A Low-Cost Linear LED Driver for Light Bulb Based on Harmonic Standard

摘要

Since lighting system is used in every hμman activity,an electronic device with more power efficient and low cost,rather than electrical equipment,has been developed.HPLED(High Power Light Emitting Diode)has been applied in many aspects to replace the conventional lighting.A significant part of the system is LED Driver,which is important to improve efficiency,adjusted voltage and current output.Some problems may occur and cause harmonic distortion.There are two types of drivers commonly developed such as Linear Driver and Switching Driver.Linear driver is a circuit easier to implement and to find error compared to switching driver.A linear LED driver circuit must fit the Harmonic Standard requirements.In this study,some comparisons and measurements due to IEEE 519-1992 and IEC 61000-3-2 standards were conducted to evaluate the power quality.The results showed that the measurement of Linear Driver using LM 317 and IN4733 in accordance to the Harmonic Standard were PF 0.92,THDi 37.5%,THDv 1.9% for LM317 Driver and PF 0.86,THDi 25.4% and THDv 2.1% for IN4733A,respectively.