Rhymebus Corporation

Lsc Ecosystem Corporation

Chang-Ming Wang

Ming-Shi Huang

Kuan-Cheng Chen

Ming-Chang Chou

Hsiao-Wu Wang

A switching circuit includes a power switch, an active clamping circuit, and an active clamping control unit. When the power switch is modulated between an ON state and an OFF with a predetermined frequency, the active clamping control unit is configured to activate the function of the active clamping circuit for absorbing the energy of voltage surges. When the power switch is operating in the ON state or the OFF state, the active clamping control unit is configured to deactivate the function of the active clamping circuit for preventing the counter EMF from damaging the power switch.

Switching circuit with controllable active clamp function

AC motor driving system and driving method thereof are provided. The driving system and method are capable of increasing power factor, adjusting waveform of the DC ripple voltage for increasing driving efficiency. The driving system is basically constructed by connecting three circuits. The first circuit is a three-phase full wave rectifying circuit and is used to transfer commercial electricity to a first DC voltage. Then, the second circuit is used to transfer the first DC voltage to a second DC voltage that ripples voltage thereof having a semi-sinusoidal waveform. The third circuit is an AC driving circuit, and receives the second AC voltage for driving the AC motor. Thereby, the driving efficiency can be increased. The capacitance used in the present disclosure has low capacitance value, thus the power factor can be increased, and usage time of the AC motor driving apparatus can also be increased.

Growing community of inventors

Taipei, Taiwan

Chang-Ming Wang