Exxon Research and Engineering Company

Massachusetts Institute of Technology

Reliance Electric Company

Spellman High Voltage Electronics Corporation

Other

Gould Inc.

Richard H Baker

S Merrill Skeist

Derek Chambers

Kevin E White

James L Kirtley, Jr

Edward L Maddox

Anthony G P Marini

Arthur A Baumgarten, Jr

Lawrence H Bannister

Bruce D Semanchik

Miroslav Glogolia

Krista K Finigan

David L Chu

An electro-mechanical energy conversion system coupled between an energy source and an energy load comprising an energy converter device including a permanent magnet induction machine coupled between the energy source and the energy load to convert the energy from the energy source and to transfer the converted energy to the energy load and an energy transfer multiplexer to control the flow of power or energy through the permanent magnetic induction machine.

Electro-mechanical energy conversion system having a permanent magnet machine with stator, resonant transfer link and energy converter controls

An electro-mechanical energy conversion system coupled between an energy source and an energy load including an energy converter device having a doubly fed induction machine coupled between the energy source and the energy load to convert the energy from the energy source and to transfer the converted energy to the energy load and an energy transfer multiplexer coupled to the energy converter device to control the flow of power or energy through the doubly fed induction machine.

Doubly fed induction machine

An energy transfer multiplexer to control the flow of power or energy between an energy source and an energy load comprising a bi-directional inverter including a first bank or plurality of switches or first plurality of energy transfer control points and a second bank or plurality of switches or second plurality of energy transfer control points operatively coupled by a series resonant transfer link to selectively control the direction of power or energy flow between the first and second bank or plurality of switches or the first and second plurality of energy transfer control points.

Energy transfer multiplexer

A variable output induction motor drive system for use with a polyphase variable output alternating current motor including a rotor and stator to drive an operating load such as an automotive vehicle, the variable output induction motor drive system comprises a sine wave current generator operatively coupled to a direct current power source to receive direct current therefrom and to generate a variable sine wave current and operatively coupled to the polyphase variable output alternating current motor to selectively feed the variable sine wave current thereto and a sine wave current control coupled between the sine wave power current generator and the polyphase variable output alternating current motor to monitor the operating parameters of the polyphase variable output alternating current motor and to control the amplitude and frequency of the variable sine wave current fed from the sine wave current generator to the polyphase variable output alternating current motor to control the output torque and speed thereof.

Variable output induction motor drive system

This invention is related generally to detachable assemblies and more particularly to novel hardware for easily attaching or removing portable members from stationary structures. A quick acting fastener assembly is described for attaching a portable member, such as a toilet seat, to a stationary member, such as a toilet bowl, for example. The portable member carries a pair of headed pins fixed to the margin thereof and projecting outward to mate with receptacles on the stationary member. Said pins and the mating receptacles are of a unique design such that when the pins are inserted into the matching receptacles the portable member is securely fastened to the stationary member, yet can be removed, disengaged, without any adjustments (levers pulled, fasteners removed, etc.). The distinguishing feature of this invention is in the simplicity of the mechanical hardware, the absence of moving parts, springs, fasteners, levers, or removable nuts, etc.

Detachable toilet seat

A solid state relay is responsive to a control signal and is used with an impedance load and a source of alternating electrical power. The solid state relay is used to connect and disconnect the load from the source of alternating electrical power. The solid state relay turns on in response to a control signal and to a substantially zero voltage crossing of the alternating electrical power of the source. The solid state relay turns off in response to the control signal and to a substantially zero current crossing of the alternating electrical power of the source.

MOSFET AC switch

A low voltage series pass regulator configuration has an input terminal for receiving a predetermined input voltage and an output terminal operatively connected to a load. The regulator comprises at least one field effect transistor in a source follower configuration. The drain of the field effect transistor is operatively connected to the input terminal and the source is operatively connected to the output terminal which provides an output voltage across the load. In one embodiment of the present invention a current limiter is operatively connected between the source and a gate of the field effect transistor. In another embodiment of the present invention a comparator for comparing the output voltage to a first reference voltage is provided. The comparator supplies a control voltage, indicative of the value of the output voltage compared to the first reference voltage, to the gate of the field effect transistor. This output voltage is indicative of the current drawn by the load and causes the comparator to produce a control voltage on the gate which keeps the output voltage substantially constant.

Field effect regulator with stable feedback loop

A DC to N phase AC converter, where N is an integer greater than 2, includes a DC source having first and second terminals for deriving equal amplitude opposite polarity DC voltages, a series resonant circuit, and N output terminals, one for each phase of the converter. The series resonant circuit is selectively connected in series with the first and second terminals and the N output terminals for an interval equal to one half cycle of the resonant circuit resonant frequency, so that current flows between a selected one of the first and second terminals and the resonant circuit and a selected one of the N output terminals during the interval. The resonant circuit current is zero at the beginning and end of the interval. A capacitor shunting each of the output terminals has a value relative to the capacitance of the series resonant circuit such that the voltage across each output terminal remains approximately constant between adjacent exchanges of energy between the resonant circuit and the output terminal. The selective connection is in response to a comparison of the actual voltage across each of the N output terminals and a reference voltage for each of the N output terminals. The comparison controls when the flow of current between the selected first and second terminals and the selected output terminal via the resonant circuit begins. The frequency of the AC voltage developed across the N output terminals is much less than the resonant frequency of the circuit.

Series resonance charge transfer regulation method and apparatus

In an inverter comprising power transistors selectively switched on and off to supply a predetermined current waveform to an inductive load, including a standard RC voltage snubber for suppressing load generated voltage surges during turn-off transitions of the switching transistors, an auxiliary snubber is connected across the load to provide snubbing at the start of the turn-off transitions when the conventional voltage snubber is inoperative due to an inherent snubber time constant. The auxiliary snubber comprises a grounded capacitor that is maintained charged directly from the voltage supply. The output of the capacitor is connected to the load through an SCR that is gated on during the on periods of the switching transistors during normal operation. The output voltage is equal to the auxiliary snubber capacitor voltage during normal operation so that there is no current flow through the SCR. During a load current overload, the switching transistors are turned off. Because the output voltage during overload is less than the auxiliary snubber capacitor voltage, the capacitor immediately discharges into the load to supply the overload current.

Auxiliary voltage snubber circuit

The d.c. power supplied by a photovoltaic solar panel to a load is controlled by monitoring the slope of the panel voltage vs. current characteristic and adjusting the current supplied by the panel to the load so that the slope is approximately unity. The slope is monitored by incrementally changing the panel load and indicating whether the resulting change in current derived from the panel is above or below a reference value, indicative of the panel voltage. In response to the change in the monitored current being above the reference value, the slope of a voltage vs. current curve is greater than unity and the load is adjusted to decrease the current supplied by the panel to the load. Conversely, in response to the current being less than the reference value, the slope of the voltage vs. current curve is less than unity and the load is adjusted to increase the current supplied by the panel to the load.

Method of and apparatus for enabling output power of solar panel to be

In one embodiment of the invention, a switching circuit is provided by connecting the main current paths of a plurality of relatively low voltage transistors in series for switching a relatively high level of voltage, with zener diodes being connected across the main current paths of each one of the transistors, the zeners having a breakdown voltage rating no greater than the inverse voltage rating of their respective transistor, and polarized for breaking down whenever the inverse voltage rating of the transistor is exceeded, the zener diodes also providing a voltage divider circuit for applying appropriate levels of bias voltage to the common connections between the transistors for ensuring the inverse voltage ratings of the transistors are not exceeded at times that the transistors are all turned off, or non-conductive.

Biasing methods and circuits for series connected transistor switches

A high-power, solid-state switching circuit includes in a preferred embodiment a first switching device susceptible to damage from excessive peak power dissipation at times of turn-on and turn-off in switching high currents from a relatively high-voltage supply, the first switching device having its main current path connected in parallel with the main current path of a second switching device that is substantially less susceptible to such damage from excessive peak power dissipation, but which has a substantially higher impedance in its main current path than the first device when turned on, the devices complementing one another via the operation of said switching circuit for turning on the second device before the first device, thereby substantially lowering the voltage across the main current path of the first device, allowing the latter to be turned on and turned off with substantially reduced peak power dissipation via the snubbing effect of the second device, and the first device relative to the second device providing substantially reduced power dissipation during the on-state of the switching circuit.

Self-snubbing bipolar/field effect (biofet) switching circuits and method

A protection circuit for a switching amplifier having a plurality of serially stacked switching transistors includes a voltage breakdown device and a current responsive device for sensing the voltage developed between the emitter and collector electrodes of each conducting switching transistor. The base drive for any transistor is removed in response to Vce of a switching transistor exceeding a predetermined value.

Protection circuit for switching transistors serially connected between

A common mode rejection coupler in a power switching system having a variable common mode voltage includes a first optical isolator circuit for receiving an input signal and generating in response thereto a first signal which is normally isolated with respect to the common mode voltage. A second optical isolator circuit receives the complement of the input signal and generates a second signal which is also normally isolated with respect to the common mode voltage. The first and second signals are the complement of one another. A comparator receives the first and second signals and generates an output signal which changes state only when the first and second signals complement states. Feedback control circuitry for the comparator is provided for limiting transient changes in one of the first and second signals to prevent the comparator from changing output states when a transient change occurs in one of the first and second signals resulting from a change in the common mode voltage.

Common mode rejection coupler

A high-current VMOS transistor having a source connected to a floating reference voltage terminal is switched between conducting and non-conducting states by a low power source including complementary-symmetry FET's. When the VMOS is back biased a low impedance path having a constant predetermined voltage exits between the VMOS source and drain via one of the bipolar transistors. This prevents false triggering of the VMOS if the reference voltage drops below a nominal value. A diode polarized to pass current oppositely from the source drain path and in shunt with the source drain path prevents the VMOS from conducting if the reference voltage rises above the nominal value. The bipolar transistors are shunted by a zener diode to maintain a predetermined voltage across the bipolar transistors, i.e. between the reference voltage terminal and a terminal connected through a load resistor to a power supply terminal.

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Bedford, MA, United States of America

Richard H Baker