Category: Electrical Machines

Covers various types of Electrical machines: The working principles, operation, and applications of the different types of  Motors, Generators and Transformers.

Fuses & Circuit Breakers vs. Overload Heaters for Industrial Motor Protection

A key component of any motor control circuit is some kind of device to detect a condition of excessive overload and interrupt the power to the motor before thermal damage occurs to it. An overload heater is a simple and … Read more

Permanent Magnet DC Motors – Operation & Applications

Permanent magnet dc motors employ a permanent magnet instead of stationary field winding (as with the case of some other types of dc motors) for producing the required magnetic flux. These stationary magnets are normally fixed to the outer shell … Read more

How solid-state soft starting of Induction motors is done

Solid-state soft starting is the most commonly used technique for starting induction motors. It provides a smooth build-up of current and torque; the maximum current and acceleration time are easily adjusted. The only problem with this technique over conventional starters … Read more

Basic Features of Autotransformer Starter

A 3-phase autotransformer is typically employed where star or delta starting provides insufficient starting torque. Each phase of an autotransformer consists of a single winding on a laminated core. This incoming supply is connected across the ends of the coils, … Read more

Types of AC Motors

The AC motors works by rotating the stator field, they make use of the natural alternating nature of the AC wave to turn the field coils on and off sequentially. Generally, AC motors can be classified into two groups: single-phase … Read more

Direct-on-line (DOL) Starter

Let’s consider an illustration of a typical three-phase direct-on-line (DOL) starter below:

Direct-on-line (DOL) starter
Figure 1 Three-phase direct-on-line starter

When the start button is pressed, the 415V contactor coil is energized, the main and auxiliary contacts close, and the motor starts. The … Read more

How cycloconverter is used as a direct frequency converter

The cycloconverter provides direct ac to ac transformation with control over both the output voltage magnitude and output frequency. It employs phase-angle-controlled bridges to synthesize voltages.

The most common form is the three-phase to three-phase converter illustrated below:

… Read more

AC vs DC Power & Motors –  Differences and Benefits

AC and DC power isn’t new and yet it has been two main types of power we are taking advantage of even in the modern age we live in.

But did you ever understand the difference between AC and DC … Read more

What is the difference between a Power transformer and a Distribution Transformer?

Introduction

The transformer, in simple terms can be defined as the voltage regulator. It helps in stepping up and stepping down of the voltages. We all have seen transformers in our locality, where the current is passed from higher voltage … Read more