current of the battery , but not through the output of the transformer but between the input and the battery, why is that?
The input winding coil is acting like an inductor. You will get a momentary surge that can show a high voltage. Without AC nothing exciting will happen on the transformer secondary.
DC does not work on a transformer. Only AC. Putting DC into a transformer is like shorting the battery out. A transformer works by magnetic flux which is caused by the change in voltage (AC).
An ideal transformer is a equal voltage per turn device. If the secondary winding has 28/115 times the number of turns as the primary winding then it will produce 28/115 as much voltage as that applied to the primary. But an ideal transformer is also a power in equals power out device, so that the product of primary voltage times primary current equals the product of secondary voltage times secondary current. So the secondary current will be 115/28 times the primary current. -- Regards, John Popelish
A transformer works with AC current only. AC current makes the magnetic field in the primary coil expand and collapse. The secondary coil picks it up and produces AC current at a different voltage/current ratio, depending on the copper wire windings. When you induce direct current from a battery. All it does is create a flow through the primary coil with a steady magnetic field. The steady magnetic field does not create any current in the secondary coil. Hope this helps. Kind of difficult to explain without pictures.
I don't really understand your question but I think you are talking about Induced EMF (EMF means voltage). Contrary to popular belief, applying a DC source to a coil will cause something momentary to happen. When you initially connect the battery to the coil (transformer), current will begin to flow. This flow of current creates a magnetic field (flux) around the conductor (wire). As current flow in the conductor increases from zero to maximum, the flux density of the surrounding field will also increase. When the current reaches a steady state, the flux density is also at a steady state. It is the changing current that causes the changing flux, which in turn creates a voltage in nearby conductors. Once the current has reached its' steady state (stopped changing), flux stops changing nearby conductors are not affected. When the battery is disconnected, the same will occur as the current decreases to zero. In summary; If you connect an ammeter in series with your battery transformer, you would see an initial high current flow, which would quickly reduce to a lower steady state. If you put a voltmeter across the transformer, you would see an initial voltage spike until the current reaches steady state. Also, if you were to attach a voltmeter to the secondary winding of the transformer, you would see an initial voltage spike when you connected the battery to the primary. You would see the same thing happen when you disconnect the battery except the voltages will be reversed. Lenz's Law (a bit like Newtons 3rd law). The direction of an induced EMF is such that the resulting current flow will produce a magnetic field, which tends to oppose the original motion causing the induced EMF. This is how the ignition coil in older cars works. Cars do not use ACthey use DC.
