Career
He was the founding chairman of the Electricity Supply Commission (ESCOM, later to become Eskom) in 1923. In 1927, he was the president of the South African Institute of Electrical Engineers (South African Institute Of Electrical Engineers). Doctor van der Bijl established the Iron and Steel Corporation of South Africa (ISCOR), and was its chairman for many years.
The city of Vanderbijlpark, where ISCOR"s major steel works was built and still operates, is named after him.
He was chancellor of the University of Pretoria from 1934 until 1948. He was elected a Fellow of the Royal Society in 1944.
He is now perhaps best remembered for the van der Bijl equation which describes the relationship of the three "constants" of a vacuum tube, the transconductance gm, the gain μ and the plate resistance rp or ra. The van der Bijl equation defines their relationship as follows:.