Control Circuit for Vehicle Lamp Brightness Stability

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Solution Overview

Problem

Existing control circuits for vehicles suffer from flickering lamp brightness due to varying AC voltage from the power generator, especially at low engine rotations, and fail to light the lamp when the generator is not rotating.

Innovation Solution

A control circuit with a first switch for battery charging, a second switch for lamp illumination, and a third switch for battery assistance, using a switch control unit that includes a triangular wave generation circuit, differential amplifier, and comparison circuit to manage the conductive state of the switches based on AC voltage and cycle, ensuring consistent lamp brightness and illumination even at low generator rotations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the lamp is lighted using AC voltage from the power generator, then the lamp can be illuminated, but the brightness flickers when the number of rotations is low

Engineering Contradiction:
Improvelamp brightnessVSAvoidbrightness stability
Core Design Contradiction:
Illumination intensityVSStability of the object's composition

Solution Approach 1:

The battery is charged in advance when the generator produces sufficient voltage, storing energy that is later used to maintain stable lamp brightness during low-rotation periods. The control circuit proactively manages energy storage before the flickering problem occurs.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The battery acts as an intermediary energy source between the generator and the lamp. When generator voltage is insufficient, the battery supplements the power supply, smoothing out voltage fluctuations and preventing brightness flicker.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Illumination intensity

If the power generator does not rotate, then no AC voltage is generated, but the lamp cannot be lighted

Engineering Contradiction:
Improvelamp illuminationVSAvoidoperation under zero rotation
Core Design Contradiction:
Illumination intensityVSAdaptability or versatility

Solution Approach 1:

The battery is charged in advance when the generator is operational, storing energy specifically for use during periods when the generator cannot produce power. This preliminary energy storage enables lamp operation even when the engine is off or the generator is not rotating.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses its own operational periods (when the generator is running) to prepare for non-operational periods (when the generator is not running). The battery charges itself during generator operation, creating a self-sustaining system that ensures continuous lamp capability.

Inventive Principle:
Principle #25Self-service

3Device complexity

If half-wave rectification is used to control battery charging, then the circuit is simple, but the lamp brightness varies with generator rotation speed

Engineering Contradiction:
Improvecircuit complexityVSAvoidlamp brightness consistency
Core Design Contradiction:
Device complexityVSIllumination intensity

Solution Approach 1:

The control circuit proactively monitors generator voltage and manages battery charging in advance, ensuring energy is stored during high-rotation periods for use during low-rotation periods. This forward-looking control prevents brightness variation without requiring complex real-time regulation circuitry.

Inventive Principle:
Principle #10Preliminary action

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 effectively reduces lamp brightness flicker and ensures the lamp remains lit by supplying battery voltage during low generator cycles, maintaining consistent illumination and reducing power consumption.

Implementation Method 1

a power generator that rotates in conjunction with an engine to generate the alternate voltage

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

The control circuit 911 controls a thyristor SCR1 to half-wave rectify the AC voltage VA output from the generator 902 to convert the AC voltage VA into the output voltage VO

Methodology Applied
Scientific EffectRectification: Diode

Data Source

PatentEP2665345B1Control circuit and control method
Publication Date: 2019.08.07 SHINDENGEN ELECTRIC MANUFACTURING CO LTD
  • EP2665345B1 patent drawingFigure 1
  • EP2665345B1 patent drawingFigure 2
  • EP2665345B1 patent drawingFigure 3A~3C

AI summary

A control circuit (20) configured to rectify an alternate voltage output from a power generator, thereby controlling charging of a battery (50) and lighting of a lamp (60), includes: a first switch (21); a second switch (23); and a third switch (25). The first switch is coupled between an output unit of the power generator and the battery. The second switch is coupled between the output of the power generator and the lamp. The third switch is coupled between a connecting point of the first switch and the battery and a connecting point of the second switch and the lamp.