A driving apparatus includes a voltage transforming unit and a detector. The driving apparatus is used for supplying a drive voltage to a load. The voltage transforming unit is used for transforming a direct current (DC) voltage to the drive voltage. The detector is connected to the load for detecting a forward voltage across the load to generate a detecting voltage; wherein the detector compares the detecting voltage with a first reference voltage. If the detecting voltage is smaller than the first reference voltage, the detector generates a first feedback signal; the voltage transforming unit increases the drive voltage according to the first feedback signal, the detecting voltage is defined by subtraction of the forward voltage from the drive voltage.