Abstract: An apparatus for driving a light emitting device includes: a current control unit generating a current control signal according to a preset current setting value; a constant current circuit unit varying a current resistance value according to the current control signal of the current control unit, detecting a current flowing in a light emitting unit including a plurality of emitting devices by using the current resistance value, and controlling the current flowing in the light emitting unit based on the detected current; and a voltage control unit varying a voltage resistance value according to a preset voltage setting value, detecting a voltage supplied to the light emitting unit by using the voltage resistance value, and determining whether or not the voltage is in an over-voltage state, based on the detected voltage.

Abstract: The present invention provides a balance circuit including: a first balance trans having a primary coil and a secondary coil, the primary coil being connected to an output terminal of a first lamp, and the secondary coil being connected to an output terminal of a second lamp and having a current controlled by the primary coil; and a second balance trans having a primary coil and a secondary coil, the primary coil being connected to an output terminal of a third lamp, and the secondary coil being connected to an output terminal of a fourth lamp and having a current controlled by the primary coil connected to the output terminal of the third lamp, wherein the secondary coil of the first balance trans is connected to the primary coil of the second balance trans, and an inverter circuit including the same.