LED Emergency Lighting Brownout Detection Circuit
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional emergency lighting units rely on heavy and bulky Valve Regulated Lead Acid (VRLA) batteries and 60 Hz transformer-based chargers due to the low efficacy of incandescent lamps, which are costly and inefficient, while recent advances in LED technology offer higher luminous efficacy but at a higher initial cost, necessitating a design that reduces battery size and energy consumption without increasing costs.
Innovation Solution
An LED-based emergency lighting system utilizing a low voltage microprocessor-based circuit with AC-DC switch mode power conversion, NiMH batteries, and high power white LEDs, incorporating pulse charging algorithms and brownout detection technology to reduce battery size and maintenance power consumption, while integrating a microcontroller for charger control and monitoring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If incandescent lamps are used to provide sufficient illumination, then the required light output is achieved, but the battery size and weight increase significantly
Solution Approach 1:
The patent changes the key parameter from incandescent lamp technology to LED technology, which fundamentally alters the energy efficiency characteristics. LEDs provide the same illumination intensity with significantly lower power consumption, thereby reducing battery capacity requirements and overall system weight
2Duration of action of moving object
If VRLA batteries are used to power incandescent lamps for 90 minutes, then code-mandated run times are achieved, but the unit becomes bulky and heavy
Solution Approach 1:
The patent transitions from a 6V VRLA battery system to a 3.6V Li-ion battery system, changing the voltage and chemistry parameters. Combined with LED efficiency improvements, this allows achieving the same 90-minute run time with a significantly smaller and lighter battery package
3Use of energy by moving object
If LED light sources are used to reduce power consumption, then energy efficiency improves, but the initial cost increases
Solution Approach 1:
The patent changes the battery chemistry from VRLA to Li-ion, which has different cost characteristics. While LEDs increase light efficiency, the Li-ion battery choice balances the overall system cost while achieving superior energy efficiency and reduced size compared to traditional VRLA+incandescent systems
4Duration of action of moving object
If larger batteries are used to extend run time, then duration improves, but the charger size and weight increase
Solution Approach 1:
The patent changes from charging large 6V VRLA batteries to charging smaller 3.6V Li-ion batteries. This fundamental parameter change in battery chemistry and voltage allows for a proportionally smaller charger with reduced weight and size, while maintaining the required 90-minute emergency run time
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 system achieves a 40% increase in coverage area with 85% less battery capacity, enabling cost savings, reduced unit size, and extended battery life, along with lower maintenance requirements and energy efficiency, making LED-based solutions more viable and cost-effective.
Implementation Method 1
AC-DC switch mode power conversion technology
Implementation Method 2
rechargeable NiMH battery
Implementation Method 3
emergency lighting lamps that use high power white LEDs as the emergency lighting source
Data Source
AI summary
A brown-out detection apparatus including a voltage sensing circuit, a first circuit, and a second circuit. The voltage sensing circuit senses an input AC voltage having a first nominal input voltage value or a second nominal input voltage value. The voltage sensing circuit includes an output outputting a reference DC voltage proportional said input AC voltage. The first circuit is responsive to said output of said voltage sensing circuit. The first circuit includes a first output outputting a first voltage value when said input AC voltage is below a threshold voltage level and a second voltage value when said input AC voltage is above said threshold level. The second circuit is responsive to said first output. The second circuit includes a second output outputting a second control signal indicative of a brown-out condition of said input AC voltage.