Abstract: A power converter system includes first and second input terminals; a converter connected to the first and second input terminals and including an output terminal; a start-up circuit connected to a first capacitor and configured to charge the first capacitor during start-up and hiccup conditions; a voltage source connected to the first and second input terminals and configured to provide, during the start-up and hiccup conditions, a voltage proportional to a voltage applied to the first and second input terminals; and a voltage buffer including a MOSFET with a gate connected to the voltage source, a source connected to the start-up circuit, and a drain connected to one of the first and second input terminals.

Abstract: A power converter system includes first and second input terminals; a converter connected to the first and second input terminals and including an output terminal; a start-up circuit connected to a first capacitor and configured to charge the first capacitor during start-up and hiccup conditions; a voltage source connected to the first and second input terminals and configured to provide, during the start-up and hiccup conditions, a voltage proportional to a voltage applied to the first and second input terminals; and a voltage buffer including a MOSFET with a gate connected to the voltage source, a source connected to the start-up circuit, and a drain connected to one of the first and second input terminals.

Abstract: A converter includes a transformer including a primary winding and a secondary winding, a primary-side circuit connected to first and second input terminals and to the primary winding and including a switching circuit connected to the primary winding and a parallel resonant tank circuit including the primary winding and a resonant capacitor connected in parallel with the primary winding, a secondary-side circuit connected to the secondary winding and to first and second output terminals and including a rectifier circuit connected to the secondary winding, and an inductor including a primary inductor winding connected to the first input terminal and the primary winding and a secondary inductor winding connected to the secondary winding and the first output terminal.

Abstract: A start-up circuit includes a switching-device control circuit arranged to receive an input voltage and to provide a switching-device control signal, a switching device arranged to be controlled by the switching-device control signal and to provide a start-up signal, a power-converter control circuit arranged to receive the start-up signal and to provide a power-converter control signal, and a power converter arranged to receive the power-converter control signal and to provide an auxiliary output signal. The switching control circuit is arranged to receive the auxiliary output signal such that, when the auxiliary output signal reaches a predetermined level, the switching-device control circuit stops providing the switching-device control signal.

Abstract: A power conversion system includes an input terminal that is arranged to be connected to a voltage source; a transformer having a first winding connected to the input terminal and a second winding connected to an output terminal of the power conversion system, either the first winding or the second winding is provided with at least three taps that are arranged to divide the first winding or the second winding into at least two sub-windings; at least one tap switch connected to the at least two sub-windings; a control circuit connected to the at least one tap switch; and at least one switch connected to the at least one tap switch. The control circuit is arranged to control the at least one tap switch to control the turn ratio of the transformer.

Abstract: A start-up circuit includes a switching-device control circuit arranged to receive an input voltage and to provide a switching-device control signal, a switching device arranged to be controlled by the switching-device control signal and to provide a start-up signal, a power-converter control circuit arranged to receive the start-up signal and to provide a power-converter control signal, and a power converter arranged to receive the power-converter control signal and to provide an auxiliary output signal. The switching control circuit is arranged to receive the auxiliary output signal such that, when the auxiliary output signal reaches a predetermined level, the switching-device control circuit stops providing the switching-device control signal.

Abstract: A power conversion system includes an input terminal that is arranged to be connected to a voltage source; a transformer having a first winding connected to the input terminal and a second winding connected to an output terminal of the power conversion system, either the first winding or the second winding is provided with at least three taps that are arranged to divide the first winding or the second winding into at least two sub-windings; at least one tap switch connected to the at least two sub-windings; a control circuit connected to the at least one tap switch; and at least one switch connected to the at least one tap switch. The control circuit is arranged to control the at least one tap switch to control the turn ratio of the transformer.