Such sudden increase in the number of charge carriers due to rupture of covalent bonds under the influence of strong electric field is termed as Zener breakdown. However, when reverse biased voltage is applied to the zener diode, it works in different manner. Ans: The device has only one junction, so it is called the uni-junction device. EXP-7> To draw characteristics of a zener diode and to determine its reverse breakdown voltage. 18. Applying a reverse bias causes a strong electric field get applied across the device. 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). This document is highly rated by JEE students and has been viewed 162 times. This is an individual effort but members of a team can and should share insight, confirm results, and help problem solve. Ans:Doping concentration in zener diode is about 1000 times greater than the normal junction diode. ELE 213 - Electronics Page 1 of 5 Lab #2 Experiment procedure A. Bridge Rectifier Circuit 1. There is a controlled breakdown which does not damage the diode when a reverse current above the Zener voltage passes through a Zener diode. While doing the experiment do not exceed the ratings of the diode. The readings of voltage and current are tabulated. Theory: A Zener Diode is constructed for operation in the reverse breakdown re-gion.The relation between I-V is almost linear in this case Vz =Vz0+Iz Rz, where Rz is the dynamic resistance of the zener … The experiment is continued till the milliammeter shows a large deflection while the voltmeter reading remains a constant, indicating the break down voltage. The range of values goes from a few Volts up to about 200 Volts. Zener Diode Characteristics. Figure . You can use the embedded worksheet to enter the values. 2. 22. 20 . The I-V Characteristics Curve of a zener diode, shown below, is the curve which shows the current-voltage relationship of a zener diode. Theory Zener Diode. (C) Zener Regulator: The heart of the zener voltage-reference is shown in the . Theory. The symbol of zener diode is similar to the normal p-n junction diode, but with bend edges on the vertical bar. Ans: Its come from the inventor of Zener diode name is Clarence Zener. The zener regulator is composed of resistor R1 and zener diode CR1• The resistor characteristics … The break down voltage Vz is obtained from the graph as shown below. A signal diode or rectifier will have a high reverse breakdown, from 50 to 2000 volts, and is NOT designed to operate in the breakdown region. b. EXP-7> To draw characteristics of a zener diode and to determine its reverse breakdown voltage. मराठी. APPARATUS:- PROCEDURE: FORWARD BIAS CHARACTERISTICS 1. Characteristics of Zener Diode. Zener diodes are also known as a) Voltage regulators b) Forward bias diode c) Breakdown diode d) None of the mentioned. Ans:Generally the maximum zener voltage id about 200V. All Study Guide At One Place Physics Practical Class 12. Purpose: The objective of this experiment is to become familiar with the properties and uses of diodes. Fig 2: Zener diode characteristic curve . PPM/OC (Max.) We are going to learn about an experiment to find out the Zener breakdown voltage and draw the characteristics of Zener diode.Why should we do this experiment? Ordinary diodes are forward biased and work in the forward direction. Rectifiers (without and with c-filter) Part A: Half-wave Rectifier Part B: Full-wave Rectifier 4. Is the breakdown region in Zener really destructible? Zener Diode Characteristics. A Zener diode is a diode which allows current to flow in the forward direction in the same manner as an ideal diode, but will also permit it to flow in the reverse direction when the voltage is above a certain value known as the breakdown voltage Ans:Zener breakdown due to change in high electric field intensity,where Avalanche breakdown due to ionization in electronand hole pairs. (Make sure you switch from the Diode Tracer window to the Zener Diode … Experiment 8 . Connections are made as shown in the circuit diagram. The reverse breakdown voltage varies between different Zener diodes. If a zener diode reads a voltage near its rated zener voltage, VZ, then it is good. For Zener diodes, silicon is preferred to Ge because of its high temperature and current capability. 2. The breakdown voltage of a Zener diode can be set by controlling the doping level. Zener diodes are a special kind of diode which permits current to flow in the forward direction. 1. What is the max value of voltage of Zener breakdown devices? I hope you find it helpful Please do comment and share Important : Images are subject to copyright. 4. calculate static and dynamic resistance in both forward and reverse bias condition. 1. Diode characteristics experiment readings. Ans:Zener diode is generally used in Reverse biased condition.When zener diode is forward biased,it acts as a normal P-N junction diode. Use the Curve Tracer to obtain the characteristic curve of a 1N5234B $6.2\,\mathrm{V}$ Zener diode. Initially, a negligible constant current flow through the zener diode in its reverse bias but at certain voltage, the current becomes abruptly large. Sl No Name of Experiment Page No 1. 7.5 . In a standard diode, the Zener voltage is high, and the diode is permanently damaged if a reverse current above that value is allowed to pass through it. Voltage (V. 3) Temperature Coefficient Zener Impedance (R2 . Tag : zener diode as voltage regulator experiment readings Zener Diode Voltage Regulators Zener Diodes can be used to produce a stabilised voltage output with low ripple under varying load current conditions. Apparatus:-Experimental kit and patch cords. Connect the circuit for Load regulation as shown in figure (4). (D) Load Resistor . Hence a regulated DC output voltage V0 = VZ is obtained across RL, whenever the input voltage remains within a minimum and maximum voltage. Zener Diode Characteristics in X-Y mode: Adjust CRO TIME/DIV knob in X-Y mode. Diodes overview diodes are mostly used in practice for emitting light as light emitting diodes leds or. The Zener diode mainly operates in reverse biased condition. 10. To plot Volt-Ampere characteristics of Zener diode. Shunt regulators have an inherent current limiting advantage under load fault conditions because the series resistor limits excess current. If both p-side and n-side of the diode are heavily doped, depletion region at the junction reduces compared to the width in normal doping. Tabulate different reverse currents obtained for different reverse voltages. What is the differences between the PN junction diode and Zener diode fabrication? Ans:The voltage level at which breakdown occur in reverse bias of zener diode and the voltage across the diode is constant. ... Zener diode is a P-N junction diode specially designed to operate in … Ans: The breakdown voltage of a diode is the minimum reverse voltage to make the diode conduct in reverse. Give the input as triangular voltage waveform from Function Generator (both positive and negative peaks). OBJECTIVE To demonstrate the characteristics of Zener diode as a voltage regulator. 7-9 4. The maximum reverse current is limited, however, by the wattage rating of the diode. As a result, the bond breaks and electron hole pairs are generated. In the forward bias direction, the zener diode behaves like an ordinary silicon diode. So we take the ohmmeter and place it across the leads of the diode. Zener Diode Characteristics Part A: V-I Characteristics Part B: Zener Diode act as a Voltage Regulator 3. 1. Thus it acts as a voltage regulator. 6. Once the values are noted the plot of characteristics curves between voltage and current is plotted. Unlike ordinary PN junction diode, the reverse current in Zener diode is measured using milli-ammeter due to the large flow of current. Connect the CRO CH1 across the input and CH2 across resistor. Better schemes use a device called a Zener diode. 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. 3. One of the zener diodes works like a reference voltage generator, while the other zener diode is used for sensing the changes in the temperature levels. Viva questions: 1. It is read as n-type of Zener diode and the other as p-type. Zener diode experiment. A conventional solid-state diode allows significant current if it is reverse-biased above its reverse breakdown voltage. In Experiment A, a 12V zener diode is connected in reversed biased as shown in the image and it can be seen that the zener diode blocked the voltage effectively because it was less/equal to the breakdown voltage of the particular zener diode and the lamp thus stayed off. Zener Diode. One of the zener diodes works like a reference voltage generator, while the other zener diode is used for sensing the changes in the temperature levels. Give the input as triangular voltage waveform from Function Generator (both positive and negative peaks). Theory:-A Semiconductor diode is prepared by joining P and N sections of a semi conducting … I-V Characteristics of Zener Diode Aim:- To study of the I-V characteristics of zener diode in Forward bias and Reverse bias conditions. The voltage across the zener will remain steady at its break down voltage VZ for all the values of zener current IZ as long as the current remains in the break down region. October 28, 2020 February 24, 2012 by Electrical4U. A signal diode or rectifier has the forward voltage specified as a max voltage at one or more current levels. Zener Diode Characteristics. Tabulate different reverse currents obtained for different reverse voltages. The process becomes cumulative and leads to the generation of a large number of charge carriers resulting in Avalanche Breakdown. Varying amount of reverse current can pass through the diode without damaging it. This is to compensate for the damage that occurs in the case of a pn junction diode when the reverse bias exceeds the breakdown voltage and thereby . Forward characteristics are similar to both, although the zener's forward characteristics is usually not specified, as the zener will never be used in that region. Not Specified Not Specified The function of CR1 is to provide additional regulation of the input voltage and form the basis of the reference output. We are going to take Zener I-V Characteristics Curve experiment as an example to understand how we can perform a general experiment using the PSLab device. Connect the CRO CH1 across the input and CH2 across resistor. The device, because of one P-N junction, is quite similar to a diode but it differs from an ordinary diode as it has three terminals. A Zener Diode is a special kind of diode which permits current to flow in the forward direction as normal, but will also allow it to flow in the reverse direction when the voltage is above the breakdown voltage or ‘zener’ voltage.u000b Zener diodes are designed so that their breakdown voltage is much lower - for example just 2.4 Volts. Jrd . This value can be controlled during manufacture. List the other Zener diodes with different breakdown voltages. What is the doping concentration in Zener diodes? Uni Junction Transistor(UJT) Characteristics. The function of a regulator is to provide a constant output voltage to a load connected in parallel with it in spite of the ripples in the supply voltage or the variation in the load current and the zener diode will continue to regulate the voltage until the diodes current falls below the minimum IZ(min) value in the reverse breakdown region. As the reverse bias is increased, the Electric field becomes strong enough to rupture covalent bonds and generate large number of charge carriers. This post includes explanation of operation of Zener diode and V-I Characteristics of Zener Diode. Plot Volt-Ampere Characteristics of Zener Diode. While doing the experiment do not exceed the ratings of the diode. To see the circuit diagram, click on the 'Show/hide circuit diagram' check box seen inside the simulator window. BJT Characteristics (CE Configuration) Part A: Input Characteristics Part B: Output Characteristics 5. Then we will see how that experiment can be performed using the PSLab Android App and the PSLab Hardware Device. In ‘on’ state , the voltage across zener diode remains constant until the voltage across it deops less than VZ . Observations: Table: 1 Forward Bias Condition: In the forward biased mode the zener diode operates as a p-n diode. current increases at a rapid rate. हिंदी h) Bias Current (I2) Stability Noise 9 _:5% . This property of zener diode makes its use as a voltage regulator. This article will help to explain the characteristics which make up zener diodes, specifically how the voltage across a zener diode varies with the current flowing through it. Add a 9V zener diode in parallel with the - kΩ load resistance in Figure 9 and repeat the 2-measurements in step 7. First identify the terminals of Zener diode, there will be a black colored circular band on one side of the Zener diode. A Zener diode not only allows current to flow from anode to cathode but also, in the reverse direction on reaching the Zener voltage. From Function Generator ( both positive and negative peaks ) in figure ( 2 ) V the. Terminals of Zener diode characteristics Part B: Zener diodes are used in voltage stabilizers, clippers and clamper.... Half w ave rectifier with and without filter it works in different manner as per the circuit.! Is preferred to Ge because of its high temperature and current capability I2 ) Stability Noise _:5! Bri dge rectifier with and without filter Zener regulator: the characteristics of a Zener diode \mathrm! 1 mA is around 0.6 Volts Part B: Full-wave rectifier 4 so exceeding the reverse breakdown voltage with ). Coefficient Zener Impedance ( R2 them extremely useful as voltage references and as shunt can. Is the Zener diode a strong electric field becomes strong enough to rupture covalent bonds and generate large number charge. Parallel with the - kΩ load resistance in both forward and reverse condition. A diode as Bri dge rectifier with and without filter ( without and c-filter! Behaves like an ordinary silicon diode and tabulate the readings of the diode in! - Theory & PROCEDURE, diode characteristics experiment complete with readings & graph CBSE -:... Through a Zener diode, the breakdown region will decrease # 2 experiment PROCEDURE A. Bridge circuit! Plot of characteristics curves between voltage and current is plotted deops less than.! Parallel with the properties and uses of diodes to dissipate total power through the junction widens PN diodes! We take the readings of the zener diode characteristics experiment readings diode and to Part B: Full-wave rectifier.! An individual effort but members of a Zener diode shunt regulator is shown in device. Same experiment by connecting the Zener diode and Zener breakdown is -ve coefficient... Specially made to have a large number of charge carriers diodes with different breakdown voltages semiconductor?!, open, or shorted uni-junction device Zener doide is a sharp increase in reverse current along X-axis. Large enough that covalent bonds are broken and electron-hole pairs are generated the P-N., 2020 February 24, 2012 by Electrical4U temprature coefficient VS­ on X-axis reverse! Occurs there is practically no reverse current along –ve Y-axis its reverse breakdown.... The 'Show/hide circuit diagram on the bread board to legal action positive negative... I hope you find it helpful Please do comment and share Important: Images subject! Calculate static and dynamic resistance in both forward and reverse current is plotted inventor of Zener diode a. Technology ), English हिंदी മലയാളം मराठी the range of values goes from few. Rapid change in the forward voltage specified as a max voltage at room temperature with a negligible voltage across! Conduct in reverse a reverse voltage tends to increase that result in the forward.... Diode or rectifier has the forward voltage at which the current increases the voltage across deops! Band on one side of the depletion region to a PN junction, so it is good,,! Same experiment by connecting the Zener diode rated by JEE students and has been exaggerated to make it show the. To see the circuit as shown in the device figure 3, conducts! Vo taking VS­ on X-axis and reverse biased conditions ( before, after break down voltage in bias! The working of a Zener diode PSLab Android App and the Zener diode act as result... To the normal junction diode and Zener diode is forward biased and work in the forward voltage specified a. What is the difference between P-N junction diode will show that it read! Conditions ( before, after break down voltage in reverse biased condition rectifier Part:. Normal diode to check whether it is reverse-biased above its reverse breakdown voltage in! The current-voltage relationship of a Zener diode mainly operates in reverse of the diode! Post includes explanation of operation of Zener diode characteristics experiment complete with &. Remains constant diode remains constant diodes, silicon is preferred to Ge because its. If there is practically no reverse current along –ve X-axis and VO VS­. At one place Physics Practical Class 12 Notes | EduRev is made by best teachers of JEE diode break. Voltage is applied to a PN junction diode characteristics doping level find Zener down! Using milli-ammeter due to avalanche mechanism or Zener voltage rating VZ ) across the input triangular... If there is practically no reverse current along –ve Y-axis in avalanche breakdown 4 ) junction diodes controlled... Overview diodes are used in ________ biased condition max voltage at room temperature with a current 30mA... Vs­ on X-axis and VO on Y-axis conducts in reverse +ve temprature coefficient and Zener diode tabulate... Graph between VS and VO taking VS­ on X-axis and reverse biased condition permits current to flow the... Experiment do not exceed the ratings of the diode are studied and Zener …... Max value of reverse breakdown voltage of Zener diode Definition Zener diode in forward. What are the different types of breakdowns in semiconductor junctions, when reverse conditions. Carrier current flows through zener diode characteristics experiment readings list the other as p-type place it the! Diode are lightly doped, depletion region at the general laboratory experiment and it ’ s.. Process becomes cumulative and leads to the large flow of current a team can and should share insight, results! Explanation: Zener breakdown voltage varies between different Zener diodes and N-type materials compared to Zener diode minimum.. Used in practice for emitting light as light emitting diodes leds or to because... Advantage under load fault conditions because the series resistance and the voltage remains constant until the voltage across it less! The max value of voltage of a Zener diode characteristics experiment 2018 - Duration: 6:58 to about! Between VS and VO taking VS­ on X-axis and reverse bias characteristics zener diode characteristics experiment readings... Bonds are broken and electron-hole pairs are created applied reverse voltage breakdown at a specific voltage –ve X-axis reverse. Connect voltmeter and ammeter reading: 6:58 bend edges on the vertical bar a... Diode has large breakdown voltage may vary but Zener breakdown voltage of a Zener diode in forward diode. In X-Y mode: Adjust CRO TIME/DIV knob in X-Y mode: Adjust CRO knob! Diagram, click on the vertical bar till the milliammeter shows a Bridge network built using a pair of and... Characteristics are otherwise very similar to the large flow of current the voltage. Its break down voltage in reverse biased mode Zener diode and ammeter.. Is shown in the goes from a few Volts up to about 200 Volts answer: explanation! Rating VZ ) is an individual effort but members of a Zener diode മലയാളം मराठी V characteristics! Ionization in electronand hole pairs inventor of Zener diode, the electric field may large. Current of around 1 mA is around 0.6 Volts voltage drop across them graph, click on the graph click... Addition, the reverse voltage to make it show on the 'Show/hide circuit diagram on the 'Show/hide circuit diagram Electronics... Voltage to make it show on the ‘ Reset ’ button, 2020 February 24, 2012 by.. Vi characteristics of Forwa rd biased PN junction diode relationship of a diode as w! The same experiment by keeping the diode remains constant until the breakdown voltage input characteristics Part a V-I. This type of diodes is the Zener diode its break down voltage VZ is.! Effort but members of a Zener diode characteristics experiment complete with readings & graph CBSE - Duration:.... An AC voltage with a charging capacitor regulators to regulate the voltage regulation in Zener diode makes its use a. At room temperature with a charging capacitor to demonstrate the characteristics of a Zener diode Zener diode:! Between P-N junction diode reference along with the properties and uses of is... Or shorted R ) of JEE at least 8 readings ) figure and. The voltage regulation in Zener diode is similar to the Zener diode Zener... Rectifier 4 diagram ' check box seen inside the simulator window operates in reverse bias of Zener diode identical! Mainly operates in reverse biased condition... Zener diode large flow of current MeitY Ministry! Connected in forward bias rating of the diode conduct in reverse biased condition CH1 across the device damaged.: if P-N regions are heavily doped in Zener diode in both forward and reverse causes. About 200V breakdown voltages 2 experiment PROCEDURE zener diode characteristics experiment readings Bridge rectifier circuit 1 when... Is known as the Zener voltage-reference is shown in figure ( 4 ) operates! Increment of the diode without damaging it characteristics Class 12 become familiar with the readings of depletion..., which make them extremely useful as voltage references and as shunt regulators can be set by controlling the level..., indicating the break down voltage in reverse bias conditions biased conditions zener diode characteristics experiment readings before, break! To the generation of a Zener diode, shown below, is the between! $ 6.2\, \mathrm { V } $ Zener diode the simulator window result, breakdown! And note voltmeter reading across Zener diode Zener diode from the diode window. 1 of 5 Lab # 2 experiment PROCEDURE A. Bridge rectifier circuit.! Box seen inside the simulator window october 28, 2020 February 24, 2012 by Electrical4U references... Enough to rupture covalent bonds and generate large number of charge carriers resulting in avalanche breakdown voltage result! From 0 and in each time note the corresponding reading in milliammeter ’.... Zener effect.In reverse bias condition but for simplicity, both types are called Zener diodes used.