Indepth Electrical engineering

Inverters are now integral part of every household. As they serve the better and cheap source of supply in case of power cuts. Earlier days Diesel generators were most widely used for household in case of power cuts. There is always curiosity that how an inverter works. Working Principle:- In inverter Alternating supply is first converted into DC supply then again into alternating supply that is why it’s name is inverter. There is obvious question in mind that why there is need for conversion into DC?? Answer for the same is that for inverter working Battery is required which is needed to be charged through DC when power source is available and when power supply  wasn't  available that DC power supply which is stored by Battery is reconverted into AC supply through it’s inverter action. Also when power supply is available then there is no need for Inverter action in that case all points which were on inverter will be charged through power supply. Mean...

Earthing is used to protect both human and  equipment's  from abnormal currents. These abnormal currents will get dissipated safely when properly conducted to earth via the electrode. There are three components to the resistance:- 1.       Resistance of the electrode materials 2.       Contact resistance between the electrode and the soil surrounding it 3.       Resistance of the surrounding earth. The contact resistance between earth and the electrode is minimal if the electrode materials Cleaned properly and unpainted.  Even if steel get rusted even then rusted steel ground rods have little contact resistance because the iron oxide readily soaks up water and has less resistance than most soils. It has been found that the resistance of the surrounding earth will be the largest of the three components as described above. A proper earthing system generally works on the system that an earth ele...

🧰 How a Digital Multimeter (DMM) Works: A Complete Guide Digital multimeters (DMMs) are among the most widely used tools in electrical and electronic industries. They measure voltage, current, resistance, capacitance, and several other parameters. Despite being around for decades, many still find it difficult to understand how a digital multimeter actually works . This guide breaks it down step by step, focusing on the fundamentals, working principle, and measurement flow inside a DMM. ⚡ Fundamentals of DMM Operation Core Principle: Every measurement in a DMM is derived from voltage measurement . Conversion: This voltage is digitized using an Analog-to-Digital Converter (ADC) , most commonly a Successive Approximation Register (SAR) ADC . Why SAR ADC? High resolution (12–16 bits typical). Adequate speed for precision measurements. Simple, stable, and cost-effective. 🔎 Working of SAR ADC in a DMM Sample & Hold: Input voltage is sampled and hel...

Surge Arresters: Types, Working, and Applications Surge arresters are one of the most important protective devices in electrical systems. They work on the same principle as lightning arresters —providing a low-impedance path to earth for transient overvoltages or lightning strikes, and then quickly restoring the circuit back to normal operating conditions. 👉 Think of a surge arrester like a safety relief valve in a boiler or hot water heater. When pressure (voltage) exceeds safe limits, the valve (arrester) opens and safely releases it to ground. Once the voltage returns to normal, the arrester resets and is ready for the next surge. Functions of a Surge Arrester Provide a discharge path – Allow transient overvoltage (spike/surge) to pass to ground. Prevent follow current – Stop continuous current from flowing to ground after the surge has passed. Types of Surge Arresters 1. Expulsion Type Arrester Uses a series spark gap in a fiber tube. When a s...

Lightning arrester is nothing more than a spark air gap with one side connected to a line conductor and the other side connected to earth. When the line-to-ground voltage reached the spark-over level, the voltage surge would be discharged to earth. The modern metal oxide arrester provides both excellent protective characteristics and temporary overvoltage capability. The metal oxide disks maintain a stable characteristic and sufficient non-linearity and do not require series gaps Current level in a Lightning Stroke, Current levels in lighting stokes is as below:- 1 percent'of strokes exceed 200 000 A 10 percent of Strokes Exceed 80 000 A 50 percent of Strokes Exceed 28 000 A 90 percent of Strokes Exceed 8 000 A 99 percent of Strokes Exceed 3 000 A The current in the majority of earth flashes is from the negatively charged cells and the flash current is, thus, a negative Row from cloud to earth there will be lighting strokes from positive charged cell but they are ...

Air conditioning as names 'states' the conditioning of air. Air conditioner not only cools down the air , but also reduces humidity, or the moisture content. All air conditioners work exactly the same manner whether they're installed in a a vehicle, or in a building. Freezer or the refrigerator is an air conditioner too. Air conditioning is an area inside it's own right, but we'll adhere to the principal points or an automobile's air conditioning and the main parts used and a number of hints to keep the air-con system running properly. There's energy used in removing moisture and the heat from the air in the automobile, and petrol is consumed by this because of the additional engine load. The main principles of air conditioning are Evaporation and Condensation, then Compression and Expansion. To physicists and the engineer they talk of thermodynamics - but it 'll be explained by us in our own manner here:  Below is schematic diagram for ex...

Thermal overload relays play a very important for protection of motors and generators both. It should be very interesting to know how an Thermal overload works as all over load relays have same working principle. Thermal motor overload protection relays feature bi-metal strips jointly with a trip mechanism in a casing made of insulating material. Whenever there is overload The motor current heats the bi-metal strips, making them bend and activating the trip mechanism after a particular interval which is based on the current- setting. The release mechanism actuates an auxiliary switch that breaks the motor contactor's coil circuit as shown in circuit diagrams below. A changing position indicator signals the condition "tripped". Above diagrams shows where overload is connected in motor circuit. You may see that in Control circuit overload relay comes first in line but in power circuit it comes at last in line. Question arises why this is done?? This al...