Solar LED Lamp Control Circuit for Ultra-Low Power Battery Protection

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Solution Overview

Problem

Conventional solar powered street lighting systems fail to provide continuous lighting during rainy days due to incorrect solar panel orientation, inefficient battery utilization, excessive energy consumption by the control unit for DC-AC-DC conversions, and integration of mismatching subsystems, leading to insufficient energy storage and delivery.

Innovation Solution

The control unit is designed to operate directly in DC form without converters or regulators, performing only switching functions to minimize energy consumption, and the LED lamps are designed to use the full battery voltage range without DC-AC-DC conversions, ensuring efficient energy storage and utilization, while the control box focuses on switching functions to conserve energy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If DC-AC-DC conversions and voltage regulation are performed continuously by the control unit, then battery protection and energy management are achieved, but energy consumption increases significantly

Engineering Contradiction:
Improvebattery protectionVSAvoidcontrol unit energy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The patent extracts and removes the DC-AC-DC conversion and voltage regulation functions from the control unit, keeping only the essential switching and protection functions. This reduces the control unit's energy consumption significantly while maintaining battery protection capabilities through simplified voltage threshold detection and switching control.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The system uses the inherent electrical characteristics of the battery and circuit elements to provide self-protection. The control unit monitors voltage thresholds and automatically switches connections without active regulation, allowing the system to self-regulate energy flow based on predefined voltage limits, reducing the need for continuous active control.

Inventive Principle:
Principle #25Self-service

2Ease of manufacture

If solar panels are oriented incorrectly, then installation is simplified, but energy collection efficiency decreases significantly

Engineering Contradiction:
Improveinstallation simplicityVSAvoidsolar energy collection
Core Design Contradiction:
Ease of manufactureVSUse of energy by moving object

Solution Approach 1:

The patent adjusts the system's energy balance parameters to accommodate suboptimal solar panel orientation. By optimizing other system parameters such as battery capacity, LED lamp efficiency, and reducing control unit consumption, the system compensates for the reduced solar energy collection, allowing installation without precise orientation while maintaining operational reliability.

Inventive Principle:
Principle #35Parameter changes

3Duration of action of stationary object

If only partial battery voltage range is utilized, then battery lifespan is extended, but available energy for lighting is reduced

Engineering Contradiction:
Improvebattery lifespanVSAvoidavailable energy
Core Design Contradiction:
Duration of action of stationary objectVSQuantity of substance

Solution Approach 1:

The control unit implements voltage threshold monitoring with feedback control. It detects when battery voltage reaches predefined thresholds and automatically switches charging or discharging connections, enabling the system to safely utilize the full battery voltage range. This feedback mechanism prevents overcharging and over-discharging, extending battery lifespan while maximizing available energy storage and delivery.

Inventive Principle:
Principle #23Feedback

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 design significantly reduces energy consumption, allowing the system to provide extra lighting stamina on long dark days, utilizing the full energy storage capacity and preventing battery overcharging or over-draining, thus enabling continuous lighting for more than three days with minimal solar input.

Implementation Method 1

Solar powered street lighting systems receive solar energy from the sun in the form of light. The light photons are converted into electricity by a solar panel.

Methodology Applied
Scientific EffectPhotovoltaic effect: Photovoltaic Effect

Data Source

PatentEP2883425B1Designs for control on solar power system with extreme low energy consumption
Publication Date: 2024.09.18 LIGHTING TAIWAN
  • EP2883425B1 patent drawingFigure 1
  • EP2883425B1 patent drawingFigure 2
  • EP2883425B1 patent drawingFigure 3

AI summary

This patent discloses designs of a controller for a solar powered LED lamp system. The control unit includes a controller that has a switching network and that selectively charges a battery from a solar panel, and selectively discharges the battery to power a lamp. The lamp itself includes a second part of the control unit that prevents over-charge and under-charge conditions of the battery. This may be accomplished using a low power passive network of LEDs and resistors, leaving the controller itself to only perform switching. Thus, the power consumed by the controller, and by the LED lamp system as a whole, may be significantly reduced.