Synqor, Inc.

Massachusetts Institute of Technology

General Electric Company

Bank America, N.a.

Fische, LLC

Martin F Schlecht

Leif E LaWhite

Abram P Dancy

Richard W Farrington

Roger T Howe

Martin Arnold Schmidt

Jeffrey Hastings Lang

Stephen D Senturia

Lennart Pitzele

Joshua H Bretz

Rene Hemond

Bantval J Baliga

David M Otten

Roderick T Hinman

Mehran Mehregany

John G Kassakian

Lee S Tavrow

Eric B Shen

Eric Bertrand Shen

Anthony J Caloggero

Bruce Rhodes

Neil Rasmussen

Leo F Casey

A power converter nearly losslessly delivers energy and recovers energy from capacitors associated with controlled rectifiers in a secondary winding circuit, each controlled rectifier having a parallel uncontrolled rectifier. First and second primary switches in series with first and second primary windings, respectively, are turned on for a fixed duty cycle, each for approximately one half of the switching cycle. Switched transition times are short relative to the on-state and off-state times of the controlled rectifiers. The control inputs to the controlled rectifiers are cross-coupled from opposite secondary transformer windings.

High efficiency power converter

Electronics mounted on a printed circuit board are housed within a high conductivity case with connecting pins extending therethrough. The case is filled with thermally conductive potting material to provide thermal conduction from the printed circuit board to the case. The case may be a conduit having open ends through which the printed circuit board is inserted or it may comprise a cover mounted to a base plate.

Method for mechanical packaging of electronics

A dc-dc converter system comprises a quasi-regulated bus converter and plural regulation stages that regulate the output of the bus converter. The bus converter has at least one controlled rectifier with a parallel uncontrolled rectifier. A control circuit controls the controlled rectifier to cause a normally non-regulated mode of operation through a portion of an operating range of source voltage and a regulated output during another portion. The bus converter may be an isolation stage having primary and secondary transformer winding circuits. For the non-regulated output, each primary winding has a voltage waveform with a fixed duty cycle. The fixed duty cycle causes substantially uninterrupted flow of power during non-regulated operation. Inductors at the bus converter input and in a filter at the output of the bus converter may saturate during non-regulated operation.

Intermediate bus architecture with a quasi-regulated bus converter

In a power converter, the duty cycle of a primary winding circuit causes near continuous flow of power through the primary and secondary winding circuits during normal operation. By providing no regulation during normal operation, a very efficient circuit is obtained with a synchronous rectifier in the secondary operating at all times. However, during certain conditions such as start up or a short-circuit, the duty cycle of the primary may be reduced to cause freewheeling periods. A normally non-regulating isolation stage may be followed by plural non-isolating regulation stages. To simplify the gate drive, the synchronous rectifiers may be allowed to turn off for a portion of the cycle when the duty cycle is reduced. A filter inductance of the secondary winding circuit is sufficient to minimize ripple during normal operation, but allows large ripple when the duty cycle is reduced. By accepting large ripple during other than normal operation, a smaller filter inductance can be used.

Power converter with isolated and regulated stages

A DC to DC power converter includes synchronous rectifiers which respond to a control waveform. Negative current from a load into the power converter is prevented by increasing the converter output voltage at a minimum current limit. The synchronous rectifiers may be held off in response to decision logic by activation of a hold-off circuit connected to a control terminal of a synchronous rectifier or of an ORing transistor at the converter output. When the synchronous rectifier is subsequently enabled, its control waveform may be increased slowly relative to the switching cycle.

Control of DC/DC converters having synchronous rectifiers

Half-bridge isolation stage topologies are provided in power converters, dividing an input voltage between capacitors. Primary transformer windings are periodically switched across respective capacitors. In current-fed implementations, the current flow through the primary windings is constrained as by an inductive element. In some implementations, a capacitor, primary winding and switch are connected in series in different orders in each of plural legs across the input. Current feed circuitry includes a current constraining component connecting nodes within each of respective legs. The switches of the isolation stage may be turned on with a fixed duty cycle, and a secondary circuit may comprise synchronous rectifiers.

Half-bridge isolation stage topologies

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Lexington, MA, United States of America

Martin F Schlecht