Integrated Constant Voltage and Current LED Driver Circuit
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Solution Overview
Problem
Existing LED lighting systems face complexity and inefficiency in controlling current to LEDs, particularly when using bypass switches like MOSFETs or BJTs, necessitating a simpler and more cost-effective approach for managing LED lighting.
Innovation Solution
A driver circuit comprising a rectifier, constant voltage driver, and constant current driver, with a selectively activated switching element and controller, provides a generally constant voltage and current to LEDs, utilizing a floating ground for improved power factor and efficiency, and includes PWM control for adjusting light output.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If bypass switches like MOSFET or BJT are used to control current to LEDs, then current control capability is improved, but device complexity increases
Solution Approach 1:
The patent combines the constant voltage driver and constant current driver into a single integrated circuit device. The constant voltage driver circuit and constant current driver circuit share common components including the switching element (Q1), diode (D1), and capacitor (C1), eliminating the need for separate bypass switches like MOSFET or BJT. This merging reduces device complexity while maintaining both voltage regulation and current control capabilities through the unified driver architecture.
2Measurement precision
If multiple separate driver circuits are used for voltage and current control, then control precision is improved, but device complexity increases
Solution Approach 1:
The patent integrates both constant voltage and constant current control functions into a single driver circuit device. The controller receives feedback from both voltage sensing (through R1 and R2) and current sensing (through sense resistor Rs) and coordinates both control loops within one device. This unified approach maintains precise control of both voltage and current parameters while reducing the overall device complexity compared to using separate driver circuits.
Solution Approach 2:
The patent employs feedback mechanisms in the integrated driver circuit to maintain control precision. The voltage divider network (R1, R2) provides feedback on output voltage to the controller, and the sense resistor Rs provides feedback on output current. The controller uses these feedback signals to regulate both voltage and current precisely within the single integrated device, achieving high control precision without requiring multiple separate circuits.
3Use of energy by moving object
If floating ground is used in constant voltage driver, then power factor is improved, but ease of manufacture worsens
Solution Approach 1:
The integrated driver circuit is designed to accommodate both floating ground and grounded configurations through its universal architecture. The constant voltage driver portion can operate with a floating ground reference to improve power factor, while the constant current driver portion can be grounded to earth for safety. The controller coordinates both portions, allowing the single device to manifest different grounding configurations as needed, thereby improving power factor without significantly complicating manufacturing.
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 offers a cost-effective, efficient, and simplified method for controlling LEDs, enhancing light intensity, hue, color temperature, and uniformity while maintaining constant voltage and current delivery.
Implementation Method 1
The rectifier is connected to the source of incoming AC power and produces a DC voltage
Data Source
AI summary
A driver circuit for delivering a generally constant voltage to a load is disclosed. The driver circuit includes a source of incoming AC power, a rectifier, and a constant voltage driver. The rectifier is connected to the source of incoming AC power and produces a DC voltage. The constant voltage driver receives the DC voltage from the rectifier. The constant voltage driver includes a selectively activated switching element for receiving the DC voltage, a controller, and an output line. The controller receives the DC voltage and is configured to send a drive signal to the switching element in order to activate the switching element. The output line provides the generally constant voltage to the load.