This disclosure describes a non-dissipative snubber circuit configured to boost a voltage applied to a load after the load's impedance rises rapidly. The voltage boost can thereby cause more rapid current ramping after a decrease in power delivery to the load which results from the load impedance rise. In particular, the snubber can comprise a combination of a capacitive element, two inductive elements, and three switches, where a duty cycle of two of the three switches controls the voltage boost. The snubber can be arranged between a DC power supply and a switching circuit configured to generate a pulsed waveform for provision to the load.

An Active Clamp Flyback (ACF) converter includes a transformer module, a clamping module, and a controller. The controller is configured to: after the transformer module starts secondary side discharging, control the clamping module to start receiving leakage inductance power from the transformer module; and after controlling the clamping module to stop receiving the leakage inductance power from the transformer module, control the clamping module to release the leakage inductance power to the transformer module. The leakage inductance power released by the clamping module to the transformer module is used by the transformer module to restore a soft switching state based on the leakage inductance power. In a process of transferring the leakage inductance power to a clamping capacitor, the clamping module is in an enabled state. This reduces a loss caused by the clamping module to the leakage inductance power, and helps reduce overall loss caused by the ACF converter.

A primary controller configured for use in a power converter comprising a control circuit configured to determine a mode of operation of the power converter in response to a drive signal of a power switch. The control circuit further configured to generate a control signal in response to a signal representative of the mode of operation of the power converter, wherein the control signal represents a delay time to enable a turn on of the power switch after a turn off of a clamp switch. The control circuit further configured to generate a clamp drive signal to control the clamp switch. The primary controller further comprises a drive circuit configured to generate a drive signal to enable the power switch to transfer energy from an input of the power converter to an output of the power converter.

The power conversion device includes a converter including a main switch element, a main rectifying element, an output capacitor, and a primary winding of a coupled inductor and a resonance assist circuit based on a closed-loop circuit including a first series circuit having a secondary winding of the coupled inductor, a first rectifying element, and an auxiliary switch element, a second series circuit having a tertiary winding of the coupled inductor and a second rectifying element, and an auxiliary capacitor to which the first series circuit and the second series circuit are connected. The secondary winding and the tertiary winding are separate bodies and the first series circuit and the second series circuit are connected in parallel to the auxiliary capacitor, or the tertiary winding is integrated with the secondary winding.

Power converting devices (100) for power tools. One embodiment provides a power converter device (100) including a power source (200), a power converter (210) coupled to the power source (200), and an electronic processor (220) coupled to the power converter (210) to control the operation of the power converter (210). The power converter (210) is configured to receive an input power in one form or at a first voltage from the power source and convert the input power to an output power in another form or at a second voltage. The power converter (210) includes at least one wide bandgap field effect transistor controlled by the electronic processor (220) to convert the input power to output power.

A power supply comprises a power converter having a transformer, a low side switch configured to draw current from a supply voltage through a primary winding of the transformer and a high side switch configured to couple the primary winding of the transformer to a snubber capacitor. A controller is configured to control the power converter by generating drive signals that control the opening and closing of the high side switch and the low side switch. The controller is configured to selectively control the high side switch according to various modes of operation depending on operating conditions such as input voltage and load power consumption. The modes of operation can include, for example, a mode in which the high side switch is closed and then opened once during each of the series of switching cycles and a mode of operation in which the high side switch is closed and then opened two times during each of the series of switching cycles.

A spike suppression circuit includes a wide bandgap transistor, a first transistor, a clamping circuit, and a capacitor. The wide bandgap transistor is depletion-type. The first transistor is coupled in series with the wide bandgap transistor. The clamping circuit provides a voltage difference, and is coupled to a common node between the wide bandgap transistor and the first transistor. The capacitor provides a supply voltage for the clamping circuit. When the first transistor is turned off, the capacitor can recycle spike energy at the common node.

The subject invention reveals new methods and structures for achieving single stage power conversion with both regulated input current and regulated output voltage processing a minimum of load power and thereby achieving higher efficiency than other singles stage power converters with both regulated input current and regulated output voltage and two stage power factor corrected power converters. The subject invention reveals power factor corrected converters that improve the efficiency of the single stage power factor corrected converters on which they are based by adding an auxiliary converter that processes a small fraction of the total load power.

This disclosure describes systems, methods, and apparatus for reducing ripple in a pulsed waveform power generation system, often for use providing power to a plasma processing chamber. A snubber can be provided between a DC power supply and a switching circuit. A buck converter can also be provided between the snubber and the switching circuit, where the buck converter takes its input from within the snubber and in particular from between a rectifying and capacitive component of the snubber. In this way, the buck converter can be isolated from the DC power supply via an input inductor on a high-input line from the DC power supply.

The subject application provides a zero-voltage switching flyback converter comprising: a transformer having a primary winding and a secondary winding; a primary switch and a secondary switch for conducting the currents flowing in the primary winding and secondary winding respectively. A timing control method for operating the flyback converter are provided to accomplish zero-voltage switch by turning on the secondary switch twice within one switching power cycle.