Ron Harris (footballer) Ron Harris (footballer) Ronald Edward Harris (born 13 November 1944 in Hackney, London, England), known by the nickname "Chopper", is a former English footballer who played for Chelsea in the 1960s and 1970s. Harris is widely regarded as one of the toughest defenders of his era – along with players such as Tommy Smith and Norman Hunter – hence the nickname. His brother Allan Harris was also a professional footballer and they were teammates at Chelsea in the mid-1960s. Harris was a member of the Chelsea side which won the FA Youth Cup in 1961 and made his senior club
Optical chopper asked questions on optical choppers. Optical chopper An optical chopper is a device which periodically interrupts a light beam. Three types are available: variable frequency rotating disc choppers, fixed frequency tuning fork choppers, and optical shutters. A rotating disc chopper was famously used in 1849 by Hippolyte Fizeau in the first non-astronomical measurement of the speed of light. Optical choppers, usually rotating disc mechanical shutters, are widely used in science labs in combination with lock-in amplifiers. The chopper is used to modulate the intensity of a light beam, and a lock-in amplifier is used to improve the signal-to-noise ratio. To