Frank J Nola

US Patent:

44332769, Feb 21, 1984

Filed:

Mar 14, 1983

Appl. No.:

6/476244

Inventors:

Frank J. Nola - Huntsville AL

Assignee:

The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

International Classification:

H02P 736

US Classification:

318729

Abstract:

A power control circuit for a three phase induction motor wherein power factors for the three phases are summed to provide a control signal, and this control signal is particularly filtered and then employed to control the duty cycle of each phase of input power to the motor.

US Patent:

44892438, Dec 18, 1984

Filed:

May 6, 1982

Appl. No.:

6/375684

Inventors:

Frank J. Nola - Huntsville AL

Assignee:

The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

International Classification:

H02P 780

US Classification:

307 64

Abstract:

A solar powered system wherein a load such as a compressor (16) is driven by a main induction motor (14) powered by a solar array (10), and an auxiliary motor (18) shares the load with the solar powered motor in proportion to the amount of sunlight available, is provided with a power factor controller (20) for controlling voltage applied to the auxiliary motor in accordance with the loading on that motor. In one embodiment, when sufficient power is available from the solar cell array the auxiliary motor is driven as a generator by excess power from the main motor so as to return electrical energy to the power company utility lines.

US Patent:

44006578, Aug 23, 1983

Filed:

Nov 30, 1981

Appl. No.:

6/325886

Inventors:

Frank J. Nola - Huntsville AL

Assignee:

The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

International Classification:

H02P 540

US Classification:

318798

Abstract:

A failure detector is provided for detecting unidirectional failures in triacs, particularly as used in power factor controllers for induction motors. In a first embodiment, the triac voltage waveform is sensed and upon detection of an unbalanced signal, corresponding to failure of the triac in either the positive or negative direction, the triac is turned full on in both directions. In a second embodiment, a pair of pulsed signals are derived, the pulse durations of which are proportional to the phase difference between the load current and voltage for each half cycle, and the triac is turned full on responsive to a difference in pulse duration between the half cycle signals. An unidirectional open circuit detector is adapted to use a signal from either of the first and second embodiments to turn the triac off in response to an open circuit failure in either direction.

US Patent:

44045115, Sep 13, 1983

Filed:

Oct 13, 1981

Appl. No.:

6/310714

Inventors:

Frank J. Nola - Huntsville AL

Assignee:

The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

International Classification:

H02P 126

US Classification:

318729

Abstract:

A power factor type motor controller in which the conventional power factor constant voltage command signal is replaced during a starting interval with a graduated control voltage. The present invention adds to the three-phase system of pending application Ser. No. 199,765, filed Oct. 23, 1980, means for modifying the operation of the system for a motor start-up interval of 5 to 30 seconds. The modification is that of providing via ramp generator 174 an initial ramp-like signal which replaces a constant power factor signal supplied by potentiometer 70. The ramp-like signal is applied to terminal 40 where it is summed with an operating power factor signal from phase detectors 32, 34, and 36 to thereby obtain a control signal for ultimately controlling SCR devices 12, 14, and 16 to effect a gradual turn-on of motor 10. The significant difference of the present invention over prior art is that the SCR devices are turned on at an advancing rate with time responsive to the combination signal described rather than simply a function of a ramp-like signal alone. The added signal, the operating power factor signal, enables the production of a control signal which effectively eliminates a prior problem with many motor starting circuits, which is that of accompanying motor instabilities.

US Patent:

46442340, Feb 17, 1987

Filed:

Sep 13, 1985

Appl. No.:

6/775548

Inventors:

Frank J. Nola - Huntsville AL

Assignee:

The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

International Classification:

H02P 602

US Classification:

318254

Abstract:

A control circuit is provided for a brushless three-phase d. c. motor which affords four quadrant control from a single command. The control circuit provides acceleration of the motor in both clockwise and counterclockwise directions and braking and generation in both clockwise and counterclockwise directions. In addition to turning on individual transistors of the transistor pairs connected to the phase windings of the motor for 120. degree. periods while the other transistor of that pair is off, the control circuit also provides, in a further mode of operation, turning the two transistors of each pair on and off alternately at a phase modulation frequency during such a 120. degree. period. A feedback signal is derived which is proportional to the motor current and which has a polarity consistent with the command signal, such that negative feedback results.

US Patent:

40399460, Aug 2, 1977

Filed:

Mar 18, 1976

Appl. No.:

5/667928

Inventors:

Frank J. Nola - Huntsville AL

Assignee:

The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

International Classification:

G01P 352

US Classification:

324165

Abstract:

A tachometer in which sine and cosine signals responsive to the angular position of a shaft as it rotates are each multiplied by like, sine or cosine, functions of a carrier signal, the products summed, and the resulting frequency signal converted to fixed height, fixed width pulses of a like frequency. These pulses are then integrated, and the resulting DC output is an indication of shaft speed.

US Patent:

44595280, Jul 10, 1984

Filed:

Dec 16, 1982

Appl. No.:

6/450166

Inventors:

Frank J. Nola - Huntsville AL

Assignee:

The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

International Classification:

H02P 126

US Classification:

318729

Abstract:

A phase-detector (16, 18, 20) is provided for use in a power factor controller for a three-phase induction motor. The power factor controller includes switching thyristors (10, 12 14) for each motor phase winding and the phase detector for each phase includes an operational amplifier (36) which senses the current phase angle for that phase by sensing the voltage across the phase thyristor. Common mode rejection is achieved by providing positive feedback between the input and output of the voltage sensing operational amplifier.

US Patent:

46492879, Mar 10, 1987

Filed:

Jul 31, 1984

Appl. No.:

6/636459

Inventors:

Frank J. Nola - Huntsville AL

Assignee:

The United States of America as represented by the Administrator of the
National Aeronautics and Space Administration - Washington DC

International Classification:

H02P 1318

US Classification:

307 31

Abstract:

An energy storage system for a spacecraft is provided which employs a solar powered flywheel arrangement including a motor-generator which, in different operating modes, drives the flywheel and is driven thereby. A control circuit, including a threshold comparator, senses the output of a solar energy converter, and when a threshold voltage is exceeded thereby indicating the availability of solar power for the spacecraft loads, activates a speed control loop including the motor-generator so as to accelerate the flywheel to a constant speed and thereby store mechanical energy, while also supplying energy from the solar converter to the loads. Under circumstances where solar energy is not available and thus the threshold voltage is not exceeded, the control circuit deactivates the speed control loop and activates a voltage control loop that provides for operation of the motor as a generator so that mechanical energy from the flywheel is converted into electrical energy for supply to the spacecraft loads.