Abstract: Methods, systems, and devices are described for an adjustment module that interacts with a parameter detection module to provide a threshold value for initiating switching of a switching module in a cyclical electronic system. Aspects of the present disclosure provide a switching module used in conjunction with an inductor that is coupled with the switching module. The threshold voltage for switching the switching module may be adjusted to provide switching at substantially zero volts while maintaining sufficient energy in the inductor to drive the voltage at a switching element in the switching module to zero volts. Such auto-adjustment circuits may allow for enhanced efficiency in cyclical electronic systems. The output of an up/down counter may be used to set another parameter that effects the performance of the cyclical electronic system in order to enhance the performance of the cyclical electronic system.

Abstract: A bridgeless power factor correction system may include an AC input having a first input terminal and a second input terminal, an inductor module coupled with the first input terminal, and a switching module coupled between the second input terminal and the inductor module. The switching module may comprise a bi-directional voltage blocking switch that is configured to selectively couple the inductor module with the AC input based on an output voltage and a phase difference between an input voltage waveform and an input current waveform. The switching module may also comprise an auxiliary network for reversing a winding current to achieve zero voltage switching. An output module may be coupled with the inductor module, and provide an output to a load. The inductor module may include a magnetically coupled inductor having a primary and secondary winding. The output module may include a full or half bridge rectifier.

Abstract: Methods, systems, and devices are described for an adjustment module that interacts with a parameter detection module to provide a threshold value for initiating switching of a switching module in a cyclical electronic system. Aspects of the present disclosure provide a switching module used in conjunction with an inductor that is coupled with the switching module. The threshold voltage for switching the switching module may be adjusted to provide switching at substantially zero volts while maintaining sufficient energy in the inductor to drive the voltage at a switching element in the switching module to zero volts. Such auto-adjustment circuits may allow for enhanced efficiency in cyclical electronic systems. The output of an up/down counter may be used to set another parameter that effects the performance of the cyclical electronic system in order to enhance the performance of the cyclical electronic system.

Abstract: Methods, systems, and devices are described for a non-isolated dc-dc power converter that uses a single magnetic element and provides both a positive and a negative voltage output. The magnetic element, such as an inductor, is coupled with two or more switching modules that electrically switch the inductor to and from a voltage source, an inductor terminal, and/or a load. By electrically connecting and electrically isolating different components at various times, separate positive and negative voltage outputs are provided using the single inductor element. Switching may be controlled by a controller module, and a magnitude of the dc output voltage may be selected based on two or more resistors coupled with the controller module.

Abstract: Methods, systems, and devices are described for using isolated and non-isolated circuit structures and control methods for achieving multiple independently regulated input and output parameters using a single, simple, primary magnetic circuit element. For example, structures and methods are revealed for achieving single-stage power factor correction with high power factor and multiple independently regulated outputs using a single, simple, primary magnetic circuit element. Other structures and methods are revealed for achieving multiple independently regulated outputs without power factor correction using a single primary magnetic circuit element for both isolated and non-isolated power conversion applications.

Abstract: Methods, systems, and devices are described for using coupled inductor boost circuits to operate in a zero current switching (ZCS) and/or a zero voltage switching (ZVS) boundary mode. Some embodiments include a coupled inductor boost circuit that can substantially eliminate rectifier reverse recovery effects without using a high side primary switch and a high side primary switch driver. Other embodiments include a coupled inductor boost circuit that can achieve substantially zero voltage switching. ZCS and ZVS modes may be effectuated using control techniques. For example, a magnetizing current may be sensed or otherwise represented, and a signal may be generated accordingly for controlling switching of the controller.

Abstract: Synchronous rectifier self drive mechanisms are revealed which are universally applicable to zero voltage switching power converters which rely on an auxiliary inductor to drive the critical turn on transition of the main switch of the power converter. The voltage wave form generated by the auxiliary inductor is well suited to synchronous rectifier self drive. Voltage limiting circuits that reduce the voltage swing of synchronous rectifier gates are also revealed. These voltage limiting circuits reduce the energy circulated into and out of the synchronous rectifier gates and protect the synchronous rectifier gate circuits from negative over voltage.

Abstract: Simple adaptive gate drive circuits, applicable to switches that turn on at zero voltage, such as mosfets or IGBTs, are revealed. The new gate drive circuits improve the timing for turn on of the switches, reduce gate drive losses, and limit gate voltage stress. In its simplest form the gate drive circuit requires only a single small mosfet and two diodes. The adaptive gate drive circuit provides optimal switch turn on timing for the case in which the drive energy available to drive the turn on transition is sufficient to drive the main switch to zero volts. The adaptive gate drive circuit also provides optimal switch turn on timing for the case in which the energy available to drive the transition is insufficient to drive the transition all the way to zero volts, turning the main switch on at the minimum main switch voltage thereby minimizing main switch switching losses.

Abstract: A highly efficient and simple power conversion circuit (300) having zero voltage switching (ZVS) includes a novel switch timing technique, such that the need for an leakage inductor connected in series with the primary circuit of the converter and rectifier diodes is eliminated. A switch timing circuit (351) located in an output side circuit (350) enables the use of the natural stored magnetic energy in the output side circuit (350) to drive the critical switching transitions to accomplish soft switching for all of the switches (314-317) in a full bridge forward converter (300) for all transitions. This power conversion circuit (300) includes a full bridge circuit (310) having plurality of switching devices (314-317) that intermittently couple the primary winding (327) to the input of the power converter (300). A transformer (326) couples to receive power from the full bridge circuit (310) into its primary winding (327).

Abstract: Five circuit synthesis methods, for forming new power conversion circuits with enhanced electromagnetic compatibility and improved AC performance from old circuits with AC performance and/or electromagnetic compatibility deficiencies, are revealed. The new synthesis methods achieve performance improvements without requiring the addition of magnetic cores. In all cases a simple toroidal magnetic core structure is not precluded. In all cases splitting or adding magnetic windings is required, and, in many cases, additional capacitors are required. Many new circuits formed by applying the synthesis methods are revealed. The results achieved by application of the synthesis methods include zero ripple current at all terminals without adding magnetic cores or requiring a complex magnetic circuit element, cancellation of common mode currents, improved control loop bandwidth, and faster transient response.

Abstract: Composite switches comprising multiple mosfets arranged in cascode which achieve higher efficiency and faster switching are revealed. The gate of a lower mosfet, a low voltage small die size mosfet, is driven with a conventional control circuit for modulation of the composite switch. The upper mosfet, a large die size high voltage mosfet, is controlled at its source terminal by the smaller mosfet while the gate of the upper mosfet is connected to a capacitor whose voltage remains fixed such that no net drive power is required by the gate circuit to drive the upper mosfet. The composite switch simultaneously achieves the low conduction losses of a large die device with the gate drive losses and fast switching of a small die device.

Abstract: The power converter of this invention accomplishes zero voltage switching at both turn on and turn off transitions of a primary switch (206). A transformer (218) serves as both energy storage device and isolation mechanism. Inductance (216) placed in series with transformer (218) provides energy to drive the turn on resonant switching transition of switch (206). Additional energy storage is provided by a required primary side filter capacitor (220) and an output filter capacitor (224). During a first operational state in which switch (206) conducts, energy is transferred from power source (202) to transformer (218) and capacitor (220). During the first state, capacitor (224) supports a load (226). During a second operational state, a second primary switch (212) and a secondary switch (234) conduct and energy is transferred from capacitor (220) and transformer (218) to series inductance (216), capacitor (224) and load (226).