There is a close relationship between the length of the tungsten wire and the power of the bulb. When the rated voltage is constant, the power of the bulb is mainly determined by the resistance of the filament, and the resistance of the filament is related to its length, thickness and material. The following is a detailed analysis of this relationship:
- The relationship between resistance and power
According to the calculation formula of electric power P=U²/R (where P represents power, U represents voltage, and R represents resistance), when the voltage U is constant, the smaller the resistance R, the greater the power P. Therefore, the power of the bulb is inversely proportional to the resistance of the filament.
- Relationship between resistance and tungsten wire length
Resistance R is proportional to the length L of the metal wire (here tungsten wire) and inversely proportional to the cross-sectional area S. The formula is R=ρL/S, where ρ is the resistivity, L is the length, and S is the cross-sectional area. When the material and cross-sectional area of the tungsten wire are constant, the longer the tungsten wire, the greater the resistance.
- Relationship between tungsten wire length and bulb power
Combining the above two points, we can conclude that when the rated voltage is constant, the longer the tungsten wire, the greater the resistance, and the smaller the power of the bulb; conversely, the shorter the tungsten wire, the smaller the resistance, and the greater the power of the bulb. Therefore, the length of the tungsten wire is one of the important factors affecting the power of the bulb.
- Considerations in practical applications
In practical applications, in order to obtain bulbs of different powers, manufacturers will adjust the length and/or thickness of the tungsten wire. For example, for occasions requiring high-power lighting, manufacturers may use shorter tungsten wires or thicker tungsten wires to reduce resistance, thereby increasing power; while for occasions requiring low-power lighting, longer tungsten wires or thinner tungsten wires may be used to increase resistance, thereby reducing power.
More details of tungsten wires, please visit website: http://tungsten.com.cn/tungsten-wires.html
Please contact CHINATUNGSTEN for inquiry and order of tungsten needles:
Email: sales@chinatungsten.com
Tel.: +86 592 5129595
