| Title |
A Study on the Modularization of LED Driver for Illumination Using a Fly-Back Converter |
| Authors |
Jin-Bong Choi ; Kwan-Woo Kim ; Young-Gook Jung ; Young-Cheol Lim |
| Keywords |
LED; Fly-back converter; Multi-channel LED driver; Modularization; Burst dimming; Analogue dimming |
| Abstract |
In this paper, an improved drive method of piezoelectric PZT stack actuator for micro-positioning system is proposed and the performances are evaluated. This type of amplifier is based on switching technology efficiently handling the arbitrary regenerative energy from the piezoelectric actuator. The conventional voltage-feedback control method has the THD of ?32dB (?2.5%) with 100mHz sinusoidal reference, which means that the positioning performance in linearity degrades due to the hysteretic relationship between actuator voltage and the displacement. This paper proposed an improved charge-controlling method, which utilizes differential information of charge reference instead of integrating the actuator’s current. The current waveform has THD under -40dBV (=1%) and the displacement waveform nearly ?52dB (?0.25%), which means that the positioning performance is very excellent. Finally, another method of the displacement feedback control has better performance than the voltage method, however there exists a limitation in performance of the system. |