The Zener diode was used in its reverse bias. The Zener diode was basically used to produce a stabilized voltage output with low ripple under varying load current. The observed charging current varied between 0 mA and 10 mA. By passing a small current through the diode, close to 0 A, from a voltage source, the Zener diode conducts enough current to maintain a voltage drop at Vout. Zener diode as a voltage regulator, clipping circuits are used to remove the part of a signal that is not defined; while clamp circuits are used to shift an input signal by a value defined by an independent voltage.