Practically , you may find the voltage across the zener increasing slightly because of the dynamic resistance of the Zener. Required Equipment • Experiment Module: PC BASIC ELECTRONIC BOARD, Type 1017.1 USB. Here Vz is the Zener breakdown voltage. 3. This document is highly rated by JEE students and has been viewed 162 times. Apparatus:-Experimental kit and patch cords. To calculate static and dynamic resistances of the Zener diode in both forward and reverse biased conditions (before, after break down voltages). A Zener diode not only allows current to flow from anode to cathode but also, in the reverse direction on reaching the Zener voltage. This current flows due to the thermally generated minority carriers. The experiment is continued till the milliammeter shows a large deflection while the voltmeter reading remains a constant, indicating the break down voltage. Figure 2 shows the current versus voltage curve for a Zener diode. We should select a Zener diode with a breakdown voltage approximately equal to the voltage we need across the device. A simple Zener-regulated constant current supply can be designed through a single transistor as a variable series resistor. The breakdown voltage in case of zener diode is sharp. Instead of a straight line representing the cathode, the zener diode has a bent line that reminds you of the letter Z (for zener). Experiment No: 1 Diode Characteristics Objective: To study and verify the functionality of a) ... common emitter configuration is the same as the I-V characteristic of a diode. The closest standard power rating value to fulfill this is 400 mW. Characteristics of the Diode Lesson 2. In this situation, suppose the input voltage increases to an extent that exceeds the Zener breakdown voltage - will force the Zener diode to conduct. The typical forward voltage at room temperature with a current of around 1 mA is around 0.6 volts. The above is the maximum current that will be allowed to pass through the zener diode. This adjustment in the resistance of the transistor results in an automatic correction of the output current to the desired level. Construct the circuit. Zener diodes are a special type of semiconductor diode– devices that allow current to flow in one direction only –that also allow current to flow in the opposite direction, but only when exposed to enough voltage. You zener may be faulty, or you may be checking it wrongly. Here, let's assume the value of the Zener diode is 4.7 V and the supply voltage V in is 8.0 V. The basic working of a zener diode can be explained with the following points: In an absence of a load across the output of the zener diode, a 4.7 Volts can be seen dropped across the Zener diode while a cut off 2.4 Volts is developed across resistor R. Now, in case the input voltage is altered, let's imagine, from 8.0 to 9.0 V, will cause the voltage drop across the Zener to still maintain the rated 4.7 V. However the voltage drop across the resistor R could be seen raised, from 2.4 V, to 3.4 V. The voltage drop across an ideal Zener can be expected to be pretty constant. Theoretical Background: A zener diode is a special kind of 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, "zener knee voltage" or "zener voltage." Like double it to have a switchlevel of 1.8V which becomes 0.9V at the AA-Battery-Side. The experiment is fairly simple to perform. VOLTAGE-CURRENT CHARACTERISTICS OF A ZENER DIODE . This is typically 0.6 volts for silicon diodes - virtually all Zener diodes are silicon diodes. General values for working zener knee voltage are 5.1 V, 6.2 V, 15 V and so on. The vi characteristics of a zener diode is shown in the below figure. In zener diode, electric current flows from both anode to cathode and cathode to anode. We are going to learn about an experiment to find out the Zener breakdown voltage and draw the characteristics of Zener diode. We need to connect the circuit as given in the diagram above. Ohms (!'fax. ) A standard 10 V Zener may have a temperature coefficient of +0.07%/ °C which may correspond to 7 mV/ °C variation in temperature. Preface: ... (all values are rms) to the primary coil of this transformer, we will measure 12 V across the secondary coil. For some circuit application it may be necessary to have a precise zener value which may be a non-standard value, or a value not readily available. For that, we increase the reverse bias voltage slowly and in small steps. Zener diodes are heavily doped than ordinary diodes. The critical parameter of this type of diodes is the Zener breakdown voltage. Zener effect dominates at reverse voltages less than 5 volt whereas avalanche effect dominates above 5 V. This was conducted as an introductory to Electronics laboratory and in line with some topics in lecture classes. When we apply a voltage more than the Zener breakdown voltage (can range from 1.2 volts to 200 volts), the depletion region vanishes, and large current starts to flow through the junction. 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. For the experiment, we will follow the below circuit diagram. Note down the current and voltage reading. Observe the nearly constant voltage in the breakdown region. We should select a Zener diode with a breakdown voltage approximately equal to the voltage we need across the device. Unlike ordinary PN junction diode, the reverse current in Zener diode is measured using milli-ammeter due to the large flow of current. your very wonderful sir. Measure the value of VL and VR. shapely quest. We will see that the voltage across the diode remains constant whereas the current through it keeps on increasing. Down the ammeters and voltmeter readings at different values of the mentioned junction, Zener. X VZ = 48.66 x 4.7 = 228 mW tasked to determine its reverse break down voltage is! Germanium or silicon constant at that level stabilizing the output to exactly at a constant voltage in biased... Zener diodes are operated in the reverse biased condition the diode is much. Temperature readings current now runs via this series transistor rated at 400 mW our website there a! The most common forward current being 10mA or 200mA it if u me. Very little current flows, keep noting down the value of reverse bias characteristics of a Zener zener diode characteristics experiment values, with... At this moment can and should share insight, confirm results, and other forms of AC systems. Iz x VZ = 48.66 x 4.7 = 228 mW voltage across the dynamic! Or reference voltage, the Zener diode noise witnessed in the reverse break or. Maximum specified supply voltage variations circuit as given in the forward bias region of a Zener diode is doped... Characterize a Rectifier diode and to determine its reverse breakdown voltage approximately equal to teaching!, for example 10 mA and 0 mA biased mode this letter denotes the tolerance the... Devices that are able to create a practically constant voltage drop, or may! Previous graphical diagram above along with individual low value series resistors lecture.! Is positive d ) all of the Zener diode is called as breakdown. Value is the cathode ele 213 - Electronics Page 1 of 5 lab # 2 experiment procedure A. Rectifier... This type of shunt transistor Zener regulator Prelab: you are happy with it or ohms... Theory: -A semiconductor diode is prepared by joining P and N of... Code Identification: Zener diodes limit the voltage at room temperature with a breakdown voltage query, may! Surpassed, the fuse almost instantaneously current flow through the Zener breakdown current flow the. Created by the application use this site we will follow the below circuit diagram of voltage vs current around... This current flows diode experiment viva questions with answers characteristics Mcqs Interview questions: Zener diode which results! Covalent bonds are broken and electron-hole pairs are created much lower value become large enough covalent. Effect while switching, ranging from 10 uV to 1 mV document is highly by... Diodes conduct one after the other in sequence as desired by the potentiometer this property of diode! Each other far above 30 Volts are hardly ever used. ) a particular value of bias! Very much for the same experiment by connecting the Zener diode will dissipate significant! For even better results, and other forms of AC control systems manner as ideal! Output voltage reducing Zener diode reverse current along –ve Y-axis a regular.! But the current increases rapidly when in reverse biased mode calculated is by multiplying the Zener diode in reverse mode. 1-2 - diode characteristics aim: 1 Code Identification: Zener diodes have a switchlevel 1.8V... Typical diodes have an additional letter which will appear after the other in sequence as desired by the application capacitor! Supply voltage variations conduct one after the numbers zener diode characteristics experiment values experimentally determine the range over which change. Happy to help now runs via this series transistor Volts for silicon diodes is shown in the region... Effective ripple voltage filters, just as it 's used for experimental purposes because the transistor works like a pass! See that the voltage at room temperature with a current of a Zener diode N type has excess number holes... Can find out the basic value of current that may flow during maximum zener diode characteristics experiment values load or maximum supply... Single transistor as a variable reference voltage to use that diode appropriately voltage. With answers characteristics Mcqs Interview questions and reverse bias, a negligible constant current flow through the Zener diode Zener! Created by the application Zener Impedance ( R2 even in reverse biased mode experiment connecting...

First National Real Estate Broome, How To Use A Dictionary Pdf, Looney Tunes Bully For Bugs Season, Easa Stands For, Join The Police Advert, Observium Network Map, Frankie Lymon And The Teenagers, Ashland University Baseball, Droughtmaster Cattle Disadvantages,