When primary terminal of a transformer is excited by a sinusoidal wave, then it results in a sinusoidal waveform of the same frequency with either stepped up or stepped down the voltage at its secondary terminal. The waveform remains the same.
The real question is, whether the waveform at the secondary will remain the same for other alternating signals like a square wave, rectangular wave, triangular wave or not?
Using Fourier series we can decompose the square wave, rectangular wave, triangular wave and all periodic wave-forms to a number of sinusoidal wave-forms with frequencies multiplied by fundamental frequency.
All of these harmonic components pass through transformer, if the transformer is an ideal transformer the output waveform will be as same as the input signal, but if the transformer is a real transformer, in its equivalent circuit the voltage drop across the series leakage inductances is a function of frequency, and for the higher harmonic components, the voltage drop will be higher. This may lead to deforming in the output wave-forms.
And also the harmonic component incorporated with these non-sinosoidal wave-forms lead to higher Foko loss in transformer and as a result higher temperature.
If u want to use these transformation you need to a special kind of Ferrit coil and also need to design the windings with minimum possible leakage inductances.
I believe that there will be an exponential build up of the magnetizing current and then a exponential decay and build up in the opposite direction and this will repeat periodically, based on the period of the applied square or rectangular wave. The flux and induced voltage will accordingly assume the same shape provided there is no saturation. The magnetic material will determine the response time and an impulse train can also be hence expected.
Pulses or Square Wave in output depends on the Time Constant of the Equivalent Resistance and Inductance of the Transformer on No Load and Load,if connected and also the the Period of the Square wave input, as it acts as a Differentiator Circuit.Refer Wave Shaping.
P.S.
The output signal from the transformer secondary could be sinusoidal, because, generation of square wave is through saturation of the operational amplifiers involved in the production of the square wave. As we know, the lines forming square wave are not perfect straight lines but somehow sloppy.
I agree with Pisupati Sadasiva, time constant for both sides, load and pulse duty cycle will affect the shape.
In my opinion, differentiation of the input voltage will take place in transformer. e= -N*d(phi)/dt. As in a square wave the changes in amplitude, takes place only at the side edge of wave form hence transformation action takes place at these edges only. So, during the transition from positive to negative, there will be a pulse in the output. Because of that, the output voltage will be in shape of pulsed wave. That's why the input voltage of a transformer is generally chosen to be sinusoidal. If the input voltage is sinusoidal, the shape of the waveform will remain intact after several differentiation.
Thank you Vishnu A V for your to the point answer.
Also, thanks to Ananyo Bhattacharya for explaining why the output waveform at the secondary will be an impulse signal.
Such transformers will be meant for signal transformation from one circuit to the other and not power, since alternator outputs are always Sine wave. In this case as pointed out earlier, the harmonic components will pass through causing losses and distortion of the resulting waveform. Hence it will not be a replica in a real transformer.
What should be done (regarding hardware & mathematical modelling) in order to get the square wave at the output of the transformer excited by square wave at the primary.
Thanks in advance
The Fourier series transformation of square wave includes both relatively low frequency and very high frequency components. All them will undergo attenuation while transmitting to the secongary winding, at this higher frequency components will undergo higher attenuation. So, I think the transformed square wave will have much more smoother form in comparison with square.
if primary input is sine the flux is sine and hence according to faraday law the the differentiation or derivative of such flux is also sinuside and hence induced emf at the secoundry side is sinuside now take similar condition for square wave which produce square wave flux now take the derivative of square wave and get your output wave type.
Square wave repeaters should be used if in a 2 port network you need a square wave output for a square wave input.....
la forma de onda de salida dependera de la inducccion Bmax adoptada en el calculo del transofrmador. Si la entrada es senoidal la salida solo sera senoidal si el transformador trabaja en la zona lineal de la curva B-H.
Caso contrario se agregan armonicas y hasta podria llegar a obtenrer una square shape waveform.
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