Computer Control of Multiple Loads

This paper reviews briefly some history of the control of voltage, current and power in alternating current circuits as applied to industrial equipment and processes. The technique of phase angle firing of thyristors (SCR´s) is shown and some non-linearities are discussed. The evolution of digital techniques and their entry into the analog world of industrial processes is reviewed. A specific controller is described in some detail and shown to be accurate, versatile and robust. Finally it is sbown that an auxillary computer can be used to control multiple outputs by time sharing basic command functions.