DC Machine

Advantages:The series motor has the highest starting torque for a given power rating. When the motor is overloaded, the speed drops and the torque increases. While delivering high torque during an overload, the series motor draws less current and power from the source compared to a shunt or compound DC ...
Read More
Servomechanism is a powered mechanism producing motion or forces at a higher level of energy than the input level, e.g. in the brakes and steering of large motor vehicles, especially where feedback is employed to make the control automatic.A servomechanism, sometimes also called Servo, is an automatic device that uses ...
Read More
DC Machines can be tested by three different methods namely Direct Method, Indirect Method and Regenerative Method. Direct Method of testing of DC Machine, also known as Brake Test (if carried out for a DC Motor) will be discussed in this post. Direct method is suitable for small DC machines ...
Read More
What is a Brushless DC or BLDC Motor? A Brushless DC Motor Motor accomplishes commutation electronically using rotor position feedback to determine when to switch the current. This motor is electrically commutated by power switches instead of brushes. The structure of Brushless DC Motor is shown in figure below. In ...
Read More
D. C Motor Starting:Why Starter Needed:Let Vt = Terminal VoltageIa = Armature Currentra = Armature ResistanceEa = Back emf = KaØWmAt the time of starting, speed of motor is zero hence Wm = 0, therefore there will not be any Back / Counter emf. Hence if we look into the ...
Read More
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.Characteristics of DC Shunt Generator:There ...
Read More
As discussed in earlier post, Purpose of Interpole in DC Machine, there are two types of effect of armature reaction on the main field flux: 1) Distortion in Main Field Flux 2) Net reduction of Main Field Flux Due to the above two effects of armature mmf, there are many ...
Read More
When there is a change in magnetic flux linkage through a conducting loop, an emf is developed as per the Farady’s Law of Electromagnetic Induction. Generators use Electromagnetic Induction to convert mechanical energy into electrical energy. In an AC, or alternating current, Generator, the electrical current periodically reverses its direction ...
Read More
A commutator in a DC Machine has alternate bands of Copper and mica. Now when the armature starts to rotate by an external force (in DC Generator), the coils situated in the armature also rotate. The coils are shorted via brush segment with alternate change in influence of poles. This ...
Read More
There are two types of winding in a Conventional DC Motor, namely Filed Winding and Armature Winding. The purpose of Field Winding is to produce the working magnetic flux in the air gap and wound on the stator of the motor whereas armature winding is wound on the rotor. But ...
Read More