charging_capacitor

Author: dhruvtrigotra

Diff for: electronics/charging_capacitor.py

@@ -0,0 +1,106 @@
+# source - The ARRL Handbook for Radio Communications
+
+from math import exp  # value of exp = 2.718281828459…
+
+"""
+Description
+-----------
+when a capacitor is connected with a potential source(AC or DC). It is starts to charge
+at a general speed but when a resistor is connected in the  circuit with in series to
+a capacitor then the capacitor charges slowly means it will take more time than usual.
+while the capacitor is being charged, the voltage is in exponential function with time.
+
+in the this function there is RC which is 'resistance(ohms)*capacitance(farads)'.
+also represented as τ (tau).
+
+with the help of RC-timeconstant we can find the voltage at any time 't' from the
+initiation of charging a capacitor with the help of the exponential function
+containing RC.Both at charging and discharging of a capacitor.
+"""
+
+
+def charging_capacitor(
+    source_voltage: float,  # voltage in volts.
+    resistance: float,  # resistance in ohms.
+    capacitance: float,  # capacitance in farads.
+    time_sec: float,  # time in seconds after charging initiation of capacitor.
+) -> float:
+    """
+    find voltage of capacitor at any nth second after the initiation of it's charging.
+
+    Parameters
+    ----------
+    source_voltage : float
+        it is going to multiply with rest of the function.
+    resistance : float
+        it is using in RC function.
+    capacitance : float
+        it is multiplying with resistance_ohms to yield output.
+    time_sec : float
+        it is dividing by RC.To find the voltage at nth second.
+
+    Examples
+    --------
+    >>> charging_capacitor(source_voltage=15,resistance=200,capacitance=20,time_sec=2)
+    0.007
+
+    >>> charging_capacitor(source_voltage=0,resistance=1000,capacitance=30,time_sec=3)
+    Traceback (most recent call last):
+        ...
+    ValueError: source voltage cannot be zero.
+
+    >>> charging_capacitor(20,2000,30*pow(10,-5),4)
+    19.975
+
+    >>> charging_capacitor(source_voltage=20,resistance=-2000,capacitance=30,time_sec=4)
+    Traceback (most recent call last):
+        ...
+    ValueError: Resistance cannot be negative.
+
+    >>> charging_capacitor(source_voltage=-2,resistance=20,capacitance=30,time_sec=4)
+    Traceback (most recent call last):
+        ...
+    ValueError: source voltage cannot be negative.
+
+    >>> charging_capacitor(source_voltage=8,resistance=0,capacitance=30,time_sec=4)
+    Traceback (most recent call last):
+        ...
+    ValueError: Resistance cannot be zero.
+
+    >>> charging_capacitor(source_voltage=30,resistance=1500,capacitance=0,time_sec=4)
+    Traceback (most recent call last):
+        ...
+    ValueError: Capacitance cannot be zero.
+
+    >>> charging_capacitor(source_voltage=30,resistance=23,capacitance=-40,time_sec=5)
+    Traceback (most recent call last):
+        ...
+    ValueError: Capacitance cannot be negative.
+    """
+
+    if source_voltage <= 0:
+        if source_voltage < 0:
+            raise ValueError("source voltage cannot be negative.")
+        elif source_voltage == 0:
+            raise ValueError("source voltage cannot be zero.")
+    elif resistance <= 0:
+        if resistance < 0:
+            raise ValueError("Resistance cannot be negative.")
+        elif resistance == 0:
+            raise ValueError("Resistance cannot be zero.")
+    elif capacitance <= 0:
+        if capacitance < 0:
+            raise ValueError("Capacitance cannot be negative.")
+        elif capacitance == 0:
+            raise ValueError("Capacitance cannot be zero.")
+    else:
+        return round(
+            source_voltage * (1 - exp(-time_sec / (resistance * capacitance))),
+            3,
+        )
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()