charging_inductor (#10427)

* charging_capacitor

* charging_capacitor

* Final edits

* charging_inductor

---------

Co-authored-by: Christian Clauss <cclauss@me.com>

electronics/charging_inductor.py

@@ -0,0 +1,96 @@
+# source - The ARRL Handbook for Radio Communications
+# https://en.wikipedia.org/wiki/RL_circuit
+
+"""
+Description
+-----------
+Inductor is a passive electronic device which stores energy but unlike capacitor, it
+stores energy in its 'magnetic field' or 'magnetostatic field'.
+
+When inductor is connected to 'DC' current source nothing happens it just works like a
+wire because it's real effect cannot be seen while 'DC' is connected, its not even
+going to store energy. Inductor stores energy only when it is working on 'AC' current.
+
+Connecting a inductor in series with a resistor(when R = 0) to a 'AC' potential source,
+from zero to a finite value causes a sudden voltage to induced in inductor which
+opposes the current. which results in initially slowly current rise. However it would
+cease if there is no further changes in current. With resistance zero current will never
+stop rising.
+
+'Resistance(ohms) / Inductance(henrys)' is known as RL-timeconstant. It also represents
+as τ (tau). While the charging of a inductor with a resistor results in
+a exponential function.
+
+when inductor is connected across 'AC' potential source. It starts to store the energy
+in its 'magnetic field'.with the help 'RL-time-constant' we can find current at any time
+in inductor while it is charging.
+"""
+from math import exp  # value of exp = 2.718281828459…
+
+
+def charging_inductor(
+    source_voltage: float,  # source_voltage should be in volts.
+    resistance: float,  # resistance should be in ohms.
+    inductance: float,  # inductance should be in henrys.
+    time: float,  # time should in seconds.
+) -> float:
+    """
+    Find inductor current at any nth second after initiating its charging.
+
+    Examples
+    --------
+    >>> charging_inductor(source_voltage=5.8,resistance=1.5,inductance=2.3,time=2)
+    2.817
+
+    >>> charging_inductor(source_voltage=8,resistance=5,inductance=3,time=2)
+    1.543
+
+    >>> charging_inductor(source_voltage=8,resistance=5*pow(10,2),inductance=3,time=2)
+    0.016
+
+    >>> charging_inductor(source_voltage=-8,resistance=100,inductance=15,time=12)
+    Traceback (most recent call last):
+        ...
+    ValueError: Source voltage must be positive.
+
+    >>> charging_inductor(source_voltage=80,resistance=-15,inductance=100,time=5)
+    Traceback (most recent call last):
+        ...
+    ValueError: Resistance must be positive.
+
+    >>> charging_inductor(source_voltage=12,resistance=200,inductance=-20,time=5)
+    Traceback (most recent call last):
+        ...
+    ValueError: Inductance must be positive.
+
+    >>> charging_inductor(source_voltage=0,resistance=200,inductance=20,time=5)
+    Traceback (most recent call last):
+        ...
+    ValueError: Source voltage must be positive.
+
+    >>> charging_inductor(source_voltage=10,resistance=0,inductance=20,time=5)
+    Traceback (most recent call last):
+        ...
+    ValueError: Resistance must be positive.
+
+    >>> charging_inductor(source_voltage=15, resistance=25, inductance=0, time=5)
+    Traceback (most recent call last):
+        ...
+    ValueError: Inductance must be positive.
+    """
+
+    if source_voltage <= 0:
+        raise ValueError("Source voltage must be positive.")
+    if resistance <= 0:
+        raise ValueError("Resistance must be positive.")
+    if inductance <= 0:
+        raise ValueError("Inductance must be positive.")
+    return round(
+        source_voltage / resistance * (1 - exp((-time * resistance) / inductance)), 3
+    )
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()