The single-spiral filament enhances lighting efficiency through the following mechanisms:
- Thermal Energy Concentration
The design of a single-spiral filament helps concentrate heat energy.
Its helical structure reduces the contact area between the filament and the surrounding environment, thereby minimizing heat dissipation and retaining more heat within the filament.
As a result, a greater proportion of electrical energy is converted into light rather than lost as heat, effectively improving luminous efficiency.
- Increased Filament Length and Resistance
The spiral configuration allows for a longer filament to be placed within a limited bulb space while using a smaller wire diameter, thereby increasing its electrical resistance.
According to Ohm’s law, the resistance of a conductor depends on its length and cross-sectional area — increasing length and reducing diameter raise the resistance, which in turn reduces current under a given voltage.
This lowers thermal loss and improves energy utilization, thus enhancing lighting efficiency.
- Expanded Emitting Area and Higher Brightness
The helical design enables the filament to be more evenly distributed inside the bulb, increasing the overall light-emitting area.
A larger emitting area allows more light to radiate outward, improving overall brightness.
Meanwhile, the longer filament length means more tungsten atoms participate in the incandescence process, further enhancing luminous output.
- Improved Structural Elasticity
The spiral shape also gives the filament mechanical elasticity, allowing it to absorb and relieve the stress caused by thermal expansion during heating.
This flexibility reduces the risk of deformation or breakage, maintaining long-term stability and consistent lighting performance.
- Reduced Internal Light Absorption
During design optimization, the orientation of the spiral turns is carefully adjusted to minimize self-shadowing and internal light absorption.
By refining the filament’s geometric parameters — such as pitch, coil diameter, and wire spacing — engineers can reduce these losses, ensuring that more emitted light escapes efficiently from the bulb.
Conclusion
In summary, the single-spiral filament improves lighting efficiency through thermal energy concentration, increased filament length and resistance, expanded emitting area, enhanced elasticity, and reduced internal light absorption.
These engineering optimizations enable the single-spiral filament to deliver higher brightness, greater stability, and improved energy conversion efficiency — making it a highly effective design for modern lighting applications.