Two important parameters of led fluorescent lamps that must be known
1. Power factor (PF): Power factor is the cosine value of the phase difference between voltage and current. Because both current and voltage are wave graphs, one is a sine graph and the other is a cosine graph; because the two waveform graphs differ by 1/4 period (ie: 90 degrees), the PF value is formed. In order to increase the PF value, it is necessary A correction circuit is added to the power supply, so the cost of a power supply with a high PF value is relatively high. The PF value without a PF correction circuit is generally around 0.6, and the PF value with a PF circuit can basically reach around 0.9 or even higher.
When the PF value is low, it will pollute the power grid of the entire power supply system. When the PF value is low, the utilization rate of power generation by the electrical equipment on the grid becomes lower. Therefore, the country has a PF value requirement for some high-power electrical equipment. For those below 50W, there is no clear requirement. The national requirement is that the PF value is greater than 0.6.
2. Conversion efficiency: Generally speaking, it is the ratio of output power to input power. For example, 10W of electric power is consumed by a lamp tube, but only 8W of electric power is used to emit light (also known as useful work). If the 2W electric power is lost due to heat on the power supply device (also known as: useless work), then the power conversion efficiency of this lamp is 80%.
