John Crawshaw Taylor is a prolific inventor who specialises in designing and manufacturing thermostatic controls. His ingenious integrated control system is found in in one billion electric kettles worldwide, enabling kettles to switch off automatically when the water boils, stopping the element from boiling dry and preventing plastic kettles from catching fire under a worst case scenario. 600 million of his safety controls for the small electric motors have been sold to date, and are used mainly to prevent the motor in windscreens wipers from overheating. He talks to Jim Al-Khalili about his struggle with severe dyslexia at school, the art of inventing and why he doesn't believe in selling an idea.