Linear LED Lamp Shock Current Sensing and Shutdown
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Solution Overview
Problem
Linear LED lamps with internal drivers face electric shock and internal arcing hazards during relamping or maintenance, particularly when used with electronic ballasts, which can lead to consumer safety issues and fires.
Innovation Solution
A linear LED lamp design incorporating a current sensing device within the LED driving circuit and an operation monitoring module that detects electric shock currents and automatically shuts off power to prevent through-lamp electric shock, using a Buck control circuit and switches to manage current flow safely.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If a linear LED lamp with internal driver is used to replace fluorescent tube, then energy efficiency and lifetime are improved, but electric shock hazard and internal arcing risk increase during relamping or maintenance
Solution Approach 1:
The patent applies preliminary action by implementing a shock prevention switch that automatically opens before maintenance personnel can contact live electrical components. The switch is positioned to be actuated by removal of the lamp fixture itself, preemptively disconnecting power before any shock hazard can materialize during relamping operations.
Solution Approach 2:
The shock prevention switch serves as an intermediary device between the power source and the electrical components. It mediates the electrical connection by introducing a controllable break in the circuit that can be activated during fixture removal, thereby preventing direct contact between personnel and hazardous voltage without requiring personnel to manually operate electrical switches.
2Use of energy by moving object
If electronic ballast is used to operate fluorescent tube, then lighting control and efficiency are improved, but internal arcing and fire hazard increase when used with LED lamp
Solution Approach 1:
The shock prevention switch implements preliminary anti-action by preventing the conditions necessary for internal arcing before they can occur. By opening the circuit during fixture removal, it eliminates the voltage potential that would drive arcing between electrical contacts, thereby preventing the harmful effect before the ballast can generate it.
Solution Approach 2:
The invention converts the potential harm of electrical arcing into benefit by using the same mechanical action (fixture removal) that previously caused the problem as the trigger for the protective mechanism. The removal action that once exposed personnel to shock hazards now reliably actuates the switch to prevent both shock and arcing hazards.
3Object-affected harmful factors
If shock prevention switch is added to LED lamp, then electric shock risk is reduced, but device complexity increases
Solution Approach 1:
The shock prevention switch is merged with the existing lamp fixture structure rather than being a separate component. The switch utilizes the mechanical motion of fixture removal itself to actuate the electrical connection, combining the relamping operation with the shock prevention function into a single integrated mechanism.
Solution Approach 2:
The shock prevention switch serves multiple functions: it prevents electric shock during relamping, prevents internal arcing between contacts, and works with both traditional ballast-based systems and modern LED drivers. This multi-functionality justifies the added complexity by addressing multiple safety and operational requirements with a single component.
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 the risk of electric shock hazards and internal fires, ensuring safer operation and maintenance by controlling electric current flow and preventing arcing, thus enhancing user safety and product reliability.
Implementation Method 1
The LED driving circuit comprises a current sensing device that is originally used to precisely control an electric current to flow into the LED arrays. The operation monitoring module uses the same current sensing device in a way that it detects an electric shock current
Implementation Method 2
at least one rectifier; an LED driving circuit
Data Source
AI summary
A linear light-emitting diode (LED)-based solid-state lamp comprises an LED driving circuit, LED arrays, at least one rectifier, and an operation monitoring module. The LED driving circuit comprises a current sensing device that is originally used to precisely control an electric current to flow into the LED arrays. The operation monitoring module uses the same current sensing device in a way that it detects an electric shock current and determines if the linear LED-based solid-state lamp is operated in a normal mode or in an electric shock hazard mode. When an electric shock hazard is identified, the operation monitoring module shut off a return current flow from the LED arrays to reach the at least one rectifier, thus eliminating an overall through-lamp electric shock current. The scheme can effectively reduce a risk of electric shock hazard to users during relamping or maintenance.