Research on reliability tolerance design technique for the constant-current power supply of LEDs used on street lamp

The stability and consistency of the output current of the constant-current power supply (CCPS) of light emitting diodes (LEDs) used on street lamps directly affect the reliability of the lighting system. The components' parameters of the CCPS are influenced by internal and external disturbance factors, which cause the fluctuations of current output. This paper firstly introduces an improved method of reliability tolerance design. This method adopts a series of mathematical approaches in the procedure of tolerance design, such as orthogonal experiment, uniform experiment and regression analysis. Then, the model of constant-current power supply of LEDs used on street lamps is established and simulated using Orcad/Pspice and the method of reliability tolerance design is applied on the constant-current power supply of LEDs. Finally, the stability and consistency of the output current are ensured. This method can significantly alleviate the workload of tolerance design.