# Circuit Globe All about Electrical and Electronics

## Regenerative Braking

In Regenerative Braking, the power or energy of the driven machinery which is in kinetic form is returned back to the power supply mains. This type of braking is possible when the driven load or machinery forces the motor to run at a speed higher than no load speed with a constant excitation. Contents: Applications…

## Ward Leonard Method Of Speed Control Or Armature Voltage Control

Ward Leonard Method of speed control is achieved by varying the applied voltage to the armature. This method was introduced in 1891. The connection diagram of the Ward Leonard method of speed control of a DC shunt motor is shown in the figure below. Contents Torque and Power Characteristic Advantages of Ward Leonard Drives Drawbacks…

## Efficiency of DC Generator

Efficiency is simply defined as the ratio of output power to the input power. Let R = total resistance of the armature circuit (including the brush contact resistance, at series winding resistance, inter-pole winding resistance and compensating winding resistance). The efficiency of DC generator is explained below in the line diagram. I is the output…

## Applications of DC Machines

In the present day world, the electrical energy is generated in bulk in the form of an alternating current. Hence, the use of DC machines, i.e., DC generators and motors are very limited. They are mainly used in supplying excitation of small and medium range alternators. The Industrial Applications of DC are in Electrolytic Processes,…

## Losses in DC Machine

The losses that occur in a DC Machine is divided into five basic categories. The various losses are Electrical or Copper losses (I2R losses), Core losses or Iron losses, Brush losses, Mechanical losses, Stray load losses. These losses are explained below in detail. Contents: Electrical or Copper losses Magnetic Losses or Core Losses or Iron…

## Characteristic of DC Generators – Separately Excited Self Excited And Compound Generator

Characteristic is the graph between the two dependent quantities. It shows the steady state characteristic of DC generators. The characteristic of the DC generators explain the relations between the loads, excitation and terminals voltage through graph. Following are the three important characteristics of a DC Generator. Magnetization Characteristic This characteristic gives the variation of generating voltage…

## Starting of DC Motors

A starter is a device to start and accelerate a motor. A controller is a device to start the motor, control and reverse the speed of the DC motor and stop the motor. While starting the DC motor, it draws the heavy current which damages the motor. The starter reduces the heavy current and protects the…

## Power Flow Diagram of DC Generator and DC Motor

The Power Flow Diagram is used to determine the efficiency of a generator or motor. In the below figure of power flow diagram of DC Generator, it is shown that initially the mechanical power is given as an input which is converted into electrical power, and the output which is obtained is in the form of…

## Methods of Improving Commutation

There are three main methods of Improving Commutation or obtaining sparkles Commutation is Resistance and Voltage Commutation and Compensating Winding. Further, the voltage commutation consists of another two methods which are used to produce the injected voltage, named as Commutating poles or Interpoles and Brush Shift. The following methods of Improving Commutation are explained below…

## Speed Regulation of DC Motor

If the load is applied to the DC motor or machine, the speed of the motor decreases automatically. Thus to maintain the constant speed, the difference between no load and full load speed called as Speed Regulation should be maintained very less. The motor is said to at good regulation if they maintian the constant…