Entrepreneur and inventor.

Sinclair has been an iconic and often controversial figure in British industry for over 25 years. Fascinated by electronics from an early age, he started his own company, Sinclair Radionics Ltd., in 1961. Their most successful products were a miniature television set and the world's first electronic pocket calculator.

In 1975, after a poorly designed digital watch proved a commercial failure, Sinclair set up another company, Science of Cambridge. Their MK14, a tiny home computer launched in 1978, was a great success.

In 1980 he founded Sinclair Computers (later renamed Sinclair Research). They produced the ZX80, the world's smallest and cheapest home computer at the time. This was followed by the ZX81 and the ZX Spectrum. Both designs were phenomenally successful.

Then Sinclair lost his Midas touch. In 1985 he introduced a new concept in personal transport - the three-wheeled, electric Sinclair C5 vehicle. Widely condemned as unsafe and impractical, it was a financial disaster. Sinclair was forced to sell his microcomputer division and brand to Amstrad.

Sinclair, who was Chairman of Mensa from 1980 until 1997, was awarded a knighthood in 1983. He continues to produce a variety of innovative products from his London headquarters.