Factors Influencing the Design of a Solid State Analog Control System

A new analog control line was recently introduced by Hagan Chemicals & Controls, Inc. This process control line, known as the PowrMag line, was the result of about ten years of electronic development. Many factors influenced its design but the paramount considerations were 1) reliability, 2) flexibility, and 3) simplicity. Rapid advancement in improved core materials and winding techniques provided magnetic operational amplifiers of more than adequate performance. This magnetic circuitry potted in steel provided the utmost in reliability. Flexibility of design came only after the limitations of earlier equipment lines were studied in detail. The flexibility of the operational amplifier was time proven. It was, therefore, adopted for this new line. Plug-in passive elements, toper pin interconnections, and the use of a system patchboard were unique features adopted. Simplicity was achieved by the adoption of the universally-accepted operational amplifier approach. This, coupled with the black box form of the magnetic operational amplifier, provided for easy instrument technician training. These were only a few of the many factors which influenced the design of this new equipment line.