Control & Automation

#TBT: Smithsonian Celebrates Lighting: How the Dimmer Was Invented

Lutron founder Joel Spira donates the 1958 journal that started it all -- plus a c. 1959 picture of a make-shift lab in Spira's apartment bedroom in this week's edition of Throwback Thursday.

The Capri was the first dimmer commercialized by Lutron in the early ‘60s.

Photos & Slideshow

Julie Jacobson · April 9, 2015

In this edition of Throwback Thursday, CE Pro goes back to May of 2010 to remember Lutron founder Joel Spira, who passed away this week.

Last week, the Smithsonian Institution’s National Museum of American History celebrated the dimmer as part of a permanent exhibition on lighting.

Naturally, then, the inventor of the solid-state dimmer, Lutron founder Joel Spira, would be celebrated as well.

During a press event and subsequent gala that attracted government officials, loyal customers, family and friends, Spira formally signed over the following artifacts to the Smithsonian (click here for photos):

  • Oldest Capri dimmer in the Lutron archives (circa 1964), first solid-state dimmer
  • Capri marketing display from the 1960s
  • Capri advertisement from the 1960s
  • Joe Spira’s first journal, “Notebook A”
  • Nova dimmer (1971), first linear slide dimmer
  • RanaX (1989), first IR dimmer and remote control
  • NeTwork (1990), first whole-house lighting control system
  • GRAFIK Eye (1993), first customizable dimming system for different light sources
  • RadioRA system (1997), first two-way RF whole-house lighting control system
  • Vierti(2007), single-touch dimmer
  • Skylark eco-dim dimmer (2008) that limits light output to 85%
  • Serena (1993) motorized window shading system

A Dimmer is Born

So just how did Spira invent the dimmer?

A number of years ago, someone showed him a solid-state device called a silicon controlled rectifier (SCR), which is about the size of a large pea. The SCR worked by chopping out a varying portion of the 60-cycle sine wave.

During World War II in the Navy, Spira had a device for secret radars that did the same thing as the SCR, but was much larger – about the size of a milk carton.

Struck by the device’s ability to control electrical power, he figured he could put it in a wallbox and dim an ordinary light bulb.

While it wasn’t the first dimming device, it was the only one smaller than a breadbox and thus the only one that could fit inside a standard wallbox.

Spira received a patent on the dimmer in 1962.

Check out photos of interesting artifacts and anecdotes from the Smithsonian affair.

How Lutron Landed in the Smithsonian
Videos: Lutron’s Joel Spira Talks Lighting Successes, Failures
Lutron Chairman’s Wife Confirms Lighting’s Impact on Romance

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  About the Author

Julie Jacobson is founding editor of CE Pro, the leading media brand for the home-technology channel. She has covered the smart-home industry since 1994, long before there was much of an Internet, let alone an Internet of things. Currently she studies, speaks, writes and rabble-rouses in the areas of home automation, security, networked A/V, wellness-related technology, biophilic design, and the business of home technology. Julie majored in Economics at the University of Michigan, spent a year abroad at Cambridge University, and earned an MBA from the University of Texas at Austin. She is a recipient of the annual CTA TechHome Leadership Award, and a CEDIA Fellows honoree. A washed-up Ultimate Frisbee player, Julie currently resides in San Antonio, Texas and sometimes St. Paul, Minn. Follow on Twitter: @juliejacobson Email Julie at

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  Article Topics

Control & Automation · Lighting · News · Media · Slideshow · Dimmers · Joel Spira · Lighting Control · Lutron · Smithsonian · TBT · All Topics
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