Basic laws of Electronics

This post is about refreshing some of the basics concepts in electronics which is being used by all electronic designers in daily work,

Ohm’s Law:

The amount of current through a conductor is directly proportional to the voltage applied across it for any given temperature.

Polarity of Voltage drop:

• Polarity of voltage drop is determined by the direction of flow of electrons.
• Negative (-ve) for electron entering
• Positive (+ve) for electron exiting

Kirchoff’s Voltage Law:

• Algebraic some of all voltages in a loop is equal to zero.

Kirchoff’s Current Law:

•  Algebraic some of all currents entering and exiting a node is equal to zero.

 Voltage Divider Rule:

• The source voltage (V) is divided across the resistors and the voltage drop across a particular resistor (Rx) is given as below,

 Vx = V*(Rx/Rt)

Rt = Total Resistance

Vx = Voltage across the Resistor Rx

Current Divider Rule:

• The current (I) is divided among branches in a parallel circuit.The current in a particular branch is calculated as below,

In the reference Fig. current through R1 is calculated.

Introduction to Electronics Engineering

The most important core engineering fields are Civil, Mechanical and Electrical. In ancient days most of the engineering products are based on mechanics only which uses engines, gears, wheels and belts. When the electrical power and motors discovered the usage of electric power took place important place. Once the transistors invented the field of electronics started to get the attention.

The important advantage of electronics is control of  a particular application becomes easy. It increases the compactness, accuracy and precision of the products.

The major classifications of electronics are,

1. Analog
2. Digital
3. Power

Mostly all the real time outputs are analog (amplitude vary with respect to time). This real time analog signals needs to be processed by digital electronics circuitry, so it is necessary to convert those analog signals into digital in order to make them acceptable by digital circuits.

Digital circuits process the inputs and make decisions as per the predefined conditions. If it is necessary then again the digital output needs to be converted to analog to make real time controls.

Power electronics is the part of electronics which deals about the conversion of incoming AC input voltage to DC voltage. (All the semiconductors are operating in DC power).

An Electronics engineer should have basic knowledge of analog, digital and power and he should be expertise on at least one of the fields.

Nowadays since the operating frequency of electronics circuits increases to MHz/GHz an electronic engineer should be aware of EMI/EMC.