High-Pressure Sodium Lamp Lighting Device Acoustic Resonance Control
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Solution Overview
Problem
High-pressure sodium lamps experience a decrease in illuminance and shortened lifespan due to the acoustic resonance phenomenon, which occurs when arc discharge is disturbed by resonance frequencies in the arc tube, especially with the increasing adoption of electronic ballasts that integrate with lighting equipment.
Innovation Solution
A high-pressure sodium lamp lighting device with an arc length between 142.8 mm and 167 mm, using an electronic ballast that supplies high-frequency AC voltage, with a lighting frequency that avoids the first and second acoustic resonance frequency bands determined by specific equations based on the arc tube inner diameter, ensuring the frequency exceeds the maximum value of the second resonance band, thereby reducing the occurrence of acoustic resonance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If high frequency AC voltage is supplied to high-pressure sodium lamp with electronic ballast, then lighting efficiency is improved, but acoustic resonance phenomenon occurs causing illuminance decrease and shortened lamp life
Solution Approach 1:
The patent applies parameter changes by carefully selecting and controlling the operating frequency of the electronic ballast to avoid acoustic resonance bands. By adjusting the frequency parameter away from resonant values, the harmful resonance phenomenon is eliminated while maintaining the efficiency benefits of high-frequency operation. This is achieved by designing the electronic ballast to operate at frequencies that do not coincide with the natural acoustic resonance frequencies of the arc tube.
2Use of energy by moving object
If high frequency AC voltage is supplied to high-pressure sodium lamp with electronic ballast, then lighting efficiency is improved, but acoustic resonance phenomenon occurs causing illuminance decrease
Solution Approach 1:
The patent resolves this contradiction by changing the frequency parameter of the electronic ballast to operate outside the acoustic resonance bands. By selecting operating frequencies that avoid resonance, the arc discharge remains stable and illuminance is maintained at high levels while still benefiting from the energy efficiency of high-frequency operation.
3Ease of manufacture
If arc tube inner diameter is increased, then manufacturing ease is improved, but acoustic resonance frequency bands shift to lower frequencies affecting operation
Solution Approach 1:
The patent addresses this by establishing a relationship between arc tube inner diameter and operating frequency. When arc tube dimensions are changed for manufacturing reasons, the operating frequency of the electronic ballast is adjusted accordingly to avoid the shifted resonance bands. This ensures that regardless of the arc tube size, the system operates in a stable, non-resonant condition.
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 occurrence of acoustic resonance, leading to improved illuminance and extended lamp life by selecting appropriate arc tube dimensions and electronic ballast characteristics that avoid resonance frequencies, thus stabilizing the arc discharge.
Implementation Method 1
a high-pressure sodium lamp of arc length AL within the scope of 142.8 mm≤AL≤167 mm; and electronic ballast configured to supply a high frequency AC voltage to the high-pressure sodium lamp
Implementation Method 2
an acoustic resonance phenomenon occurs in an arc tube when a high-pressure metal vapor discharge lamp including the high-pressure sodium lamp is lit with high frequency
Data Source
AI summary
The present technology provides a high-pressure sodium lamp lighting device that reduces occurrence of the acoustic resonance phenomenon. A high-pressure sodium lamp lighting device of one aspect of the present invention comprises a high-pressure sodium lamp of arc length AL within the scope of 142.8 mm≤AL≤167 mm. The lighting device also includes an electronic ballast configured to supply a high frequency AC voltage to the high-pressure sodium lamp. A lighting frequency of the electronic ballast is a frequency that avoids a first and a second acoustic resonance occurrence bands f1 kHz and f2 kHz determined based on equations from an arc tube inner diameter D mm of the high-pressure sodium lamp. The equation for f1 is a range of f1min to f1max=(−7.4D+130) to (−8.3D+156). The equation for f2 is a range of f2 min to f2max=(−11.5D+200) to (−10.0D+197).