| two-terminal-pair network for which the sum of instantaneous powers at the two-terminal pairs is identically equal to zero and for which the ratio of the input voltage and the output voltage has a constant value K
NOTE 1 – An ideal transformer can be considered as a linear inductive 2-terminal-pair element characterized by a singular inductance matrix.
NOTE 2 – For an ideal transformer, the input voltage u1, the output voltage u2, the input current i1 and the output current i2 are related by the formula:
with the usual reference conventions for associated voltages and currents given for two-port networks in IEC 60375:2003, Clause 7.
NOTE 3 – Under sinusoidal conditions, the impedance Z1 seen at the input port is the product of the terminating impedance Z at the output port by the square of the constant K:
Z1 = K2Z
NOTE 4 – An ideal transformer is a circuit element that neither stores nor dissipates energy. The transformer as a device is defined in IEC 60050-151.