The breakdown voltage of Zener diodes will be constant for a wide range of current. When forward biased, it behaves like a normal signal diode, but when the reverse voltage is applied to it, the voltage remains constant for a wide range of currents. Zener diodes are commonly employed in applications as voltage regulators. IL            Current passing through the load resistance, The total current drawn from the source is the same as that through the series resistor, Copyright @ 2021 Under the NME ICT initiative of MHRD. The normal AC voltage, Vp = 220V(rms) and can vary +10% during charging. For a simple electronic voltage regulator using Zener diode, I use the following circuit. Beyond that current the diode can be damaged. And it is this characteristic of a zener diode that permits it to be used as a voltage regulator. In this type of regulation, input voltage is fixed and the load resistance is varying. A Zener diode is a very useful device for regulating voltage. Zener Diodes have a sharp reverse breakdown voltage and breakdown voltage will be constant for a wide rang of currents. Imax             Maximum current for Zener diode, VZ          Zener Diode standard  voltage, Vin          Input voltage(it is known) When selecting the zener diode, be sure that its maximum power rating is not exceeded. The Zener diode is often used to create a reference voltage. Avalanche and Zener Breakdown. First, take note … For example, a 5.6 V, 0.5 W zener diode has a recommended reverse current of 5 mA. The Zener conducts the least current when the load current is the highest and it conducts the most current when the load current is the lowest. Minority carriers in the depletion region gets accelerated by the reverse biased electric field. Figure. Output voltage remains the same as long as the input voltage is maintained above a minimum value. VI characteristics of Zener diode: 1.) The V-I characteristics of an ideal zener diode is shown in Figure 1–1 (a) and a simple regulator circuit based on it in Figure 1-1 (b). When you know the level of the supply voltage and you have a small load, using a Zener diode as a regulator can be a great option; however, without proper components, this circuit can be far … Comments (0) Groups (1) There are currently no comments. Then for all other combinations of input voltage and load current the Zener diode conducts the excess current thus maintaining a constant voltage across the load. A simple circuit involving Zener diode as a regulator requires a resistor of the low value connected in series with the input voltage source. It provides a better regulation over a wider range of load currents and input voltages. when Voltage across Zener diode is increased above its reverse breakdown voltage it starts conducting and reduces Voltage across it by acting short-circuited. With an ideal Zener diode, construction of a voltage regulator is easy, simply connect the diode between the unregulated voltage and ground. Social Share. Zener Diode-As Voltage Regulator 1. Zener diodes have voltage values from less than 2 volts to several hundred volts, and they can dissipate power ranging from 0.25 to 50 watts… or more. A Zener diode is manufactured for lower and exact reverse break down voltage. Zener diode voltage regulator circuit. 2) 6 volt zener diode is connected across the power source of 10 volt with series resistance 1k ohm. It is driven by a current source. A voltage regulator is a system designed to automatically maintain a constant voltage level. ; It requires only two or three components. Is = Izmin + ILmax Zener Diode as a Voltage Regulator Zener diode is a silicon semiconductor with a p-n junction that is specifically designed to work in the reverse biased condition. 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