LED Driving Circuit Dimming Controller Switch Monitoring
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Solution Overview
Problem
Conventional LED driving circuits lack user-adjustable light output, requiring external devices for dimming control and not allowing the dimming controller to remain powered when the power switch is off.
Innovation Solution
A dimming controller that receives a switch monitoring signal to adjust the average current through an LED string, allowing for user-controlled dimming and remaining powered through an illuminated indicator, even when the power switch is off, using a power converter, rectifier, and a current path that includes a power switch, rectifier, and an illuminated indicator.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional LED driving circuit with a power converter and switch is used, then the circuit can power the LED string, but the light output cannot be adjusted by users and requires external dimming devices
Solution Approach 1:
The patent combines the dimming controller functionality directly into the existing power converter circuit. The controller monitors the power switch state and adjusts the average current through the LED string by modifying the power converter's output, eliminating the need for separate external dimming devices while providing user-adjustable light output.
Solution Approach 2:
The power converter circuit is designed to perform multiple functions: it both powers the LED string and provides dimming control capability. The controller uses the existing power switch monitoring signal to regulate light output, making the circuit universal for both driving and dimming operations without requiring additional dedicated components.
2Use of energy by moving object
If the power switch is turned off to save energy, then power consumption is reduced, but the dimming controller cannot maintain settings or remain powered
Solution Approach 1:
The illuminated indicator serves as an intermediary power path. When the power switch is off, current flows through the illuminated indicator to keep the dimming controller powered, allowing it to maintain settings. This intermediary path enables the controller to remain operational without requiring the main power switch to be on.
Solution Approach 2:
The controller monitors the power switch state in advance and prepares dimming settings before the switch is turned off. By measuring the time period between switch off and on states, the controller can adjust the average current accordingly and maintain user preferences across power cycles.
3Adaptability or versatility
If external dimming devices are used to control light output, then dimming functionality is achieved, but additional components increase cost and complexity
Solution Approach 1:
The dimming controller is merged with the power converter circuit, using the existing power switch and current sensing resources. This integration eliminates the need for separate external dimming devices while providing full dimming control functionality through the unified controller that manages both power conversion and light output adjustment.
Solution Approach 2:
The system uses its own internal resources - the power switch monitoring terminal and existing current sensing - to provide dimming control. The controller serves the dual purpose of managing power conversion and implementing dimming functionality without requiring external services or additional components.
Data Source
AI summary
A driving circuit includes a power converter, a dimming controller and a current path coupled to the dimming controller. The power converter receives input power from a rectifier and provides output power to a light source. A power switch transfers power from an AC power source to the rectifier when the power switch is on. The dimming controller receives a switch monitoring signal indicative of the state of the power switch. An average current flowing through the light source has a first value if the power switch is on. The dimming controller is operable for adjusting the average current based on the switch monitoring signal. A current flows from the AC power source through the current path to ground when the power switch is off.