Answer / e venkat reddy

if u apply DC voltage to transformer,
reactive load whose formula is
Xl=2*phi*f*L
In pure dc the frequency is zero so inductive reactance is
zero and the resistance of transformer is very small ie .2
to .4 ohms. if u apply 230v DC then the current will be
230/.4= 575 amps so that it is going to burn winding of the
transformer. so we use transformer only for AC voltage.

Answer / glen saldanha

it depend whether it is dc pulsating or pure dc waveform

as transformer is a reacive load whose formula is
Xl=2phi f L
In pure dc the frequency is zero so it is as good as a
short circuit but in case of pulsating dc as frequency is
known it will definately produce a dc pulsating at the
secondary of the transformer output.Example in SMPS of your
computer these transformer are used.

Answer / ranjith

The principle involved in working of a transformer is
mutual induction. Both electrical and magnetic energy are
interchangeable.
Simply saying change in magnetic field creates emf.
i.e., if flux linking with a coil changes due to the
current flowing in the same coil, then the type of emf
induced is called self induce emf.
Similarly if the flux linking with the coil is changing due
to the current flowing in another coil, then the type of
emf induced is called mutually induce emf. This is the
principle involved in transformer.
The transformer has two windings namely low voltage (L.V)
and high voltage (H.V). These two coils (windings)
magnetically coupled but electrically isolated. The
connection between these two coils existing when there is a
change in flux which is only set up by AC. This is not the
case in that of DC.
Dc means no change in flux-> no emf -> no coupling between
two coils.
So the winding which we give supply is just seems to be
short circuited. So if the resistance is not capable to
oppose the current-> high current-> coil burns.
What will happen if I apply DC to AC transformer?
Theoretically not works
But practically the transformer will burn. It may be
varying for rating of the transformer also.
Transformer means it is for ac only
No need to say it as ac transformer.

Answer / razif mat saat

Short Answer: Nothing will happen

Long Answer: Transformer reacts in AC since the working principle is induction by primary coil to the secondary coil (giving step-up or step down VOLTAGE, depending on number of coil turns in them)

This induction happens if you have rate of change in voltage i.e AC, or at the start of your termination of your DC (from 0V to whatever your DC voltage).

Therefore, in your case, the transformer will act as a transformer only at the beginning of the DC connection (well, think: when you disconnect also...)

During steady state when the DC has stabilized, nothing will happen because there's no rate of change in voltage anymore.

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