60w Smooth Body LED Street Light
It is well known that lightning in the air emits a broad spectrum of radio waves, while overhead road lighting power lines are well accepted for wireless. The radio waves emitted by the same lightning received by the two power lines belong to the common mode interference signal for the driving circuit. The common mode interference can reach several volts to several thousand volts, which easily breaks through the driving circuit. The EMC grounding capacitor or the small clearance to the ground (to the outer casing) causes damage to the drive circuit.
To solve this problem, it is necessary to connect the fast-responding varistor to the input terminal of the LED driving circuit to ensure the leakage of differential mode interference. Since the inductive interference of lightning is repeated many times, when the interference voltage is high, the current of the varistor transient conduction bleed may be large, so the varistor should not only have a fast response capability, but also have a transient guide. The venting capacity of ten amps is not damaged. In addition to the use of varistor, the input of the LED driver circuit should also be combined with conducted interference (EMI) protection, designed with a composite LC network, so that these LC networks can not only hinder internal EMI leakage to the grid, but also The interference signal of lightning has a significant inhibitory effect.
In addition, the electrical clearance of the LED drive circuit should be kept above 7mm. The grounding capacitance of EMI protection and the insulation strength of the drive circuit should meet the requirements of reinforced insulation (4V+2750V). The drive circuit has good resistance to differential mode and common mode lightning induction.