David J. Perreault - Brookline MA Vahe Caliskan - Cambridge MA
Assignee:
Massachusetts Institute of Technology - Cambridge MA
International Classification:
H02P 910
US Classification:
322 29, 322 28, 322 36
Abstract:
An alternator system having an ac machine includes a switched-mode rectifier operating at a duty cycle selected based upon at least one of the emf, frequency or speed of operation of the ac machine. The switched-mode rectifier operates such that the alternator system provides a load match which results in output power levels which are relatively high compared with output power levels of conventional alternator systems.
David J. Perreault - Brookline MA Vahe Caliskan - Cambridge MA
Assignee:
Massachusetts Institute of Technology - Cambridge MA
International Classification:
H02M 542
US Classification:
363 89
Abstract:
A system for charging a first source from a second source includes an alternating current (ac) voltage source having an internal inductance, a switching power converter coupled to the ac voltage source and the first source, a control circuit coupled to the switching power converter, a connecting system for selectively connecting a positive terminal of the second source to the ac voltage source and a jump charging controller coupled to the control circuit and operative to enable the switching power converter to be used in conjunction with the ac voltage source inductances as a dc/dc converter to charge the first source from the second source.
David J. Perreault - Brookline MA Scott Mogren - Holliston MA
Assignee:
R. B. Carr Engineering, Onc. - Newton MA
International Classification:
A61N 200
US Classification:
600 9, 324657, 324673
Abstract:
An electromagnetic stimulator circuit has a precharge power supply, a capacitor, a set of switches, and a stimulator coil. The switches, which can be implemented using a variety of devices, enable flexible control over the coil current waveform without requiring the physical reconfiguration of circuit elements. The shape of the output current pulse is controlled by the modulation of the switches, and much of the energy applied to the coil is returned from the coil to the capacitor for reuse on the succeeding pulse. Less power is required and less heat energy is generated.
Load Matched Alternator System With Fault Protection
David J. Perreault - Brookline MA Vahe Caliskan - Chicago IL
Assignee:
Massachusetts Institute of Technology - Cambridge MA
International Classification:
H02M 542
US Classification:
363 89, 361 88
Abstract:
An alternator system having an alternating current voltage source includes a rectifier coupled to the voltage source, a sensor coupled to the voltage source and an engine and a control circuit coupled to the voltage source, the rectifier and the sensor. The control circuit provides control signals to the rectifier and the voltage source. The alternator system further includes a fault protection controller coupled to an output of the alternator system and coupled to the control circuit. The rectifier operates such that the alternator system provides a load match which results in output power levels which are relatively high compared with output power levels of conventional alternator systems and the fault protection controller operates under fault conditions (e. g. load dump), and overrides the other controllers in the alternator system based on output voltage when a load dump occurs.
Load Matched Alternator System With Fault Protection
David J. Perreault - Brookline MA, US Vahe Caliskan - Chicago IL, US
Assignee:
Massachusetts Institute of Technology - Cambridge MA
International Classification:
H02M007/217
US Classification:
363127
Abstract:
An alternator system having an alternating current voltage source includes a rectifier coupled to the voltage source, a sensor coupled to the voltage source and an engine and a control circuit coupled to the voltage source, the rectifier and the sensor. The control circuit provides control signals to the rectifier and the voltage source. The alternator system further includes a fault protection controller coupled to an output of the alternator system and coupled to the control circuit. The rectifier operates such that the alternator system provides a load match which results in output power levels which are relatively high compared with output power levels of conventional alternator systems and the fault protection controller operates under fault conditions (e. g. load dump), and overrides the other controllers in the alternator system based on output voltage when a load dump occurs.
David J. Perreault - Brookline MA, US Joshua W. Phinney - Somerville MA, US Timothy C. Neugebauer - Cambridge MA, US
Assignee:
Massachusetts Institute of Technology - Cambridge MA
International Classification:
H03H007/01
US Classification:
333177, 333172
Abstract:
An electrical component includes a capacitive impedance and a shunt path inductance cancellation feature provided by coupled windings. A filter having a capacitor with capacitor-path inductance cancellation provides enhanced performance over frequency compared with conventional capacitors.
David J. Perreault - Brookline MA, US Timothy C. Neugebauer - Cambridge MA, US Joshua W. Phinney - Glen Oaks NY, US
Assignee:
Massachusetts Institute of Technology - Cambridge MA
International Classification:
H03H 7/01 H03H 7/00
US Classification:
333177, 333172
Abstract:
An electrical component includes a capacitive impedance and a shunt path inductance cancellation feature provided by coupled windings. A filter having a capacitor with capacitor-path inductance cancellation provides enhanced performance over frequency compared with conventional capacitors.
Methods And Apparatus For Resistance Compression Networks
David J. Perreault - Brookline MA, US Juan M. Rivas - Auburndale MA, US Yehui Han - Cambridge MA, US Olivia Leitermann - Arlington MA, US
Assignee:
Massachusetts Institute of Technology - Cambridge MA
International Classification:
G05F 3/06
US Classification:
307151
Abstract:
A resistance compression network substantially decreases the variation in effective resistance seen by a tuned rf inverter as loading conditions change. Circuits can include resistance compression networks and rectifiers to form rf-to-dc converters having narrow-range resistive input characteristics.
Mark Thompson, Peter Cartmill, Michael Poitras, Kristen Goodall, Lindsay Hughes, Lauren Dunphy, Laura Sherrard, Tengteng Teng, Amalia Stenzel, Christopher Smith