Basics of Electrical and Electronic Circuits

In circuits, we think about basic circuit elements that are the “building blocks” of our circuits. This is similar to what we do in Chemistry with chemical elements like oxygen or nitrogen.

A circuit element cannot be broken down or subdivided into other circuit elements. 

A circuit element can be defined in terms of the behavior of the voltage and current at its terminals.

There are 5 basic circuit elements:

1. Voltage sources: A voltage source is a two-terminal circuit element that maintains a          voltage across its terminals. There are 2 kinds of voltage sources:

a)      Independent voltage sources

b)      Dependent voltage sources, of which there are 2 forms:

                                                         i.            Voltage-dependent voltage sources

                                                       ii.            Current-dependent voltage sources

2. Current sources: A current source is a two-terminal circuit element that maintains a current through its terminals. There are 2 kinds of current sources:

a)      Independent current sources

b)      Dependent current sources, of which there are 2 forms:

                                                         i.            Voltage-dependent current sources

                                                       ii.            Current-dependent current sources

3. Resistors(R): A resistor is a two terminal circuit element that has a constant ratio of the voltage across its terminals to the current through its terminals. The value of the ratio of voltage to current is the defining characteristic of the resistor. It obeys Ohm's Law. Where the value of the resistance of the resistor is directly proportional to the potential difference across the resistor and inversely proportional to the current flowing through it.

                               R=V/I  (Ohms)

4. Inductors(L): An inductor or coil or reactor, is a passive two-terminal electrical component which resists changes in electric current passing through it. The inductance (L) results from the magnetic field around a current-carrying conductor; the electric current through the conductor creates a magnetic flux. Mathematically speaking, inductance is determined by how much magnetic flux φ through the circuit is created by a given current (i)

   

  

5. Capacitors(C): A capacitor or a condenser is a passive two-terminal electrical component used to store energy electrostatically in an electric field. An ideal capacitor is wholly characterized by a constant capacitance C, defined as the ratio of charge ±Q on each conductor to the voltage V between them:
   

   

References:

• www.google.com
• www.wikipedia.com
• powerpoint presentations of Dr. Dave Shattuck