His daughter Belinda Sinclair said he passed away on Thursday morning after having cancer for more than a decade.
Sir Clive's products included the ZX series of computers and his ill-fated C5 electric vehicle.
He was still working on his inventions last week "because that was what he loved doing", said Ms Sinclair.
"He was inventive and imaginative and for him it was exciting and an adventure, it was his passion," she added.
His ZX Spectrum computers brought affordable personal computing to the masses - selling in their millions across the world.
