Emergency Lighting Device With Galvanic Isolation And Independent Current Regulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing emergency lighting devices lack electrical isolation between circuit parts during mains operation, and current regulation is not independently controlled from the light output, leading to inefficiencies and safety concerns.
Innovation Solution
An emergency lighting device with a clocked second converter, such as a flyback converter, powered exclusively by an energy store, and a control circuit that regulates discharge current independently of the light output, ensuring galvanic isolation and efficient power management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If parts of the emergency lighting device are connected to mains voltage during normal operation, then the light source can be supplied in mains operation, but electrical isolation between circuit parts is lost and safety risks increase
Solution Approach 1:
The patent divides the emergency lighting device into separate isolated circuit sections: a mains voltage input circuit, a charging circuit with first isolation element, a second converter with second isolation element, and a light source circuit. This segmentation ensures that each circuit part operates at its own potential level, maintaining electrical isolation even when the light source is powered during mains operation, thus resolving the contradiction between power supply capability and electrical isolation safety.
2Device complexity
If the current supplied to the illuminant is not regulated, then the circuit is simpler, but energy efficiency decreases and the energy store cannot be optimized
Solution Approach 1:
The patent implements a control circuit that monitors the state of the energy store and regulates the discharge current accordingly. The control circuit adjusts the duty cycle of the second converter based on feedback from the energy store status, ensuring optimal current regulation during emergency operation. This feedback mechanism enables efficient energy management without excessively complicating the overall circuit design, balancing simplicity with energy efficiency.
Solution Approach 2:
The patent employs a clocked second converter (flyback converter) that can be supplied exclusively by the energy store, with the control circuit driving the switch to regulate discharge current or discharge power independently of light output. By changing the operating parameters of the converter (switching frequency, duty cycle), the system achieves efficient current regulation while maintaining relatively simple circuit architecture.
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 provides electrical isolation and independent current regulation, enabling efficient power supply to the light source during both mains and emergency operations, with high efficiency and flexibility in voltage adjustment, achieving over 80% energy storage efficiency.
Implementation Method 1
a clocked second converter with at least one switch, preferably a flyback converter
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to an emergency lighting device for controlling a lighting means, comprising an energy store, such as a battery or an accumulator, a charging circuit for the energy store having connections for an AC voltage (alternating voltage), wherein the charging circuit has a potential isolation element, a potentially isolated clocked converter supplied from the energy store and having a switch, preferably a flyback converter, wherein the converter preferably can be supplied only by the energy store, a control circuit for controlling the switch, and a supply path from the secondary side of the converter to connections for the lighting means.