Led street lamp design question and answer ( Eight) Series-parallel of LED street lamp power supply and power

Circular traffic lights q: LED street lamp of series-parallel and how to design the PFC power factor: a: LED street lamp power PFC ( Power factor correction) , there are three: one is not to bring a PFC without a dedicated circuit power factor compensation, the PF value at zero. About 65; 2 it is passive power factor

ring lights to ask: how to design the series-parallel led street lamp and power factor correction; A: led street lamp power supply power factor correction has three types: one is without power factor compensation of power factor correction special circuit, the power factor is about 0. 65; Secondly, the passive power factor correction circuit power factor compensation with the best reliability and wide application, power factor is in commonly 0. Around 92. Finally, the active power factor compensation circuit is called the APFC circuit. If you choose 1 w = 1. 5 uf, PF value can reach 0. 99, but the cost is the second of two times, lower reliability. Therefore, the second kind of plan to use more, according to the design series of led street lamp power supply quantity is no more than 45 string bead. However, in order to obtain the power factor of relatively large, the number of lamp bead series cannot be too small, otherwise cannot achieve the best working state. Isolated power supply series on the number of associated with the number of turns of the secondary winding.