Electrical World

Delta Connection            A delta connection is a connection used in a three phase electrical system in which three elements in series form a triangle ,the supply being input and output at the three junctions.            It is also known as 3 phase 3 wire system.It is preferably used in AC transmission.It is denoted by  Δ . The other name of delta connection is Mesh connection .               In case of Delta connection all the three coils are connected in series to form a close circuit.From each junction we take out one wire and out-going current from each junction assumed to be positive.In case of delta connection it look like a short circuit but in case of balance load the sum of all voltage should be zero.              In the following fig. all values Current,Voltages and power for 3 phase delta connection can be shown. fig ...

Star Connection           Star Connections is a method of connecting pohyphase circuit is such a way that one end of each phase line is connected to a common neutral point that may be connected to the earth as protection against lighting or to a wire to which all the other neutral points of the system are connected.            It is also known as three phase four wire system.It is denoted by Y.It is the most preferred system for AC power distribution.            If we connect the balance load across three phase voltage system in parallel,then the three currents will be flow in neutral and their quantities will be same .The angle between them is 120º.So we can say That the sum of all currents is zero.                                                       ...

Working Principle of DC Motor            An electrical motor is a machine which converts electrical energy into mechanical energy( There is no basic difference between DC generator and a DC motor.The DC motor can be used as a DC generator).             The working principle of DC motor is based on ,when a current carrying conductor is placed in a magnetic field it experiences a mechanical force whose direction is given by the Fleming's left hand rule and its magnitude is F=BIl newton. Working of DC Motor       Fig. Is shown a portion of the muiltipolar DC motor. fig. When the field magnets are exited and we supplied current from the main supply to the armature conductors.\the the armature experience a force which tries to rotate it.Armature conductors under N-pole are assumed to carry current downwards ant the conductors under S-pole carries current upwards.By using Fleming's left hand rule we ca...