A power converter-circuit (100) having a transformer (T), comprising a snubber-circuit (C.sub.sn, D.sub.Sn,S3, S.sub.3, D.sub.Sn,S4) for suppressing voltage peaks on a secondary side of the transformer (T) that comprises a snubber capacitor (C.sub.sn); and an auxiliary DC-DC converter (101) having a first input connected with the snubber capacitor (C.sub.sn) and a first output connected with a first output (V.sub.Out) of the power converter-circuit (100). This circuit increases efficiency of electrical conversion and reduces thermal losses.

An isolated switching power converter is presented. The isolated switching converter includes a transformer, a secondary-side switch and a secondary-side controller. The transformer has a primary winding coupled to an input, a first secondary winding coupled to a first output for providing a first output voltage, and a second secondary winding coupled to a second output for providing a second output voltage. The secondary-side switch is coupled to the second secondary winding. The secondary-side controller compares the second output voltage with a first reference voltage and generates a control signal based on the comparison to operate the secondary-side switch.

A method includes generating a PWM signal having a first edge to turn a transistor on and a second edge to turn the transistor off in respective switching cycles; determining a target turn on point and a target turn off point based on a measured electrical signal of the transistor responsive to the PWM signal of a switching cycle of a present control cycle; and adjusting the first edge and/or the second edge of the PWM signal for a switching cycle of a subsequent control cycle based on the determined target turn on point and/or the determined target turn off point.

Disclosed herein is an improved flyback converter that separates the magnetic components of the converter into a transformer and a separate, discrete energy storage inductor. This arrangement can improve the operating efficiency of the converter by reducing the commutation losses as compared to a conventional flyback converter. The magnetic components may be constructed on separate magnetic cores or may be constructed on magnetic cores having at least one common element, thereby allowing for at least partial magnetic flux cancellation in a portion of the core, reducing core losses.

Disclosed herein is an improved flyback converter that separates the magnetic components of the converter into a transformer and a separate, discrete energy storage inductor. This arrangement can improve the operating efficiency of the converter by reducing the commutation losses as compared to a conventional flyback converter. The magnetic components may be constructed on separate magnetic cores or may be constructed on magnetic cores having at least one common element, thereby allowing for at least partial magnetic flux cancellation in a portion of the core, reducing core losses.

A voltage converter, including an input adapted to couple to a voltage source and a transformer including a primary coil and a secondary coil. Primary side circuitry, including a first switching circuit, is coupled to the primary coil. A second switching circuit is coupled between a first terminal and a second terminal of the secondary coil, and configured to selectively close to short circuit the first terminal to the second terminal.

An apparatus includes a pulse-width modulation (PWM) generator configured to generate a PWM signal for controlling a power switch of a power converter, a bias switch and a bias capacitor connected in series and coupled to a magnetic winding of the power converter and a comparator having a first input connected to the bias capacitor, a second input connected to a predetermined reference and an output configured to generate a signal for controlling the bias switch to allow a magnetizing current from the magnetic winding to charge the bias capacitor when a voltage across the bias capacitor is less than the predetermined reference.

The present disclosure discloses a current detecting circuit of a power converter, which includes a transformer including: a magnetic core, a primary winding and a secondary winding, the primary winding and the secondary winding being coupled through the magnetic core, and a combination of the primary winding, the secondary winding and the magnetic core being used to transmit a main power of the power converter, the current detecting circuit includes: an auxiliary winding coupled to the secondary winding, the auxiliary winding and the secondary winding having the same number of turns and their dotted terminals being connected; and an impeder, one end thereof being coupled to the auxiliary winding to form a series branch, which is coupled in parallel to the secondary winding, and a terminal voltage of the impeder after being filtered being proportional to a magnitude of an output current of the power converter.

An isolated switching power converter having a primary-side and secondary-side in signal communication with an input and an output is disclosed. The isolated switching power converter comprises a transformer, primary-side switch, secondary-side switch, primary-side controller, and secondary-side controller. The transformer includes a primary-winding and a secondary-winding in signal communication with the input and output. The primary-side switch is in signal communication with the primary-winding and the secondary-side switch is in signal communication with the secondary-winding. The primary-side controller is on the primary-side and the secondary-side controller is on the secondary-side. The primary-side controller is configured to output a control signal for operating the primary-side switch and the secondary-side controller configured to monitor a voltage across the secondary-side switch, output a control signal for switching the secondary-side switch, and turn-off the secondary-side switch at an off-time of the primary-side switch to transmit a data signal to the primary-side controller.

A circuit (100) for use in voltage supply for an electrical device, having a first input (111) configured for connecting with a first voltage source, a second input (121) configured for connecting with a second voltage source, and a common output (133) configured for connecting with an input of the electrical device, comprising a first voltage converter (110) with an input connected to or being the first input (111), and configured to provide DC voltage at a first voltage level (V.sub.1) at an output (113), further comprising a second voltage converter (120) with an input connected to or being the second input (121), and configured to provide DC voltage at a second voltage level (V.sub.2) at an output (123), wherein the second voltage converter (120) is configured not to operate when a voltage level present at its output (123) is higher than a stop threshold, and to operate when a voltage level present at its output (123) is lower than a start threshold, the stop threshold is equal to or higher than the second voltage level (V.sub.2) and lower than the first voltage level (V.sub.1), and the start threshold is equal to or lower than the second voltage level (V.sub.2).