Not at all. You'll need to study transformer magnetics first. Primary current "due to" the primary voltage source is called magnetizing current and it establishes the flux in the core. When we say VpIp=VsIs, Ip is the reflected secondary current, an extra current drawn from supply to totally cancel out the demagnetizing action of secondary mmf and maintain constant flux in the core(the one produced by magnetizing current). Magnetizing current is very very small compared to Ip, hence is neglected in explanations about the transformer. For power transfer, Ip is responsible. Get any good electrical machinery book and you'll see all these things explained in detail.AsrielDreemurr said:Are the equations P=VI and V=RI contradictory?
Not when you realize that the effect of a transformer is to modify (transform) the Resistance of the load to a different value, as seen by the supply. In order to understand this you have to get the causes and effects in the right order. The produce VI will be unchanged but the R of the load will determine the current through it for a given secondary Volts. The Load Current times the Secondary Volts is the Power dissipated and so is the Supply Current times the Primary Volts.AsrielDreemurr said:Are the equations P=VI and V=RI contradictory?
Increase the voltage vs what? Was the circuit run without a transformer before the transformer was installed? What was the current then?AsrielDreemurr said:How can a transformer increase the voltage yet lower the current? Are the equations P=VI and V=RI contradictory?
AsrielDreemurr said:How can a transformer increase the voltage yet lower the current?
Ohm's law states that the current through a conductor is directly proportional to the voltage across it, for a given temperature. However, transformers are not simple conductors and their operation involves more complex principles of electromagnetism.
Transformers violate Ohm's law because they have two separate circuits, the primary and secondary, which are connected by a magnetic field. This magnetic field causes a change in the voltage and current between the two circuits, making it difficult to apply Ohm's law to the overall system.
There are several factors that contribute to the non-applicability of Ohm's law to transformers. These include the presence of a magnetic field, the varying number of turns in the coils, and the differences in impedance between the primary and secondary circuits.
The magnetic field in transformers plays a significant role in their operation and causes a change in the voltage and current between the primary and secondary circuits. This makes it difficult to determine the resistance or impedance of the overall system, which is necessary for applying Ohm's law.
While Ohm's law may not be applicable to the overall operation of transformers, it can still be used to calculate the current and voltage within each individual circuit (primary and secondary). However, it cannot be used to determine the overall behavior of the transformer as a whole.