Patents by Inventor Martin F. Schlecht
Martin F. Schlecht has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20080151582Abstract: 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.Type: ApplicationFiled: September 10, 2007Publication date: June 26, 2008Inventor: Martin F. Schlecht
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Patent number: 7272023Abstract: 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.Type: GrantFiled: March 27, 2006Date of Patent: September 18, 2007Assignee: SynQor, Inc.Inventor: Martin F. Schlecht
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Patent number: 7272021Abstract: 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.Type: GrantFiled: April 20, 2006Date of Patent: September 18, 2007Assignee: SynQor, Inc.Inventors: Martin F. Schlecht, Richard W. Farrington
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Patent number: 7269034Abstract: 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.Type: GrantFiled: August 23, 2006Date of Patent: September 11, 2007Assignee: SynQor, Inc.Inventor: Martin F. Schlecht
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Patent number: 7119524Abstract: 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.Type: GrantFiled: August 3, 2004Date of Patent: October 10, 2006Assignee: Bank America, N.A.Inventors: Joshua H. Bretz, Abram P. Dancy, Leif E. LaWhite, Martin F. Schlecht
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Patent number: 7072190Abstract: 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.Type: GrantFiled: March 29, 2004Date of Patent: July 4, 2006Assignee: SynQor, Inc.Inventor: Martin F. Schlecht
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Patent number: 6927987Abstract: 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.Type: GrantFiled: November 13, 2002Date of Patent: August 9, 2005Assignee: SynQor, Inc.Inventors: Richard Farrington, Abram P. Dancy, Leif E. LaWhite, Martin F. Schlecht
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Patent number: 6894468Abstract: 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.Type: GrantFiled: July 7, 2000Date of Patent: May 17, 2005Assignee: Synqor, Inc.Inventors: Joshua H. Bretz, Abram P. Dancy, Leif E. LaWhite, Martin F. Schlecht
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Publication number: 20040207459Abstract: A charge pump circuit in a gate controller provides a pumped gate control voltage to switches of a DC/DC converter. Different input voltages may be applied to the controller and an input voltage higher than the charge pump output could result in circuit damage. A clamp circuit between the input and output prevents the output voltage from being significantly below the input voltage to prevent such damage. The clamp circuit may be a transistor controlled by a comparator or amplifier.Type: ApplicationFiled: January 26, 2004Publication date: October 21, 2004Applicant: SynQor, Inc.Inventors: Thomas Farkas, Abram P. Dancy, Leif E. LaWhite, Martin F. Schlecht
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Patent number: 6731520Abstract: 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.Type: GrantFiled: February 5, 2003Date of Patent: May 4, 2004Assignee: SynQor, Inc.Inventor: Martin F. Schlecht
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Patent number: 6594159Abstract: 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.Type: GrantFiled: March 29, 2001Date of Patent: July 15, 2003Assignee: SynQor, Inc.Inventor: Martin F. Schlecht
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Publication number: 20030123264Abstract: 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.Type: ApplicationFiled: November 13, 2002Publication date: July 3, 2003Applicant: SynQor, Inc.Inventors: Richard Farrington, Abram P. Dancy, Leif E. LaWhite, Martin F. Schlecht
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Publication number: 20030112645Abstract: 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.Type: ApplicationFiled: February 5, 2003Publication date: June 19, 2003Applicant: SynQor, Inc.Inventor: Martin F. Schlecht
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Publication number: 20010010637Abstract: 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.Type: ApplicationFiled: March 29, 2001Publication date: August 2, 2001Applicant: SynQor, Inc.Inventor: Martin F. Schlecht
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Patent number: 6222742Abstract: 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.Type: GrantFiled: October 13, 1999Date of Patent: April 24, 2001Assignee: SynQor, Inc.Inventor: Martin F. Schlecht
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Patent number: 5999417Abstract: 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.Type: GrantFiled: January 23, 1998Date of Patent: December 7, 1999Assignee: Fische, LLCInventor: Martin F. Schlecht
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Patent number: 5396527Abstract: A logic circuit is driven by a single alternating voltage power supply so that the energy stored in parasitic capacitances can be mostly recovered, rather than dissipated, as in conventional logic designs. Successive stages of the logic circuit are of opposite conductivity types such that the successive stages are activated in alternate half cycles of the power supply without separate clock signals. Each stage of the logic circuit is precharged during a respective first half cycle of the power supply and is active in logical processing during a second half cycle. The half cycles are defined by the rising and falling edges of the power supply. The logic circuit resonates with an inductor coupled across the power supply but closely coupled to the logic circuit. This inductor and the method of charging and discharging the capacitors in the logic circuit serve to minimize the power dissipated during logical processing.Type: GrantFiled: July 8, 1994Date of Patent: March 7, 1995Assignee: Massachusetts Institute of TechnologyInventors: Martin F. Schlecht, Roderick T. Hinman
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Patent number: 5043043Abstract: An electrostatic micromotor employs a side drive design. The stator operates in a plane above a substract and a moveable member lies and moves in the plane of the stator. An electrostatic field of operational strength is generated and sustained without breakdown in the plane between the stator and edges of the moveable member. Three fabrication processes enable formation of a moveable member in the plane of operation of the stator and spaced apart from the stator by a micron amount. One fabrication process deposits and patterns a structural layer to form the stator and moveable member over a sacrificial layer. A second fabrication process etches channels in a first structural layer to outline a stator, moveable member, and if desired, a bearing. A substrate is connected to the side of the structural layer through which the channels are etched and the opposite side is ground down to the ends of the channels to form salient stator, rotor and, if desired, bearing structures.Type: GrantFiled: June 22, 1990Date of Patent: August 27, 1991Assignee: Massachusetts Institute of TechnologyInventors: Roger T. Howe, Jeffrey H. Lang, Martin F. Schlecht, Martin A. Schmidt, Stephen D. Senturia, Mehran Mehregany, Lee S. Tavrow
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Patent number: 4997521Abstract: An electrostatically driven microactuator is micromachined in a monolithic process. Sacrificial layers are placed between a moving element and stator structural layers. Removal of the sacrificial layers leaves a free standing moving element and micron wide air gaps within a stator. An electric field of about 100 Mv/m and higher is supported across the micron wide gap without breakdown and enables high energy torque densities to be produced between the stator and the moving element. One electrostatic drive scheme involves a series of stator electrodes attached to the stator and a series of electrodes attached to the moving element charged in sequence to attract each other in a direction of movement and to oppose each other in a direction normal to movement. A bearing is aligned with the moving element within the stator during the layering of a sacrificial layer over an edge of the moving element structural layer. The bearing and stator laterally stabilize the moving element.Type: GrantFiled: April 25, 1989Date of Patent: March 5, 1991Assignee: Massachusetts Institute of TechnologyInventors: Roger T. Howe, Jeffrey H. Lang, Martin F. Schlecht, Martin A. Schmidt, Stephen D. Senturia
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Patent number: 4967243Abstract: A power semiconductor device which comprises either a bipolar transistor or a MOSFET, incorporates an integral Schottky diode in antiparallel connection with the transistor for conducting reverse current through the power semiconductor device. By fabricating the diode to exhibit a lower turn-on voltage, than the P-N junction at the base and collector interface in the bipolar transistor, or at the base and drift layer interface in the MOSFET, the power semiconductor device, when in the reverse conduction mode, exhibits excellent reverse recovery characteristics and without forward voltage overshoot transients.Type: GrantFiled: July 19, 1988Date of Patent: October 30, 1990Assignee: General Electric CompanyInventors: Bantval J. Baliga, Martin F. Schlecht