PARAG FERDUS

AC Waveform and AC Circuit Theory The AC Waveform Direct Current  or  D.C.  as it is more commonly called, is a form of current or voltage that flows around an electrical circuit in one direction only, making it a “Uni-directional” supply. Generally, both DC currents and voltages are produced by power supplies, batteries, dynamos, and solar cells to name a few. A DC voltage or current has a fixed magnitude (amplitude) and a definite direction associated with it. For example,  +12V  represents 12 volts in the positive direction, or  -5V  represents 5 volts in the negative direction. We also know that DC power supplies do not change their value with regard to time, they are a constant value flowing in a continuous steady-state direction. In other words, DC maintains the same value for all times and a constant uni-directional DC supply never changes or becomes negative unless its connections are physically reversed. An example of a simple DC or direct cur...

Not all amplifiers are the same and are therefore classified according to their circuit configurations and methods of operation. In “Electronics”, small-signal amplifiers are commonly used devices as they have the ability to amplify a relatively small input signal, for example from a  sensor  such as a photo device, into a much larger output signal to drive a relay, lamp, or loudspeaker for example. There are many forms of electronic circuits classed as amplifiers, from Operational Amplifiers and Small Signal Amplifiers up to Large Signal and Power Amplifiers. The classification of an amplifier depends upon the size of the signal, large or small, its physical configuration, and how it processes the input signal, which is the relationship between the input signal and the current flowing in the load. The type or classification of an amplifier is given in the following table. Classification of Amplifiers Type of Signal Type of Configuration Classification Frequency of Operation S...