Transformers are used to transfer energy from one circuit to a different by suggests that of a standard magnetic field. Altogether cases except auto transformers, there’s no direct electrical association from one circuit to the opposite.
When an A.C flows in a very conductor, a magnetic field occurs round the conductor, as illustrated in Figure: I If another conductor is positioned within the field created by the 1st conductor such the flux lines link the 2nd conductor, as shown in Figure, then a Voltage is induced into the 2nd conductor. The employment of a magnetic field from 1st to induce a voltage into a 2nd coil is that the principle on that transformer concept and application is predicated.
Air Core electrical device:
Some small transformers for low-power applications are made with air between the 2 coils. Such transformers are inefficient as a result of the proportion of the flux from the first coil that links the second coil is little.
At a time once the applied voltage to the coil is E and the flux linking the coils is Ø lines, the instantaneous voltage of the obtainability is:
e = √2Ecosωt = N dØ/dt 108 ---> (2)
Since the quantity of flux linking the 2nd coil may be a little proportion of the flux from the 1st coil, the voltage induced into the 2nd coil is little. The quantity of turns may be raised to extend the voltage output, however this may increase prices. The necessity then is to extend the quantity of flux from the 1st coil that links the 2nd coil.
The voltage induced within the 2nd coil is set as follows.
E = N dØ/dt 108 --->(1)
Where ‘N’ is the no. of turns in the coil,
dØ /dt is the time rate of change of flux linking the coil, and
Ø is the flux in lines.
dØ/dt = (√2cosωt 108)/N --->(3)
The maximum value of is given by:
Using the MKS (metric) system, where Ø is the flux in Webbers,
E = N dØ /dt ---> (5)
And
Ø = (2E)/ (2πf N) ---> (6)
Since the quantity of flux linking the 2nd coil may be a tiny proportion of the flux from the 1st coil, the voltage induced into the 2nd coil is little. The no. of turns may be augmented to extend the voltage output, however this can increase prices. The requirement then is to extend the quantity of flux from the first coil that links the 2nd coil.
Oct 1, 2013
0
Comments
