Leo esaki invented a tunnel diode, which is also known as esaki diode on behalf of its inventor. The diodes are classified into different types based on their working principles and characteristics. The principle behind the diode is similar to a valve or a gate, which lets electricity flow only in one direction simple. To construct a zener voltage regulator and experimentally determine the range over which the zener maintains a constant output voltage. Fig 8 vary the voltage v on the power supply between 030v.
When a reverse bias is applied, a small reverse saturation current appears. To study the characteristics of the forward and reverse biased junction diodes. The lead connected to the ptype material is called the anode and the lead connected to the ntype material is the cathode. Experimently find out whether the given diode is made of germanium or silicon. For the forward characteristics of the given pn junction diode, a graph is plotted with forward voltage along x axis and forward current along y axis. A theoretical model of the diode characteristic curve is given by the equation. Because of heavy doping depletion layer width is reduced to an extremely small. Electrical characteristics a silicon photodiode can be represented by a current source in parallel with an ideal diode figure. To study and verify the functionality of a pn junction diode in forward bias b pointcontact diode in reverse bias components equipments required. Diode characteristics physics astronomy project topics.
The the temperature dependence o f the threshold current i th was investigat ed and l i characteristic. Semiconductor physics semiconductors and diodessemiconductors. Carry out the recording for both forward and reversed bias characteristics. Diode is an electronic device having conductor at their ends. Observation of characteristics of a zener diode debangshu mukherjee bs. Lab 1 diode characteristics purpose the purpose of.
These include generic diode, schotty diode, shockley diode, constantcurrent diode, zener diode, light emitting diode, photodiode, tunnel diode, varactor, vacuum tube, laser diode, pin diode, peltier diode, gunn diode, and so on. The forward current shows a sudden increase at certain forward voltage, which is known as the knee voltage. The diode will be easier to understand if we compare the diode to another two terminal device we know and love the resistor. The current i may be deduced using r v i r, converting the recorded voltage v r in the yinput into current scale. So thats the forward bias characteristics of a pn junction diode. To find cutin voltage for silicon pn junction diode.
The vi characteristics of a diode can be forward or reverse. The experiments in this laboratory exercise will provide an introduction to. Jan 02, 2019 a graph of current through vs the voltage across the device is called the characteristic of zener diode. The characteristics of a regular junction diode will show that it is designed primarily for operation in the forward direction. Diodes overview diodes are mostly used in practice for emitting light as light emitting diodes, leds or controlling voltages in various circuits. Jan, 20 the characteristics of a regular junction diode will show that it is designed primarily for operation in the forward direction. Some of the characteristics that will be investigated are the iv curve and the rectification properties. Three important characteristics of a diode are, first of all, the forward voltage drop. The figure depicted under the section forward characteristic shows that forward voltage and reverse voltage are usually plotted on the horizontal line of the graph. It conducts current linearly with increase in voltage applied across the 2 terminals. In general, the cathode of a diode is marked by a solid line on the diode. Useful mathematical relations are shown and illustrated with plots. Verify kirchhoffs voltage law kvl and kirchhoffs current law kcl using mesh and nodal analysis of the given circuit.
The graph showing the forward bias voltage and forward current is known as the forward characteristics, and that showing the reverse bias voltage and reverse current is known as the reverse characteristics. Solve each circuit with its corresponding diode equation. A graph of current through vs the voltage across the device is called the characteristic of zener diode. Diodes and diode circuits tlt8016 basic analog circuits 20052006 2 3. Reverse biasing will generally not cause current conduction until higher values of. Conclusion this experiment focuses on the investigation of. This was conducted as an introductory to electronics laboratory and in. Zener breakdown voltage should be approximately close to the desired voltage. Conclusion this experiment focuses on the investigation of the basic characteristics of a diode.
The vi characteristic of zener diode indicates that characteristic of zener diode in forward bias is same as pn junction diode. Use suitable input scales and calibrate the scale on the recording sheet. You may use either of three methods to measure the vi characteristics. Use the inequality for that diode state range of validity to find the range of circuit variable which leads to. Many types of diode are used for a wide range of applications. With the diode check function a good diode will show approximately.
The objective of this experiment is to measure the iv curve for pn junction diode and to understand the characteristics of pn junction. A diode is simply a pn junction, but its applications are extensive in electronic circuits. The ideal diode equation is a good approximation of the diode current over selected. With the diode check function a specific known voltage is applied from the meter across the diode. To study and measure the effects of forward and reverse bias on the zener diode current. Diode characteristics diode and diode circuits diodes and. Because diodes of the same type can have significantly different characteristics, use the same diode for all experiments in this lab. Calculation do a curve fitting using the diode equation. Lab 1 diode characteristics purpose the purpose of this lab is to study the characteristics of the diode. Its a high conductivity two terminal pn junction diode doped heavily about times greater than a conventional junction diode.
To study the characteristics of pn junction diode under forward bias and reverse bias condition. When the photodiode is forward biased, there is an exponential increase in the current. But due to higher doping concentration, higher current flows through the zener. You can access the data sheet from thr following site auinternalworkshopstorepdf1n4004. Diode iv characteristics the forward and reverse current voltage iv characteristics of a diode are generally compared on a single characteristic curve. Use the inequality for that diode state range of validity to find the range of circuit variable which leads to that state. Photodiode characteristics 8 iv characteristics the currentvoltage characteristic of a photodiode with no incident light is similar to a rectifying diode. Material and equipment ni elvis 1n5404 diode 1n zener diode 1n4148 diode.
To study the forward and reverse bias characteristics of diode and zener diode. Laser diode may be adversely affected by static electricity and surge current and, consequently causes breakdown of element and reduction of reliability unless the following cares are taken. Conduct the experiment for obtaining the forward bias vi characteristics of the given diode. Each diode was investigated by plotting the iv curve using a precision sourcemeasurement unit b2902a and a laptop with the corresponding quick iv measurement software installed. A semiconductor diode is prepared by joining p and n sections of a semi conducting. Diode characteristics physics kids projects, physics science fair project, pyhsical science, astrology, planets solar experiments for kids and also organics physics science ideas for cbse, icse, gcse, middleschool, elementary school for 5th, 6th, 7th, 8th, 9th and high school students. Reverse biasing will generally not cause current conduction until higher values of reverse voltage are reached.
Experiment 6, photodiode and phototransistor current. For correct voltage regulation, we need to find out precisely what voltage should be across the zener diode. To plot voltampere characteristics of silicon pn junction diode. Research the names for these parameters and values you can expect for them. Replace the procedure in experiment 3 with the following procedure 1 measure the voltage and current through a signal diode use a 1n4148 from your graymark kit these are also available in the instrument room. The experiment was conducted to explore the characteristics of a diode laser. To study and verify the functionality of a pn junction diode in forward bias b pointcontact diode in reverse. The ideal diode equation is a good approximation of. Diode characteristics 2012 summary this experiment was set up to investigate the different properties and characteristics of several different types of diode. You diodes will use the bit bucket breadboarding system to build and test several dc and ac diode circuits.
Deduce the forward working voltage of the diode vd. Under a forward bias condition, this should be about. To calculate static and dynamic resistances of the zener diode in both forward and reverse biased conditions before, after break down voltages. Lab experiment related theory available in following books. When a forward voltage is applied, current flows through it. Parametric solution of diode circuits is desirable. Forward biasing will cause a large if with a rather small value of vf. To study and measure the effects of forward and reverse bias on the zener diode. A pnjunction diode is formed when a ptype semiconductor is fused to an ntype semiconductor creating a potential barrier voltage across the diode junction the effect described in the previous tutorial is achieved without any external voltage being applied to the actual pn junction resulting in the junction being in a state of equilibrium. Experiment 1 vi characteristics of diode vi characteristics of diode aim. In the reverse, when we reverse bias the diode the depletion. V z0 is the voltage at which the straightline approximation of the iv characteristic intersects the horizontal axis. Testing a diode is quite simple, particularly if the multimeter used has a diode check function.
The forward characteristics of a diode is non linear. The curve of the zener diode will also be looked at. Ab0l is a compact, ready to use diode characteristics experiment board. The purpose of this laboratory investigation is to determine the voltage and current characteristics of several pn junction diodes including the 1n4148 signal diode, the 1n4004 rectifier diode and the 1n5231b zener diode. If you need to use your diode on another day, mark it with a piece of tape with your name and leave it in the storage cubbies in the back of the lab. To find zener break down voltage in reverse biased condition.
The polarity of the voltage source is such that the photodiode is reversed biased. Diode iv characteristics the iv graph for a nonideal diode is shown in figure 2, along with an ideal approximation to accommodate the nonzero threshold voltage. The principle behind the diode is similar to a valve or a gate, which lets electricity flow only in one direction simple english wikipedia, diode. When the positive polarity is at the anode the diode is forward biased and is conducting. If you took your data from both modes of operation and plotted it on a linear scale it would look similar to figure 2. In reverse bias, a negligible constant current flow through the zener diode but the current becomes abruptly large at certain voltage. Experiment 6, photodiode and phototransistor current measurements. We are going to learn about an experiment to find out the zener breakdown voltage and draw the characteristics of zener diode. Name quantity name quantity 1 diode by127, oa79 1one no each dc regulated power supply. Jan 02, 2019 we are going to learn about an experiment to find out the zener breakdown voltage and draw the characteristics of zener diode.