LED String Driver Circuit with Charge Control Diode

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Solution Overview

Problem

Existing LED lamp control systems require an auxiliary power supply for wireless communication, increasing costs and complexity, and struggle to maintain a stable voltage for shunt switching topologies due to variations in the auxiliary winding voltage.

Innovation Solution

A circuit arrangement with a control circuit, energy storage device, and controllable bypass switch, allowing the control device to operate independently of an external power supply by using energy storage to power the control unit, eliminating the need for an auxiliary winding or converter, and enabling efficient shunt switching.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If an auxiliary power supply is added to power wireless communication chip, then wireless control functionality is achieved, but costs and complexity of power supply design increase

Engineering Contradiction:

Improvewireless control functionalityVSAvoidpower supply design complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines the power supply for the control chip with the LED string power connection. The control chip and its power supply are merged into the existing LED driver circuit, eliminating the need for a separate auxiliary power supply. The control chip is powered directly from the LED string through the driver circuit, integrating multiple functions into a unified design.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The LED driver circuit is designed to serve dual purposes: driving the LED strings and powering the control chip simultaneously. The same power connection that drives the LEDs also provides power to the control electronics, making the power supply system multi-functional and eliminating the need for separate power sources.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If an auxiliary power supply is added to power wireless communication chip, then wireless control functionality is achieved, but costs increase

Engineering Contradiction:

Improvewireless control functionalityVSAvoidmanufacturing cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

Inventive Principle:

Principle #5Merging (Combining)

3Ease of operation

If shunt switching topology is employed with auxiliary winding, then LED channel control is achieved, but voltage stability for control electronics deteriorates due to voltage equilibrium variations

Engineering Contradiction:

ImproveLED channel controlVSAvoidauxiliary supply voltage stability

Core Design Contradiction:

Ease of operationVSStability of the object's composition

Solution Approach 1:

The patent extracts the control electronics power supply from the auxiliary winding and connects it directly to the LED string power source. By taking the control chip power connection directly from the LED string rather than through the transformer auxiliary winding, the design eliminates the voltage stability issues caused by transformer voltage equilibrium variations during shunt switching operations.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces a dedicated power connection path as an intermediary between the LED string and control chip, bypassing the transformer auxiliary winding. This intermediary connection ensures stable voltage supply to the control electronics by directly coupling them to the LED string power source, isolating them from transformer voltage variations.

Inventive Principle:

Principle #24Intermediary (Mediator)

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

This solution reduces costs and complexity by eliminating the need for an auxiliary power supply and maintaining stable voltage for the control unit, enabling efficient control of LED lamps with wireless functionality without additional power sources.

Implementation Method 1

a capacitor C connected in parallel to the control circuit 10

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentEP2829158B1LED string driver circuit including a charge control diode for a capacitor

Publication Date: 2016.05.18 SIGNIFY HOLDING BV

Figure 1
Figure 2

AI summary

The invention relates to a circuit arrangement (1) for controlling at least one load (D1, D2, D3). In order to provide means for extracting an auxiliary power supply from a current source in order to control shunt switching, the inventive circuit arrangement (1) comprises an input terminal (11) for connection to a power supply (30), an output terminal (12) for connection to at least one load element (20, 21, 22, 23), a control circuit (10), comprising a control device (13), which is adapted to control at least one load element (20, 21, 22, 23), and an energy storage device (C), which is adapted to supply power to the control device (13). A controllable bypass switch (M4) is further provided, wherein said bypass switch (M4) and said control circuit (10) are connected in parallel and are connected between said input terminal (11) and said output terminal (12). The circuit arrangement (1) is adapted to operate the bypass switch (M4) to control the power provided to the control circuit.