors or resistors in parallel with the controller to reduce dielectric strength requirements, allowing the use of conventional regulators with low dielectric strength and minimizing heat losses, thus reducing costs and improving efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If clocked LED drivers are used to control LEDs with high current consumption and high supply voltages, then the LEDs can be operated at the required operating point, but the device complexity increases and electromagnetic compatibility becomes problematic
Solution Approach 1:
The patent extracts the switching function from the driver circuit by using the LED's inherent capacitance and the rectifier circuit's natural operation. The controller only needs to control the switching of the rectifier diodes, while the LED's capacitance provides the energy storage function that would otherwise require separate coils and capacitors in a clocked driver.
Solution Approach 2:
The rectifier circuit serves multiple functions: it rectifies the AC voltage, provides energy storage through the LED's capacitance, and controls the LED current. This multi-functionality eliminates the need for separate switching components and energy storage elements required in traditional clocked drivers.
2Object-affected harmful factors
If clocked LED drivers are used to ensure electromagnetic compatibility, then interference suppression can be achieved, but the device complexity and costs increase
Solution Approach 1:
The patent converts the potentially harmful high-voltage switching transients into a beneficial feature by using the LED's inherent capacitance to smooth the current. The rectifier's natural switching behavior, which would normally create EMI, is harnessed to charge the LED's capacitance, providing current regulation without additional switching components that would generate more interference.
3Device complexity
If linear LED drivers are used with high supply voltages, then the circuit structure is simplified, but high demands are placed on the controller's dielectric strength
Solution Approach 1:
The patent uses periodic rectified voltage pulses instead of continuous high voltage. The rectifier circuit converts AC voltage into periodic pulses that naturally charge the LED's capacitance during each half-cycle, reducing the continuous voltage stress on the controller while maintaining adequate current supply during the charging periods.
4Power
If multiple voltage regulators are used in parallel to supply high current with high dielectric strength, then the current requirement is met, but the device complexity and costs increase
Solution Approach 1:
The patent merges the voltage regulation and current supply functions into a single controller that leverages the rectifier circuit and LED capacitance. Instead of using multiple regulators in parallel, one controller manages the rectified voltage pulses, and the LED's capacitance naturally distributes the current supply across multiple LEDs connected in parallel.
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 results in a cost-effective driver circuit that can supply high current to LEDs from high supply voltages, reducing the need for multiple regulators and heat sinks, leading to higher energy efficiency and lower costs, while ensuring the longevity of LEDs by precisely setting their operating point.
Implementation Method 1
a rectifier circuit (26) having at least one controller (40) which is connected in series with the driver output (18) and is designed in such a way to regulate the rectified sinusoidal mains AC voltage (32)
Implementation Method 2
at least one capacitor (50) or at least one resistor (48) or at least one parallel connection of at least one capacitor (50) and at least one resistor (48) which is connected in parallel with the controller (40)
Implementation Method 3
at least one capacitor (50) or at least one resistor (48) or at least one parallel connection of at least one capacitor (50) and at least one resistor (48) which is connected in parallel with the controller (40)
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
The invention relates to a light source (10) with LEDs (14a to 14c) and a driver circuit (12) for supplying the LEDs (14a to 14c) with electricity. The driver circuit (12) is designed for operation with a sinusoidal AC mains voltage (20) and includes a rectifier circuit (26) that rectifies the sinusoidal AC mains voltage (20). Furthermore, the driver circuit (12) has, on the output side of the rectifier circuit (26), a regulator (40) connected in series with the driver output (18), which regulates the rectified sinusoidal AC mains voltage (32) within the range of a defined voltage or current value. The driver circuit (12) further includes a driver output (18) which is connected to the LEDs (14a to 14c) and serves to supply the LEDs (14a to 14c) with a rectified sinusoidal AC mains voltage regulated within the range of a defined voltage or current value.