Greatchip Technology Co., Ltd.

Ting-Cheng Lai

Masakazu Ushijima

Wan-Lu Lin

Chien-Fu Ho

Te-Min Liu

A transformer includes primary and secondary windings coupled electromagnetically to each other and wounded respectively around primary and secondary winding portions of a bobbin unit, and a core unit mounted to the bobbin unit and including first and second core parts that form a magnetic circuit path. The first core part includes insertion and extension segments extending from a connecting segment. The second core part includes insertion and extension segments, and an adjusting segment extending from a connecting segment toward the first core part. The extension segments of the first and second core parts contact each other. The insertion segments of the first and second core parts extend respectively through the primary and secondary winding portions to contact each other.

Transformer

A current balancing circuit for first and second lamp sets includes a step-up transformer and a current balancer. The step-up transformer is adapted to be coupled to a power supply for receiving an alternating-current source power, and for generating a drive signal by varying magnitude of the alternating-current source power. The step-up transformer is further adapted to be coupled to the first and second lamp sets for providing the drive signal thereto. The current balancer includes first and second shunt transformers. Each of the first and second shunt transformers includes primary and secondary windings that correspond to each other in number of turns thereof. The first and second shunt transformers are adapted to be coupled to corresponding discharge lamps of the first lamp set. The current balancer is adapted to mirror current flowing through the first and second shunt transformers to the second lamp set.

Current balancing circuit

A lamp driving circuit includes a step-up transformer, a detector, and a controller. The step-up transformer includes a primary winding, and a secondary winding configured to cooperate with a discharge lamp to form a tank circuit that generates a tank current. The detector is adapted for detecting current magnitude of current flowing through the discharge lamp, and outputs a detecting signal corresponding to the current magnitude. The controller receives the detecting signal from the detector, and generates a drive signal for driving the step-up transformer. The controller includes a capacitor, and configures a waveform of the drive signal by controlling charging of the capacitor based on a calculation value that corresponds to a frequency of the drive signal, a start-setting value, and a difference between the detecting signal and a current-setting signal.

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Taichung, Taiwan

Ting-Cheng Lai