Charles W.R. Campbell, electrical engineer, was the son of Reverend Alexander H. Campbell and his wife Emily. He received his education at St Leonard's College, St Andrews, Scotland, and Malvern College, in Great Malvern, Worcestershire. After completing an apprenticeship with the civil and mechanical engineering firm Thornewill & Warham, in Burton-on-Trent, he obtained experience in the design, manufacture and installation of mining machinery with various firms in England. He obtained further professional experience on the European continent, particularly in France. While still in England he married Edith L. Richards, with whom he had two sons.
Campbell came to South Africa in 1895 and was employed on the engineering staff of various firms on the Witwatersrand. Among others he was chief electrical engineer to the Johannesburg Consilidated Investment Company. In January 1907 he joined the Victoria Falls and Transvaal Power Company and was appointed as its distribution superintedent in 1909, a post he held until his retirement. In this position he was responsible for the construction, operation and maintenance of the company's electrical transmission and distribution system. Among others he designed the first wireless telephone system in South Africa, used between the company's Brakpan and Witbank power stations. He was also largely responsible for the design and installation of the country's first broadcasting equipment, under the auspices of the Associated Scientific and Technical Societies of South Africa.
In December 1909 Campbell was elected as the first president of the South African Institute of Electrical Engineers, for the year 1909/10. His presidential address, delivered at the first ordinary meeting of the institute in January 1910, was entitled "Mutual dependence of engineers of various branches" and was published in the Transactions (1910, Vol. 1(1), pp. 8-15). During the next two decades he contributed several other papers to the institute's Transactions: "Troubles on overhead power lines" (1910), "The design and installation of transformers from an operating point of view" (1911/12), "Some effects of explosives on overhead line structures" (1922), "Electrolytic rectification" (1924), and "Wired wireless. Application to a 132 kV transmission line" (1926, 1927). He was elected as the first honorary life member of the institute in recognition of his services.
By 1906 Campbell was a member of the South African Association for the Advancement of Science, but his membership had lapsed by 1910. In addition to his professional expertise he had a specialised knowledge of photography and was a pioneer in the techniques of colour photography and cinematography. In 1915 he and Frank G.A. Roberts of Johannesburg applied for a United States patent (granted in 1922) for a system to superimpose component images to form colour pictures, particularly moving pictures.