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Characteristics of zener diode

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  Aim:  To find out the forward and reverse characteristics of zener diode. Instrument required : zener diode 5.1v, resistor 220E, voltmeter, current meter, breadboard , connecting wires.  Theory: A Zener diode is a highly doped semiconductor device specifically designed to function in the reverse direction. It is engineered with a wide range of Zener voltages (Vz), and certain types are even adjustable to achieve variable voltage regulation. The Zener diode operates just like the normal diode when in the forward-bias mode, and has a turn-on voltage of between 0.3 and 0.7 V. However, when connected in the reverse mode, which is usual in most of its applications, a small leakage current may flow. As the reverse voltage increases to the predetermined breakdown voltage (Vz), a current starts flowing through the diode. The current increases to a maximum, which is determined by the series resistor, after which it stabilizes and remains constant over a wide range of a...
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pn juncion diode

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Diode Characteristics  Aim: To study forward bias and reverse bias  characteristics of pn-junction diode. Instruments required: Diode 1N4007, 1k resistor, ammeter ,voltmeter. Theory: forward bias: When the p-n junction diode is in forward bias, the p-type is connected to the positive terminal of the external voltage, while the n-type is connected to the negative terminal. The potential barrier is reduced when the diode is placed in this fashion. When the voltage is 0.7 V for silicon diodes and 0.3 V for germanium diodes, the potential barriers fall, and current flows. The current grows slowly while the diode is under forward bias, and the curve formed is non-linear as the voltage supplied to the diode overcomes the potential barrier. Once the diode has crossed the potential barrier, it functions normally, and the curve rises quickly as the external voltage rises, yielding a linear curve. circuit Diagram: forward bias:
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