Speed Control of DC Motor by Varying Field Flux

In previous post “Speed Control of DC Motor” we discussed the method of speed control of DC Motor by Armature Circuit Resistance Control Method. In this post we will discuss the method of speed control of DC Motor by varying the Field Flux which is known as Field Weakening Method. By Field Weakening Method of … Read more

Speed Control of DC Motor

DC Motor speed control means to have full control on the speed of DC Motor. The variation in speed of DC Motor because of variation in load is not the speed control. Therefore intentional variation in speed of DC Motor is called Speed Control. As we know that for a DC Motor having armature resistance … Read more

Voltage Build up in DC Shunt Generator

In this post we will discuss how Voltage is Build up in DC Shunt generator at No Load. Consider a DC Shunt Generator at no load as shown in figure below. The switch in the field circuit is supposed open and the armature of DC Shunt Generator is driven at rated speed. Because of presence … Read more

Why DC Series Motor should not be Started at No Load?

In this post we will discuss about the Speed Current Characteristics of DC Series Motor. After going through this post ask yourself the answer of the question “Why DC Motor should not be Started at No Load?” I am sure that you will be able to answer. In DC Series Motor the field winding remain … Read more

Three Point DC Motor Starter

Three Point Starter for DC Motor have three point for electrical connection namely Line (L) to which positive / negative terminal of DC Voltage is connected, Field (F) which is connected to the field winding of DC Motor and Armature which is connected to the Armature of DC Motor. As it is having three points for … Read more

DC Shunt Motor Charatersitics

Long Shunt and Short Shunt DC Compound Machine: In short shunt DC Compound Machine, shunt filed winding is connected across the Armature whereas in Long shunt connection it is connected across the line terminal. But there is no difference in operating characteristic in two types of machine. DC Shunt Generator Characteristics: There are four basic … Read more

DC Motor Starter

D. C Motor Starting:   Why Starter Needed:   Let Vt  = Terminal Voltage Ia = Armature Current ra = Armature Resistance Ea = Back emf = KaØWm At the time of starting, speed of motor is zero hence Wm = 0, therefore there will not be any Back / Counter emf. Hence if we … Read more