Voltage amplification in many contr

Voltage amplification in many control systems is obtained by use of a versatile electronic circuit known as an operational amplifier. The term operational amplifier was originated by those in the analog computer field to designate an amplifier circuit that performs various mathematical operations such as summation, integration and differentiation. The circuit incorporates an electronic amplifier with passive circuit operation in such a way that circuit operation is almost entirely determined by the passive elements. Operational amplifiers are still used in electronic analog computers. However, the application of these devices has been widely extended, and they are now used in many instrumentation and control applications including signal conditioning, filtering and impedance transformation Solid-state operational amplifiers have almost entirely superseded amplifiers employing electron tubes. In addition to their inherent advantages in size, weight, power requirements, heat dissipation and reliability, solid-state amplifier have surpassed tube amplifiers in performance specifications and, in many ways, permit greater nlexibility in system design.