Electronic – Shape current through coil

coilfourierpassive-networks

Suppose I have a simple RL-circuit with known resistance R and, inductance L with a voltage source where I can apply any input voltage (via an arbitrary waveform generator).
What I want now is a specific shaped current through the coil (I need the b-field), for example the convolution of a rectangle signal with a cosine (i.e. half cycle of a cosine). What voltage do I have to apply to get the desired current through the coil.

I'm pretty sure it is possible to calculate it with the response function and several Fourier-transformations, but I'm unfortunately not an expert in this area.

Best Answer

Given the context, I assume you have this:

schematic

^{simulate this circuit – Schematic created using CircuitLab}

There is a series current \$i(t) \$ and so, by KVL:

$$v_1(t) = Ri(t) + L \frac{di(t)}{dt} $$

What voltage do I have to apply to get the desired current through the coil.

Since the desired current is just \$i(t)\$ and is given, the equation above is all you need assuming the time derivative of the desired current exists.

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