LED Dimming via Off-Time Voltage Sensing
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Solution Overview
Problem
Existing power supplies for LED lamps that regulate luminous intensity using the Push Button Dimming technique require additional connections and are costly, especially in large installations, as they need a separate line for mains voltage, posing safety risks and being inefficient.
Innovation Solution
A method and device that sense voltage during off-time intervals of switching cycles to update the duty-cycle of PWM modulation, allowing regulation of LED lamp intensity using a single isolated low-voltage bifilar line, with a button-connected resistor or diode to detect user input and adjust the duty-cycle without external synchronization signals, enabling cost-effective and safe luminous intensity control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If additional regulation line connected to mains voltage terminal is provided for Push Button Dimming control, then luminous intensity regulation capability is improved, but device complexity and installation complexity increase
Solution Approach 1:
The patent merges the regulation control function into the existing single isolated low voltage bifilar line already present for LED power supply. The button is connected between the two lines of this existing line pair, eliminating the need for separate regulation wiring. This combines multiple functions (power delivery and regulation control) into a single communication path.
Solution Approach 2:
The single isolated low voltage bifilar line serves multiple functions: it provides power to the LED lamp and simultaneously carries the regulation control signal from the button. This multi-functional use of the existing line pair eliminates the need for dedicated regulation wiring, reducing installation complexity while maintaining full regulation capability.
2Adaptability or versatility
If separate line for mains voltage is installed for regulation control, then regulation functionality is improved, but safety risks increase
Solution Approach 1:
The patent combines the regulation control function into the existing isolated low voltage line, eliminating the need for separate mains voltage wiring for control. All control signals are transmitted through the already-isolated low voltage bifilar line, maintaining safety while enabling full regulation functionality.
3Adaptability or versatility
If intelligent button with microprocessor and remote powering modulator is used, then regulation capability is improved, but cost increases
Solution Approach 1:
The patent implements a self-service regulation system where the button directly controls the power supply's PWM duty cycle through the existing communication line. The power supply itself performs the regulation function by counting off-time intervals and adjusting duty cycle accordingly, eliminating the need for expensive microprocessors and remote powering modulators in each lamp.
Solution Approach 2:
The patent replaces the electronic/microprocessor-based regulation system with a simpler control mechanism. Instead of using intelligent buttons with microprocessors, the system uses a simple button that generates control signals detected by the power supply's existing control circuitry, which then autonomously adjusts PWM parameters to achieve luminous intensity regulation.
Data Source
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AI summary
A method of regulating in switching mode comprising installing an electric bipole between the output terminals of a power supply, the electric bipole having a normally open monostable switch connected in series with a resistive element or with a diode, has been realized. The switching duty-cycle is determined by a control signal generated so as to correspond to at least a voltage value available at the output terminals of the power supply sensed during a present and/or past off-time interval.