Skip to main content

300x250 Ads

Motor

By Ashik

Principle:
    It is based on the principle that when a current-carrying conductor is placed in a magnetic field, it experiences a mechanical force whose direction is given by Fleming's Left-hand rule and whose magnitude is given by
                     Force, F = B I l newton     
                       Where B is the magnetic field in weber/m2.
                                 I is the current in amperes and 
                                 l is the length of the coil in meter.             
The force, current and the magnetic field are all in different directions. 
    If an Electric current flows through two copper wires that are between the poles of a magnet, an upward force will move one wire up and a downward force will move the other wire down.




undefined    undefined
Figure 1: Force in DC Motor
Figure 2 : Magnetic Field in DC Motor
Figure 3 :  Torque in DC Motor
Figure 4 : Current Flow in DC Motor
    The loop can be made to spin by fixing a half circle of copper which is known as commutator, to each end of the loop. Current is passed into and out of the loop by brushes that press onto the strips. The brushes do not go round so the wire do not get twisted.  This arrangement also makes sure that the current always passes down on the right and back on the left so that the rotation continues. This is how a simple Electric motor is made.


Download the pdf file

Labels:

Comments

Post a Comment

Popular posts from this blog

Propagation-Radio-Waves

By Ashik
Radio Wave Propagation types
Post a Comment
Read more

Armature Winding ,Pole Pitch, Coil Span, Commutator Pitch

By Ashik
Now we are going to discuss about armature winding in details. Before going through this section, we should understand some basic terms related to armature winding of dc generator . Pole Pitch Definition of Pole Pitch The pole pitch is defined as peripheral distance between center of two adjacent poles in dc machine. This distance is measured in term of armature slots or armature conductor come between two adjacent pole centers. This is naturally equal to the total number of armature slots divided by number of poles in the machine. If there are 96 slots on the armature periphery and 4 numbers of poles in the machine, the numbers of armature slots come between two adjacent poles centers would be 96/4 = 24. Hence, the pole pitch of that dc machine would be 24. As it is seen that, pole pitch is equal to total numbers of armature slots divided by total numbers of poles, this can alternatively referred as armature slots per pole . Coil Span or Coil Pitch Coil of ...
Post a Comment
Read more

8255 Programmable Peripheral

By Ashik
8255 Programmable Peripheral Interface (PPI) Intel 8255A is a general purpose parallel I/O interface. The peripheral devices are slower than the microprocessor. PPI makes an inter-relation between microprocessor and peripheral devices. It provides three I/O port (Port A, Port B and Port C) and can be programmed as a) Simple Parallel I/O (No handshaking) b) Simple Strobe I/O (Use STB handshake) c) Single Handshake I/O (Use STB-ACK handshake) d) Double handshake I/O (Uses STB-ACK and STB-ACK) Handshaking and Handshaking Signal The making of inter relation between slower peripheral device and microprocessor is called handshaking. Before making the inter-relation between peripheral device and microprocessor the PPI send some signals to microprocessor and peripheral device to perform the process, these signals are called handshaking signal. 8255-based devices that perform handshaking support four handshaking signals: • Strobe Input (STB) • Input Buffer Full (IBF) • ...
Post a Comment
Read more

Add