Joel Solon Spira (March 1, 1927 – April 8, 2015) was an American inventor,

entrepreneur Entrepreneurship is the creation or extraction of economic value. With this definition, entrepreneurship is viewed as change, generally entailing risk beyond what is normally encountered in starting a business, which may include other values t ...

, and business magnate. He invented a version of the light- dimmer

switch In electrical engineering, a switch is an electrical component that can disconnect or connect the conducting path in an electrical circuit, interrupting the electric current or diverting it from one conductor to another. The most common type of ...

for use in homes around the United States and led his Lutron Electronics Company into the production of lighting controllers.

Early life and education

Spira was born in

New York City New York, often called New York City or NYC, is the most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the most densely populated major city in the Un ...

in 1927 to a Jewish family. He received a

Bachelor of Science A Bachelor of Science (BS, BSc, SB, or ScB; from the Latin ') is a bachelor's degree awarded for programs that generally last three to five years. The first university to admit a student to the degree of Bachelor of Science was the University o ...

degree in physics from

Purdue University Purdue University is a public land-grant research university in West Lafayette, Indiana, and the flagship campus of the Purdue University system. The university was founded in 1869 after Lafayette businessman John Purdue donated land and mone ...

West Lafayette, Indiana West Lafayette () is a city in Wabash Township, Tippecanoe County, Indiana, United States, about northwest of the state capital of Indianapolis and southeast of Chicago. West Lafayette is directly across the Wabash River from its sister cit ...

, in 1948 and became a benefactor with his wife, including the School of Mechanical Engineering Ruth and Joel Spira Award and others.

Career

In the 1950s, he worked for an aerospace company, where he was assigned to develop a reliable trigger for

atomic weapons A nuclear weapon is an explosive device that derives its destructive force from nuclear reactions, either fission (fission bomb) or a combination of fission and fusion reactions ( thermonuclear bomb), producing a nuclear explosion. Both bom ...

. Suggested by others at the laboratory, he called on the

thyristor A thyristor () is a solid-state semiconductor device with four layers of alternating P- and N-type materials used for high-power applications. It acts exclusively as a bistable switch (or a latch), conducting when the gate receives a current ...

, a solid state

semiconductor A semiconductor is a material which has an electrical conductivity value falling between that of a conductor, such as copper, and an insulator, such as glass. Its resistivity falls as its temperature rises; metals behave in the opposite way. ...

switch. During his research, he recognized that the device could also be employed to vary the intensity of light. A lighting dimmer existed at the time, but was expensive, complicated, and necessitated the use of large

rheostat A potentiometer is a three-terminal resistor with a sliding or rotating contact that forms an adjustable voltage divider. If only two terminals are used, one end and the wiper, it acts as a variable resistor or rheostat. The measuring instrume ...

s, about 10 in (25 cm) in size. Though there were dimming devices already in use for theater lighting, they were far too big and bulky for use in homes. Spira successfully manipulated a

, a solid-state semiconductor small enough to fit into the wall box that housed a standard

light switch In electrical wiring, a light switch is a switch most commonly used to operate electric lights, permanently connected equipment, or electrical outlets. Portable lamps such as table lamps may have a light switch mounted on the socket, base, or i ...

. Unlike theatrical dimmers, Spira's standalone device was small enough for home application. He resigned from his job at the

aerospace Aerospace is a term used to collectively refer to the atmosphere and outer space. Aerospace activity is very diverse, with a multitude of commercial, industrial and military applications. Aerospace engineering consists of aeronautics and astr ...

laboratory to concentrate on refining the device. Spira then went on to conduct experiments on a ping-pong table in his Riverside Drive apartment in New York City, which led to a device capable of dimming the lighting in a home or office setting.

Lutron Electronics Company

Spira became—as a result of his discovery—best known for his initial, seminal invention: the first successful solid state-electronic dimmer. He filed for a patent on July 15, 1959 (U.S. 3,032,688). On the basis of the dimmer alone, he and his wife Ruth Rodale Spira, who was an active associate, founded the Lutron Electronics Company in

Coopersburg, Pennsylvania Coopersburg is a borough in Lehigh County, Pennsylvania. The population of Coopersburg was 2,447 as of the 2020 census. It is a suburb of Allentown and is located miles southeast of Allentown, north of Philadelphia, and west of New York City ...

, in 1961. The privately held firm, whose headquarters remain there today, has grown into an international manufacturer and distributor not only of dimmers, but also of motorized and automated window-covering systems, as well as lighting fixtures and temperature controls. Spira headed the firm for 54 years and more recently became chair of the board and research director. He died in 2015 at the age of 88 from a heart attack in Springfield Township, Pennsylvania. He was awarded the

ASME Leonardo Da Vinci Award The American Society of Mechanical Engineers Design and Engineering Division awards yearly the Leonardo Da Vinci Award to eminent engineers whose design or invention is recognized as an important advance in machine design. The award is named after ...

in 2000 by the American Society of Mechanical Engineers Lutron has been designing and manufacturing home automation products since 1954. Lutron solutions are installed in more than 20,000 homes and businesses worldwide and are backed by a nationwide team of more than 1,000 support associates. Lutron’s expertise in th
Lutron home automation
ref> industry dates back to the invention of the first programmable dimmer in 1954.

References

{{DEFAULTSORT:Spira, Joel S. 1927 births 2015 deaths American inventors Businesspeople from Pennsylvania Businesspeople in electronics