The main use of zener diode lies in the fact that the voltage across a Zener diode remains constant for a larger change in current. By studying these concepts, you will be able to explain Zener diode as a voltage regulator in a better way and solve exercise questions. Khan Academy is a … Hence, it acts as a voltage regulator. Determine the maximum supply voltage that may develop, for example a 12 V level, also ensuring that the minimum supply voltage is always = 1.5 V + Vz (the zener voltage rating). The Figure shows the fuction of zener diode as voltage regulator.The diode is selected in such a way that its breakdown voltage is equal to the desired output voltage. Figure 2 shows the current versus voltage curve for a Zener diode. Materials required: Battery; Rheostat; Small resistance (200 Ω) Milliammeter; Voltmeter; Key; Zener diode; Real Lab Procedure: Connections are made as shown in the circuit diagram. Refer to the voltage reference circuit to set the resistance R 1. Subsequently, a P-N junction silicon semiconductor is used to make Zener diode regulator instead of any ordinary junction diode. Hence, it acts as a voltage regulator. This is how zener diode is used as voltage regulator. Ans. Minimum reverse current is required for voltage regulation to keep diode in the breakdown region. How Zener Diode Act as a Voltage Regulator? Our mission is to provide a free, world-class education to anyone, anywhere. In this video, let's explore how a Zener diode can be used to regulate voltage. Simulator. Observe the nearly constant voltage in the breakdown region. A Zener diode working in the breakdown region can act as voltage regulator. Additionally, the voltage drop across the diode remains constant over a wide range of voltages, a feature that makes Zener diodes suitable for use in voltage regulation. 33 6.34 12.9 34 6.35 14.7 35 6.36 19.7 36 6.367 20.7 On plotting V vs I graph, we get the following: 3. Feedback. The circuit is wired up as shown in the figure. Zener Diode. 2. Let us say if Zener voltage of 5 V is used then, the voltage becomes constant at 5 V, and it does not change. Its property of breakdown voltage which we have discussed earlier plays a key role in voltage regulation. Indem die Zenerdiode einen kleinen Strom von einer Spannungsquelle über einen geeigneten Strombegrenzungswiderstand (RS) durch die Diode leitet, leitet sie genügend Strom, um einen Spannungsabfall von Voutaufrechtzuerhalten. It is a system wherein a constant voltage level is maintained either using positive feedback or negative feedback. This circuit provides safety for the equipment connected at the terminals. Your email address will not be published. Viva Voce. The output voltage of regulator system is fixed as the zener knee voltage of the zener diode and can be used in power devices requiring a fixed voltage of firm value. Thus we will connect the zener diode parallel to the load such that the applied voltage will reverse bias it. It is connected to the positive terminal of the d.c. The reason behind this is, an ordinary diode may get damaged if you apply a voltage greater than its breakdown voltage in reverse bias. The main use of Zener diode lies in the fact that the voltage across a Zener diode remains constant for a larger change in current. (ii)Explain with the help of a circuit diagram, the use of a Zener diode as a voltage regulator. when voltage equal to or greater than the breakdown voltage(3.6V) is applied across the Zener Diode in reverse direction the Zener Breakdown occurs and the output voltage of the Zener Diode becomes fixed at 3.6V. 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. Due to this feature, it is used as a voltage regulator in d.c. circuit. (Actually, to be certain the zener diode could handle the power, I placed two 12 volt zeners in parallel. Here is a link to step by step physics experiment of Zener diode as a voltage regulator and how its made. Zener diode and Zener diode as voltage regulator. Zener Diode as DC voltage regulator. When the Zener diode is given reverse bias feedback, there is a small leakage current until it attains the breakdown voltage or a constant voltage. Simulator. Class 12 Physics Semiconductor Electronics: Special purpose p-n junction diode: Special purpose p-n junction diode. Due to this feature, it is used as a voltage regulator in d.c. circuit. The Zener diode specially made to have a reverse voltage breakdown at a specific voltage. Zener Diode. Furthermore, choosing a Zener diode becomes easy as the required output voltage and the input voltage is known from the beginning. Zener diode is connected parallel to the load to make it reverse bias and once the Zener diode exceeds knee voltage, the voltage across the load will become constant. This is a circuit diagram of a Zener diode used as a voltage regulator. Similarly, the current through the diode decreases when the voltage across the diode tends to decrease. Let us say if Zener voltage of 5 V is used then, the voltage becomes constant at 5 V, and it does not change. regulation is to be made. When the input voltage is less than the breakdown voltage (V z), very small current flows through the diode and the whole input appears across the output terminals. This voltage is called zener voltage or breakdown voltage (Vz). The reverse characteristic is obtained by taking reverse voltage along – ve … This zener diode voltage regulator circuit uses a Zener diode to establish a reference voltage. Following is the link explaining the difference between Zener breakdown and Avalanche breakdown: The circuit diagram of a voltage regulator using a Zener diode is shown: Current through the diode increases when the voltage across the diode tends to increase which results in the voltage drop across the resistor. The zener diode is designed to operate in the reverse break down region and has a predetermined reverse break down voltage V z. The normal AC voltage, Vp = 220V(rms) and can vary +10% during charging. Ans. ... Zener diode voltage regulator . you are here->home->Physics->Class 12->Zener Diode. Zener Diode checking. By controlling the doping level, the breakdown region can be set during the manufacturing of the diode. To have a detailed understanding of Zener diode and its working, you should also read up on the related concepts. In the reverse bias condition the Zener diode is an open circuit and only a small leakage current is flowing as shown on the exaggerated plot. Zener diode as a voltage regulator: A Zener diode working in the breakdown region can serve as a voltage regulator. When connected in reverse bias in series with a current limiting resistor, the voltage across the zener diode remains constant as long as a certain minimum current flows through it. Here, the output voltage is balanced even if there is fluctuation in voltage supply. It is a special purpose diode, named after the inventor C. Zener; It is designed to operate under reverse bias in the breakdown region ; The symbol for Zener diode is . However, this forward flow of current can be reversed if the voltage surpasses a specific value which is known as the breakdown or Zener voltage. Nov 25, 2020 - Zener diode as a voltage regulator - Semiconductor Electronics Class 12 Video | EduRev is made by best teachers of Class 12. 3 Zener diode applications. This is how zener diode is used as voltage regulator. 6 Result The breakdown potential, also called the zener potential i.e V z ≈ 6.30V. After it attains a voltage VZ, there is unrestricted current flow in the system. This voltage at which seamless current flow begins is known as the breakdown voltage. Zener Diodes have a sharp reverse breakdown voltage and breakdown voltage will be constant for a wide rang of currents. You can even download our Vedantu app and access every related study material. We do not use ordinary junction diode because the low power rating diode can get damaged when we apply reverse bias above its breakdown voltage. However, this forward flow of current can be reversed if the voltage surpasses a specific value which is known as the breakdown or Zener voltage. It maintains a constant output voltage even when input voltage V i or load current I L varies. There is a series resistor connected to the circuit in order to limit the current into the diode. Read more to learn about the Zener diode as a voltage regulator, uses of a Zener diode, and how it is used as a voltage regulator with BYJU’S engaging videos. The experiment shows that in both conditions, it acts as a voltage regulator as it allows current to flow without showing any fluctuation in output voltage. 5. Zener Diode as a voltage regulator. As Voltage Regulator 12. It works in such a way the reverse-biased can also work in breakdown conditions. For example, if you happen to pass a 6V reverse voltage through a diode of 3V, then the measure of voltage across the diode will be 3V only. Funded by MeitY (Ministry of Electronics & Information Technology) English हिंदी മലയാളം मराठी . The Zener diode acts as a conventional diode when it is connected in the forward direction. Zener diode is specifically designed for this purpose. In this video, let's explore how a Zener diode can be used to regulate voltage. Zener Diodes are widely used as Shunt Voltage Regulators to regulate voltage across small loads. Pro Lite, Vedantu For example, we want that the voltage across a load in our circuit does not exceed, let’s say, 12 volts. The voltage regulator is used for two main reasons, and they are: Voltage regulators are used in computers, power generators, alternators to control the output of the plant. Zener diode is used as Shunt voltage regulator for regulating voltage across small loads. The semiconducting silicon material used in the zener diode as voltage regulator experiment helps it function in the forward as well as reverse voltages without breakdown. pn junction and zener diode 12 class project.ppt 1. in DEPARTMENT OF PHYICS MOTHER TERESA SR. SEC. We are going use it's reverse breakdown characteristics. Zener Diode as a Voltage Regulator In Zener diode, there is a conventional current flow from anode to cathode. The DC output voltage remains constant when the input varies within the limits as the voltage regulator is used. Learn the concepts of Class 12 Physics Semiconductor Electronics: Materials, Devices and Simple Circuits with Videos and Stories. The zener diode thus acts as a simple voltage regulator. 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. Fig 2:Zener diode characteristic curve The forward bias region of a Zener diode is identical to that of a regular diode. The image depicts a current versus voltage graph. When connected in parallel with a variable voltage source so that it is reverse biased, a Zener diode conducts when the voltage reaches the diode's reverse breakdown voltage. Pro Lite, Vedantu However, the Zener Diode or Breakdown Diode, as they are sometimes referred too, are basically the same as the standard PN junction diode but they are specially designed to have a low and specified Reverse Breakdown Voltage which takes advantage of any reverse voltage applied to it. Resources. Here, the voltage drop across the resistor is very less, and the output voltage results normally. Hence, VZ = VL. A Zener diode can limit the voltage across it, making it a voltage regulator! Zener diode. Zener diode is used as a Shunt voltage regulator for regulating voltage across small loads. Video. A Zener diode can limit the voltage across it, making it a voltage regulator! The unregulated voltage is connected through a potential divider arrangement using the rheostat. By designing the regulator here means to find the values of VZ and R. Since the load voltage is to be maintained at 12 V, we will use a zener diode of zener voltage 12 V i.e., The voltage across R is to remain constant at 16 − 12 = 4 V as the load current changes from 0 to 200 mA. (i)Zener diode is used as voltage regulator. Due to this feature, it is used as a voltage regulator in d.c. circuit. Why is Zener Diode Used as a Voltage Regulator? However, when the reverse voltages are applied, or reverse feedback is provided, a tiny leakage current is observed between the zener voltage and 0V. Zener diode is used as Shunt voltage regulator for regulating voltage across small loads. Video. The zener diode thus acts as a simple voltage regulator. We have discussed the application of Zener diode as voltage regulator and now we will discuss the other two points. The voltage difference between the input voltage V S and V Z will be dropped across the resistance R. What is the Experiment to Study Zener Diodes as a Voltage Regulator? When the breakdown occurs in Rectifier as well as Zener diode, it is known as Zener breakdown. 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. Theory. Chapter: 11th 12th std standard Class Physics sciense Higher secondary school College Notes | Study Material, Lecturing Notes, Assignment, Reference, Wiki description explanation, brief detail | Posted On : 14.03.2016 05:16 am . Ans. When the minimum input voltage and the maximum load current is applied, the Zener diode current should always be minimum. The action of the circuit can be explained as given below: Load current varies, the input voltage is constant: Let us consider that the load current increases. In a DC circuit, Zener diode can be used as a voltage regulator or to provide voltage reference. A 5 V stabilized power supply is required to be produced from a 12 V DC power supply input source. 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