Added 555 timer duty cycle and freqency in astable mode.

electronics/IC_555_Timer.py

@@ -0,0 +1,50 @@
+# https://en.wikipedia.org/wiki/555_timer_IC#Astable
+from __future__ import annotations
+
+
+def astable_mode(
+    resistance_1: float, resistance_2: float, capacitance: float
+) -> dist[str:float]:
+    """
+    This function can calculate the frequency and duty cycle of an astable 555 timer.
+    The function takes in the value of the external resistances (in OHMS) and 
+    capacitance (in microFARADS), and calculates the following:
+
+    -------------------------------------
+    | Freq = 1.44 /[( R1+ 2 x R2) x C1] |               ... in Hz
+    -------------------------------------
+
+    ------------------------------------------------
+    | Duty Cycle = (R1 + R2) / (R1 + 2 x R2) x 100 |    ... in %
+    ------------------------------------------------
+
+    Usage examples:
+    >>>astable_mode(resistance_1=45, resistance_2=45, capacitance=7)
+    {'Frequency': 1523.8095238095239, 'Duty_Cycle': 66.66666666666666}
+    >>>astable_mode(resistance_1=356, resistance_2=234, capacitance=976)
+    {'Frequency': 1.7905459175553078, 'Duty_Cycle': 71.60194174757282}
+    >>>astable_mode(resistance_1=2, resistance_2=-1, capacitance=2)
+    Traceback (most recent call last):
+        ...
+    ValueError: All values must be positive
+    >>>astable_mode(resistance_1=0, resistance_2=0, capacitance=2)
+    Traceback (most recent call last):
+        ...
+    ValueError: All values must be positive
+    """
+
+    if resistance_1 <= 0 or resistance_2 <= 0 or capacitance <= 0:
+        raise ValueError("All values must be positive")
+    else:
+        frequency = (1.44 / ((resistance_1 + 2 * resistance_2) * capacitance)) * 10**6
+
+        duty_cycle = (
+            (resistance_1 + resistance_2) / (resistance_1 + 2 * resistance_2) * 100
+        )
+        return {"Frequency": frequency, "Duty_Cycle": duty_cycle}
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()