S A INSTITUTE OF ELECTRICAL ENGINEERS
Trade in Sandton

Ionospheric recorder Wadley receiver Wire recorder Current balance Crystal set Marconiphone Lightning recorder The first integrated circuit? Lightning impulses induced in an external antenna caused the coherer to conduct and operate the telegraph relay situated on the right hand side of the instrument. The relay activated the armature of the central assembly having a striker that de-cohered the coherer. The instrument is part of the South African Institute of Electrical Engineers historical collection and can be viewed in Observatory, Johannesburg, South Africa. He named it the Audion and it was subsequently known as the triode vacuum tube (valve). ELECTRICAL POWER FREQUENCY CONTROL Electrical power suppliers were legally required to maintain mains frequency within close limits. The accurate pendulum clock was kept in step with standard South African time by regular corrections. The clock is part of the South African Institute of Electrical Engineers historical collection and can be viewed in Observatory, Johannesburg, South Africa. This instrument revolutionised land surveying as it became possible to measure distance as quickly and accurately as measuring angles. In 1896 primitive equipment was already in use in South Africa. By the end of the Anglo-Boer war there were probably as many as 20 X-ray units in operation. This tube is typical of early units that depended on a rather poor vacuum of about 10 mPa to produce cathode rays (electrons). The power station was established to supply electrical power to the gold mines in the Sabie district of Mpumalanga (or Eastern Transvaal as it was then known.) James Gordon & Company Limited of London manufactured the three turbines in The turbine is on loan to Gold Reef City, Johannesburg. This grid supplied air to the Central District Gold mines. The resistance, to be measured, is then inserted between the terminals on the right, with the crank set on the button, corresponding to the sensitiveness, and with the key in the middle depressed. The ohmmeter is now part of the South African Institute of Electrical Engineers historical collection and can be viewed in Observatory, Johannesburg, South Africa. The instrument was used to measure low resistance up to 1,8 ohms. The Tinsley Phase Splitting Resistance consists of a variable number of non-inductively wound resistance coils. The instrument is now part of the South African Institute of Electrical Engineers historical collection and can be viewed in Observatory, Johannesburg, South Africa.s. A PHASE ANGLE METER manufactured in the USA by Weston Electrical Instrument Corporation, Newark, New Jersey. The instrument measures the angle between the current and the voltage in an AC circuit when these quantities are represented by vectors. A FLAME-PROOF MINE TELEPHONE manufactured by Siemens Brothers and Company Limited, London.