Lutron

Lutron's story begins with the engineer Joel Spira. In the 1950s, while working on an aerospace industry project, he realised that the project's thyristors could also vary the brightness of a lamp. Spira left his job to refine the idea, tested prototypes in his New York apartment and filed the patent on 15 July 1959. The result was a solid-state dimmer small enough to fit in an ordinary wall box, unlike the large rheostats used in theatres.

Joel and his wife, Ruth Rodale Spira, founded Lutron in 1961. The company started in a bedroom of the couple's Manhattan apartment and later moved to Coopersburg, Pennsylvania, where its headquarters remain today. The first residential dimmer was the Capri, advertised as a way to set the mood in a room. Spira led the company for 54 years, held more than 300 US patents and was a member of the US National Academy of Engineering. Lutron remains privately held.

Over time, Lutron went far beyond the dimmer. Its catalogue now includes keypads, whole-home lighting systems, motorised shades and blinds and, after acquiring Ketra of Austin, Texas, fixtures that adjust the colour and temperature of light. According to the National Academy of Engineering, it offers around 14,000 products, sold in more than a hundred countries. In 2010, items from the company's first 50 years, such as Spira's first engineering notebook, were donated to the Smithsonian.