Otto J. M. Smith (1917-2009) was an educator, inventor and author in the fields of engineering and electronics. He spent most of his career as a professor at University of California Berkeley. Dr. Smith is probably best known for the invention of the Smith predictor, a method of handling deadtime in feedback control systems:
"A somewhat more complicated solution to the deadtime problem was proposed in 1957 by Otto Smith (see 'The Smith Predictor: A Process Engineer's Crystal Ball,' Control Engineering, May 1996). Mr. Smith demonstrated how a mathematical model of the process could be used to endow the controller with prescience to generate just the right control moves without waiting to see how each move turned out. "
It was for this achievement that he was listed in InTech's "Leaders of the Pack" as one of the 50 most influential industry innovators since 1774. Other notable early achievements of Dr. Smith were the purchase in 1951 of the rights to his sine-function generator, U.S. patent 2,748,278 by Hewlett Packard, and in 1958, the publication of a technical textbook on feed back control systems by McGraw-Hill.
More recently Smith developed methods of running three-phaseinduction motors on single-phase power. He also worked on methods of providing power to single phase supply lines from three phase generators. His first patent in this field, "Three-Phase Induction Motor with Single-Phase Power Supply", U.S. patent 4,792,740, was issued 20 December 1988. He coined the words "enabler" and "phaseable" and "semi-hex" to distinguish these techniques from traditional static phase conversion, rotary phase conversion and electronic means of synthesizing three phase voltages and current. These techniques allow the use of large three phase motors up to over 100hp where only single-phase power is available. Beginning in 1976 all of his patents have been for devices to generate or conserve energy. Among his patents are designs of patents for solar generators, wind generators and high efficiency motors. That portion of the US patent database that is searchable by name (since 1975) lists 15 inventions by Smith in these fields. Smith has published over 150 papers. The list of patents in this article should be nearly complete.
Professor, Escola Federal de Engenharia de Itajubá, Itajubá, Minas Gerais, Brasil, March-Sept., 1974.
Visiting professor, Technical University Eindhoven, The Netherlands, Jan.-Feb., 1974.
NSF Appointee, U.S.-Romania Cooperative Science Program. Sept.-Dec., 1973. Academia Studii Economica and Institutui Studii si Proiectari Energetici. Optimum long-term economic planning.
Visiting Lecturer, Escola Federal de Engenharia de Itajubá, Itajubá, Minas Gerais, Brasil, and University of Chile, Santiago, Chile, 1971.
Senior Research Fellow in Economics and Engineering, Monash University, Melbourne, State of Victoria, Australia, 1966–1967.
Test Engineer, Doble Engineering Company, Medford, Massachusetts. 1941–1943.
Research Assistant, H. J. Ryan High-Voltage Laboratory, Stanford University, Stanford, California, 1938–1941.
Degrees
Ph.D. in Power and High Voltage, Stanford University, 1941.
B.S. in Electrical Engineering, University of Oklahoma, Norman, 1938.
B.S. in chemistry, Oklahoma State University, Stillwater, 1938.
Patents
U.S. patent 2,583,132 Jan. 22, 1949. “Inspection Apparatus”, X-Ray thickness gauge for steel rolling mill, jointly with William Altar.
U.S. patent 2,748,278 May 29, 1956. “Sine-Wave Generator”. (HP Model 202A ultra-low frequency 0.01Hz.
U.S. patent 3,483,463 Dec. 9, 1969. “System and Method for Alternating Current Machines, and Apparatus Therefor”. (Variable-speed, Precision frequency, originally filed Dec. 5, 1952, Pat. Application No. 324,318.).
U.S. patent 2,829,333 April 1, 1956, “Constant-Frequency Alternating-Current Generators”, by Wilfred L. Turvey, All 8 claims were awarded to Otto J. M. Smith in Interference 89,735 decision Nov. 29, 1960.
U.S. patent 2,854,617 Sept. 30, 1958. “Frequency Control Apparatus for Alternators”. Leopold J. Johnson. All interference Claims awarded to Otto J.M. Smith.
U.S. patent 2,886,766 May 12, 1959. “Frequency Stabilization System”. by Donald K. Gibson. All interference Claims awarded to Otto J. M.Smith, December 1965.
U.S. patent 3,070,740 Dec.25, 1962, “Constant Frequency Generator”, by K. M. Chirgwin et al., (9 Claims dependent upon Smith 3,483,463.)
U.S. patent 3,051,883 Aug. 28, 1962. “Dead-Beat Response, Resonant Load, Control System and Method”. (Posicast control, 30 claims.)
U.S. patent 3,060,378 Oct. 23, 1962. “Method and Apparatus for Generating a Signal and a System for Utilizing the Same”. (Complex-Zero Generator, 38 claims.)
U.S. patent 3,084,859 April 9, 1963. “Number Storage Apparatus and Method”. (Phase-shift Counter.) (28 claims.)
U.S. patent 3,141,982 July 21, 1964. “Control System for Use in Control of Loops With Dead Time”. (Dead-Time Stabilization) * 3,241,129 Mar. 15, 1966. “Delay Line”. 29 claims, jointly with Richard Dye.
U.S. patent 3,388,305 June 11, 1968. “System, Apparatus and Method for Improving the Stability of Synchronous Machines”. (Optimal Excitation Control, 101 claims.)
U.S. patent 3,526,761 Sept. 1, 1970. “Method, Apparatus and System for the Identification of the Relationship Between Two Signals”. (41 claims.)
U.S. patent 3,529,174 Sept. 15, 1970. “Power System With Transient Control and Method”. (94 claims, switched capacitors).
U.S. patent 3,662,251 May 9, 1972. “Method and System For Measuring Acceleration and Velocity”. (47 claims).
U.S. patent 3,662,252 May 9, 1972. “Tachometer and Method For Obtaining a Signal Indicative Of Alternator Shaft Speed”. (25 claims.)
3,742,391, June 26, 1973. “Method, Apparatus and System for the Identification of the Relationship Between Two Signals”. (13 claims.)
Brazil Pat. No. 7,806,173. Sept. 20, 1978, “Sistema Colector Solar”.
Brazil Pat. No. 7,806,485. Sept. 29, 1978, “Sistema De Energia Solar”.
U.S. patent 4,164,123 Aug. 14, 1979. “Solar Thermal Electric Power Plant”. (42 claims.)
U.S. patent 4,204,407 May 27, 1980. “Heated Piping System for a Fusible Salt Heat Exchange Fluid in a Solar Power Plant”.
U.S. patent 4,219,729 Aug. 26, 1980. “Method of Aligning and Locating the Mirrors of a Collector Field With Respect to a Receptor Tower”. (20 claims.)
U.S. patent 4,247,182 Jan. 27, 1981. “Heliostat With a Protective Enclosure”. (24 claims.)
U.S. patent 4,249,386 Feb.10, 1981. “Apparatus for Providing Radiative Heat Rejection From a Working Fluid Used in a Rankine Cycle Type System”. Joint with Phyllis S. Smith.
“Heliostato con una Caja Protectora”, (Heliostat With a Protective Enclosure) Mexico Certificate of Invention, August 19, 1980.
Mexico Certificate of Invention No. 5159. April 7, 1983.“Mejoras En Heliostato Con Una Caja Protectora”.
Mexico Certificate of Invention No. 101442. June 26, 1985. “Aparato para Proporcionar la Eliminacion del Calor Radiative a Partir de un Fluido Operante Que Se Usa en un Sistema del Tipe de Ciclo Rankine”, (Apparatus for Providing Radiative Heat Rejection From a Working Fluid Used in a Rankine Cycle Type System). Joint with Phyllis S. Smith.
Mexico Certificate of Invention No. 101538, June 13, 1985. “Mejoras a Sistema de Calentamiento Para Red de Tuberia Calentada por Fluido de Intercambio Termico de Sal Fusible en una Instalacion de Energia Solar”, (Heated Piping System for a Fusible Salt Heat Exchange Fluid in a Solar Power Plant.)
Egypt Pat. No. 16390, July 30, 1986. “Solar Collector System”.
Egypt Pat. No. 16391, July 30, 1986. “Solar Thermal Electric Power Plant”.
Mexico Certificate of Invention No. 101821. Sept. 5, 1986. “Um Metodo Para Alinear y Colocar los Espejos de un Campo Colector con Respecto a una Torre Receptora” (Method of Aligning and Locating the Mirrors of a Collector Field With Respect to a Receptor Tower).
U.S. patent 4,792,740 Dec. 20, 1988. “Three-Phase Induction Motor With Single Phase Power Supply”. (44 claims.)
Chinese Certificate of Patent For Invention Cert. No. 65335. Patent Application No. 95105163.6 dated April 18, 1995. Duration 20 years from Date of Filing.
U.S. patent 5,545,965 Aug. 13, 1996. “Three Phase Motor Operated From a Single-Phase Power Supply and Phase Converter”. (26 claims.)
Brazilian Pat.No. 9304033-4. Apr. 17, 2001. “Motor de Inducão Elétrica de Rotor em Forma de Gaiola”. (Three-Phase Cage-Rotor Induction Motor Control.)
U.S. patent 6,356,041 B1. Mar. 12, 2002. “Master Three-Phase Induction Motor with Satellite Three-Phase Motors Driven by a Single-Phase Supply”. (24 Claims.)
U.S. patent 7,023,167 B2. Apr. 4, 2006. “Control Arrangement for an Induction Motor Compressor Having at Least Three Windings, a Torque-Augmentation Circuit a Starting Capacitor and a Resistive Element. (7 Claims.)
Selected publications
"Posicast Control of Damped Oscillatory Systems", Proceedings of the IRE, Sept. 1957 Volume: 45, Issue: 9 page(s): 1249–1255 ISSN0096-8390
"Feedback Control Systems" McGraw-Hill Series in Control Systems Engineering. McGraw-Hill, New York, New York, first edition, 1958
"Sparse Solutions Using Hash Storage" Smith, O.J.M.; Makani, K.; Krishna, L.; IEEE Transactions on Power Apparatus and Systems, Volume PAS-91, Issue 4, July 1972 Page(s):1396–1404, Digital Object Identifier 10.1109/TPAS.1972.293271
"Power System State Estimation" Smith, O.J.M.; IEEE Transactions on Power Apparatus and Systems Volume PAS-89, Issue 3, Part-I, March 1970 Page(s):363 - 379, Digital Object Identifier 10.1109/TPAS.1970.292713
"Integration of Nonlinear Differential Systems with Wide Eigenvalue Range" Oswald, R.; Smith, O.J.M.; IEEE Transactions on Power Apparatus and Systems, Volume PAS-90, Issue 6, Nov. 1971 Page(s):2586–2589, Digital Object Identifier 10.1109/TPAS.1971.292909
"Large Low-Cost Single-Phase Semi-hex Motors" by Otto J.M. Smith, IEEE Transactions on Energy Conversion, Vol 14, No. 4, December 1999, pp 1353–1358 Digital Object Identifier 10.1109/60.815072
"High-Efficiency Single-Phase SEMIHEX Motors", by Otto J.M. Smith, Electrical Machines and Power Systems, Vol. 26, No. 6, July 1998 pp 573–584.
"High-Efficiency Single-Phase Air Conditioner", California Energy Commission Report EISG No. P500-02-003F 15 February 2002, by Otto J.M. Smith.
"High-Efficiency Three-Phase Motors Connected to Single-Phase supplies", Electrical Manufacturing and Coil Winding Conference, at The EMCW-2002 Expo. Oct. 15, 2002, Session No. 08, by Phyllis Sterling Smith and Otto J. M. Smith, Cincinnati, Ohio.
Smith, O.J.M., "Single-Phase 40HP Pump Motor", Proc.52-nd Annual Regional Conference of ASAE/CSAE, Boise, Idaho, 18-20 Sept. 1997, ASAE Paper No. 97-102, St. Joseph, Mich.: ASAE.
"High-Efficiency Air Conditione on Single Phase Electricity", California Energy Commission Preliminary Report EISG Grant #:53828A/04-08 by Otto J.M. Smith.
External links
Bibliography of Dr. Smith concerning electrical motors.
Alternating current (AC) is an electric current which periodically reverses direction and changes its magnitude continuously with time, in contrast to direct current (DC), which flows only in one direction. Alternating current is the form in which electric power is delivered to businesses and residences, and it is the form of electrical energy that consumers typically use when they plug kitchen appliances, televisions, fans and electric lamps into a wall socket. The abbreviations AC and DC are often used to mean simply alternating and direct, respectively, as when they modify current or voltage.
George Westinghouse Jr. was an American entrepreneur and engineer based in Pennsylvania who created the railway air brake and was a pioneer of the electrical industry, receiving his first patent at the age of 19. Westinghouse saw the potential of using alternating current for electric power distribution in the early 1880s and put all his resources into developing and marketing it. This put Westinghouse's business in direct competition with Thomas Edison, who marketed direct current for electric power distribution. In 1911 Westinghouse received the American Institute of Electrical Engineers's (AIEE) Edison Medal "For meritorious achievement in connection with the development of the alternating current system." He founded the Westinghouse Electric Corporation in 1886.
In electricity generation, a generator is a device that converts motion-based power or fuel-based power into electric power for use in an external circuit. Sources of mechanical energy include steam turbines, gas turbines, water turbines, internal combustion engines, wind turbines and even hand cranks. The first electromagnetic generator, the Faraday disk, was invented in 1831 by British scientist Michael Faraday. Generators provide nearly all the power for electrical grids.
A power inverter, inverter, or invertor is a power electronic device or circuitry that changes direct current (DC) to alternating current (AC). The resulting AC frequency obtained depends on the particular device employed. Inverters do the opposite of rectifiers which were originally large electromechanical devices converting AC to DC.
An induction motor or asynchronous motor is an AC electric motor in which the electric current in the rotor that produces torque is obtained by electromagnetic induction from the magnetic field of the stator winding. An induction motor therefore needs no electrical connections to the rotor. An induction motor's rotor can be either wound type or squirrel-cage type.
A rotating magnetic field is the resultant magnetic field produced by a system of coils symmetrically placed and supplied with polyphase currents. A rotating magnetic field can be produced by a poly-phase current or by a single phase current provided that, in the latter case, two field windings are supplied and are so designed that the two resulting magnetic fields generated thereby are out of phase.
A synchronous electric motor is an AC electric motor in which, at steady state, the rotation of the shaft is synchronized with the frequency of the supply current; the rotation period is exactly equal to an integer number of AC cycles. Synchronous motors use electromagnets as the stator of the motor which create a magnetic field that rotates in time with the oscillations of the current. The rotor with permanent magnets or electromagnets turns in step with the stator field at the same rate and as a result, provides the second synchronized rotating magnet field. A synchronous motor is termed doubly fed if it is supplied with independently excited multiphase AC electromagnets on both the rotor and stator.
Power engineering, also called power systems engineering, is a subfield of electrical engineering that deals with the generation, transmission, distribution, and utilization of electric power, and the electrical apparatus connected to such systems. Although much of the field is concerned with the problems of three-phase AC power – the standard for large-scale power transmission and distribution across the modern world – a significant fraction of the field is concerned with the conversion between AC and DC power and the development of specialized power systems such as those used in aircraft or for electric railway networks. Power engineering draws the majority of its theoretical base from electrical engineering and mechanical engineering.
Two-phase electrical power was an early 20th-century polyphase alternating current electric power distribution system. Two circuits were used, with voltage phases differing by one-quarter of a cycle, 90°. Usually circuits used four wires, two for each phase. Less frequently, three wires were used, with a common wire with a larger-diameter conductor. Some early two-phase generators had two complete rotor and field assemblies, with windings physically offset to provide two-phase power. The generators at Niagara Falls installed in 1895 were the largest generators in the world at that time, and were two-phase machines. Three-phase systems eventually replaced the original two-phase power systems for power transmission and utilization. Active two-phase distribution systems remain in Center City Philadelphia, where many commercial buildings are permanently wired for two-phase, and in Hartford, Connecticut.
A piezoelectric motor or piezo motor is a type of electric motor based on the change in shape of a piezoelectric material when an electric field is applied, as a consequence of the converse piezoelectric effect. An electrical circuit makes acoustic or ultrasonic vibrations in the piezoelectric material, most often lead zirconate titanate and occasionally lithium niobate or other single-crystal materials, which can produce linear or rotary motion depending on their mechanism. Examples of types of piezoelectric motors include inchworm motors, stepper and slip-stick motors as well as ultrasonic motors which can be further categorized into standing wave and travelling wave motors. Piezoelectric motors typically use a cyclic stepping motion, which allows the oscillation of the crystals to produce an arbitrarily large motion, as opposed to most other piezoelectric actuators where the range of motion is limited by the static strain that may be induced in the piezoelectric element.
This is an alphabetical list of articles pertaining specifically to electrical and electronics engineering. For a thematic list, please see List of electrical engineering topics. For a broad overview of engineering, see List of engineering topics. For biographies, see List of engineers.
A phase converter is a device that converts electric power provided as single phase to multiple phase or vice versa. The majority of phase converters are used to produce three-phase electric power from a single-phase source, thus allowing the operation of three-phase equipment at a site that only has single-phase electrical service. Phase converters are used where three-phase service is not available from the utility provider or is too costly to install. A utility provider will generally charge a higher fee for a three-phase service because of the extra equipment, including transformers, metering, and distribution wire required to complete a functional installation.
Harold Henry "Bev" Beverage was an inventor and researcher in electrical engineering. He is known for his invention and development of the wave antenna, which came to be known as the Beverage antenna. Less widely known is that Bev was a pioneer of radio engineering and his engineering research paralleled the development of radio transmission technology throughout his professional career with significant contributions not only in the field of radio frequency antennas but also radio frequency propagation and systems engineering.
An AC motor is an electric motor driven by an alternating current (AC). The AC motor commonly consists of two basic parts, an outside stator having coils supplied with alternating current to produce a rotating magnetic field, and an inside rotor attached to the output shaft producing a second rotating magnetic field. The rotor magnetic field may be produced by permanent magnets, reluctance saliency, or DC or AC electrical windings.
Doubly fed electric machines, also slip-ring generators, are electric motors or electric generators, where both the field magnet windings and armature windings are separately connected to equipment outside the machine.
Benjamin Garver Lamme was an American electrical engineer and chief engineer at Westinghouse, where he was responsible for the design of electrical power machines. Lamme created an efficient induction motor from Nikola Tesla's patents and went on to design the giant Niagara Falls generators and motors and the power plant of the Manhattan Elevated Railway in New York City.
The switched reluctance motor (SRM) is an electric motor that runs by reluctance torque and thus is a subgroup in reluctance motors. Unlike common brushed DC motor types, power is delivered to windings in the stator (case) rather than the rotor. This greatly simplifies mechanical design as power does not have to be delivered to a moving part which eliminates the need for a commutator, but it complicates the electrical design as some sort of switching system needs to be used to deliver power to the different windings. Electronic devices can precisely time the switching of currents, facilitating SRM configurations. Its main drawback is torque ripple. Controller technology that limits torque ripple at low speeds has been demonstrated. Sources disagree on whether it is a type of stepper motor.
In electrical engineering, the Korndorfer starter is a technique used for reduced voltage soft starting of induction motors. The circuit uses a three-phase autotransformer and three three-phase switches. This motor starting method has been updated and improved by Hilton Raymond Bacon.
This glossary of electrical and electronics engineering is a list of definitions of terms and concepts related specifically to electrical engineering and electronics engineering. For terms related to engineering in general, see Glossary of engineering.
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