6.1 – Introduction

Introduction

The practical benefit of active devices is their amplifying ability. Whether the device in question be voltage-controlled or current-controlled, the amount of power required of the controlling signal is typically far less than the amount of power available in the controlled current. In other words, an active device doesn’t just allow electricity to control electricity; it allows a small amount of electricity to control a large amount of electricity.

Because of this disparity between controlling and controlled powers, active devices may be employed to govern a large amount of power (controlled) by the application of a small amount of power (controlling). This behavior is known as amplification. An amplifier (or amp) is an electronic device that is found on biomedical (and other) equipment where it is used to increase the power of a signal (voltage or current).

Operational Amplifiers, also known as Op-amps, are basically a voltage amplifying device designed to be used with components like capacitors and resistors, between its in/out terminals. They are essentially a core part of analog devices. Feedback components like these are used to determine the operation of the amplifier. The amplifier can perform many different operations (resistive, capacitive, or both), giving it the name Operational Amplifier.

Chapter 6 will discuss the different classifications of amplifiers and their arrangements. In addition, we will gain an understanding of how amps and op-amps function.