Analysis and Design of High Efficiency LED Driver with Variable Load

The article is based on 6.78 MegaHertz (MHz) wireless power transfer (WPT) for the design of the Light Emitting Diode (LED) driver. The constant current of variable load is realized through impedance compression network. The efficiency of the system is improved by designing the parallel capacitor $C_{\mathrm{r}}$. The 46. 8W experimental platform was built to verify that constant current can be achieved when the number of LEDs changes. LED load resistance jump from 46.8 $\Omega$ to 39.6 $\Omega$ can achieve stable constant current, and the System peak efficiency reaches 93.67%.