Patent ID: 8169157

Claim:
A passive current balance driving apparatus, comprising: a first driver, comprising: a first balance capacitor having a first terminal coupled to a first terminal of an AC signal source and a second terminal providing a first balance AC-voltage; and a first rectification unit, coupled to the second terminal of the first balance capacitor, for receiving and rectifying the first balance AC-voltage so as to output a first DC-voltage to drive a plurality of first light-emitting-diodes (LEDs) connected in series; and a second driver, comprising: a second balance capacitor having a first terminal coupled to the first terminal of the AC signal source and a second terminal providing a second balance AC-voltage; and a second rectification unit, coupled to the second terminal of the second balance capacitor, for receiving and rectifying the second balance AC-voltage so as to output a second DC-voltage to drive a plurality of second LEDs connected in series, wherein a capacitive reactance of the first balance capacitor is greater than a total equivalent internal resistance of all of the first LEDs; a capacitive reactance of the second balance capacitor is greater than a total equivalent internal resistance of all of the second LEDs; and the capacitive reactances of the first and the second balance capacitors are equal.