Identify the types of diodes. BACKWARD DIODE-also known as back diode, although not widely used by many, it is a form of PM-junction diode which is very similar to the tunnel diode in its operation. BARRIT DIODE-a short term of Barrier Injection Transit Time diode (BARRIT), applicable in microwave application and bears similarities to the widely used IMPATT diode.
GUNN DIODE-a PN-junction diode, a semiconductor device which has two terminals. Generally used for producing/generating microwave signals. LASER DIODE-also known as “Light Amplification Stimulated Emission Radiation”. Not the same as the LED (Light Emitting Diode) because it produces an a coherent light. Laser diodes are widely used in many application such as DVD, CD, fiber optic communications, barcodereaders, laser ponter recording, laser printing, etc. although cheaper than other types of laser generator they are expensive than LEDs. They have limited of life.
LED -stands for “Light Emitting Diode”, one of the most standard types of the diodes. Converts electrical energy to produce light energy.it undergoes electroluminescence process in which holes and electrons are recombined to and produce energy in the form of light when in forwards biased. They are widely used in applications like aviation lighting, traffic signals, camera flashes, and more.
PHOTODIODE-used for detecting light. When a light strikes a PN-junction it can create electrons and holes. Typically operated in reversed biased condition where even a small amount of light can easily detected. They can also generate electricity. In application it mostly works well with PIN diodes as photodetectors. PIN diode -characterized by its construction. It has a standard P-type and N-type regions, but between them there is an area of two regions namely intrinsic semiconductor which has no doping. The area of the intrinsic semiconductor has the effect of increasing the area of the depletion region which can be useful for switching applications as well as for use in photodiodes, etc.
PN JUNCTION-The most fundamental and simplest electronic device that when one side of anintrinsic semiconductor is doped with an acceptor ,and one side is made up of p-type by doping with the n-type material a p-n junction diode is formed. It has two terminals. These diodes can come as a small signal types for the use in radio frequency, or in other low current applications which may be termed as signal diodes.
Other types can be intended for high current and high voltage applications and are normally termed as rectifier diodes. SCHOTTKY DIODES-also known as “PNPN” diode. Has a lower forward voltage drop than any other ordinary silicon PN junction diodes, equals to a thyristor its gate terminal is disconnected At low currents the drop may be somewhere in between 0.15 and 0.4 volts as opposed to 0.6 volts for a silicon diode.
It has two operating states which is conducting and non-conducting states. STEP RECOVERY DIODE-a type of microwave diode used to generate pulses at a very high frequencies. It is also known as a “snap-off diode” or “charge-storage diode”, these are also special types of diodes which stores the charges from the positive pulse and uses in the negative pulse of the sinusoidal signals. The application of these kind of diodes are in higher order of multipliers and in pulse shaper circuits. TUNNEL DIODE-A high speed switch of order in nano-seconds. Due to tunneling effect it has a very fast operation in microwave frequency region. It has a two terminal in which concentration of dopants is too high.
VARACTOR DIODE-A varactor diode is one kind of semiconductor microwave strong state gadget and it is utilized as a part of where the variable capacitance is picked which can be expert by controlling voltage. These diodes are likewise called as variceal diodes. Despite the fact that the o/p of the variable capacitance can be displayed by the ordinary PN-intersection diodes. But, this diode is decided for giving the favored capacitance changes as they are diverse sorts of diodes. These diodes are correctly outlined and upgraded with the end goal that they permit a high scope of changes in capacitance. It’s applications are voltage-controlled capacitors, voltage-controlled oscillators, parametric amplifiers, frequency multipliers. FM transmitters and Phase locked loops in radio, television sets and cellular telephone.
ZENER DIODE-It is like ordinary diode forward direction, it additionally permits current in reverse bias when the connected voltage achieves the breakdown voltage. It is intended to keep the other semiconductor gadgets from transient voltage beats. It goes about as voltage controller. CONSTANT CURRENT DIODES-it is otherwise called current-regulating diode or steady current diode or current-constraining diode or diode-associated transistor. The function of the diode is controlling the voltage at a specific current. It works as a two terminal current limiter. In this JFET goes about as present limiter to accomplish high yield impedance.
SHOCKLEY DIODE-It was the creation of first semiconductor gadgets it has four layers. It is additionally called as PNPN diode. It is equivalent to a thyristor without an gate terminal which implies the door terminal is detached. As there is no trigger information sources the main way the diode can direct is by giving forward voltage. It remains on one’s it turned “ON” and remains one’s it turned “OFF”.
The diode has two working states leading and non-direction. In non-directing state the diode conducts with less voltage. The application of trigger switches for SCR and acts as relaxation oscillator. TRANSIENT VOLTAGE SUPPRESSION DIODE -In semiconductor devices because of the sudden change in the state voltage drifters will happen. They will damage the device yield reaction.
To prevent this issue voltage suppression diode diodes are utilized. The operation of voltage suppression diode is like Zener diode operation. The operation of these diodes is typical as p-n junction diodes yet at the season of transient voltage its operation changes. In typical condition the impedance of the diode is high. At the point when any transient voltage happens in the circuit the diode enters in to the torrential slide breakdown district in which the low impedance is given.
VACCUM DIODES-consist of two terminals which will acts about as an anode and the cathode. Cathode is made up of tungsten which transmits the electrons toward anode. Continuously electron flows from cathode to anode as it were. In this way, it acts like a switch. In the event that the cathode is covered with oxide material then the electrons emission capacity is high. Anode is somewhat long in measure and now and again their surface is unpleasant to lessen the temperatures creating in the diode.
The diode will lead in just a single case that is the point at which the anode is sure in regards to cathode terminal. SILICON CONTROLLED RECTIFIER-consist of three terminals which are anode, cathode and a gate, also nearly equal to the Shockley diode. Its name indicates it mainly used for the control purpose when small voltages are applied in the circuit. AVALANCHE DIODE-passive component works under rule of avalanche breakdown. It works reversed bias condition. It comes about large current because of the ionization produced by p-n junction during reversed bias condition.
These diodes are uncommonly intended to experience breakdown at particular turn around voltage to prevent damage. PELTIER DIODE-type of diode, at the two material jucntion of a semiconductor it produces a heat which flows starting with one terminal then onto the next terminal. This flow is done just single direction that is as equivalent to the course of current stream. This heat is created because of electric charge delivered by the recombination of minority charge transporters.
This is mainly utilized as a part of cooling and warming applications. This sort of diodes utilized as sensor and heat motor for thermo electric cooling. SUPER BARRIER DIODES-a rectifier diode having low forward voltage drop as schottky diode with surge dealing with ability and low turn around leakage present as p-n intersection diode. It was intended for high power, quick exchanging and low-misfortune applications.
Super boundary rectifiers are the cutting edge rectifiers with low forward voltage than schottky diode. GOLD DOPED DIODES-these diodes gold is utilized as a dopant. These diodes are quicker than different diodes.
In these diodes the leakage current in turn reversed bias condition additionally less. Indeed, even at the higher voltage drop it enables the diode to work in signal frequencies. In these diodes gold aides for the quicker recombination of minority bearers. Discuss, illustrate and derive the related equations of various rectifier circuits.Half wave Rectifier During positive half cyclev_i-0.
7-v_o=0 During negative half cyclev_o=0Full wave Rectifier During this half of each input cycle, the diodes D1 and D4 are reverse biased and current is not allowed to flow in the D1 and D4 so the flow of the circuit is from the positive terminal to the D2 then across the resistor next is to the D3 and to the negative terminal. During the second half cycle of the input voltage ,thus diode D1 and D4 becomes forward bias and current flows through and current is not allowed to flow to D2 and D3 the flow of the circuit is from the negative terminal to the D4 then across the resistor next is to the D1 and to the positive terminal. Input and output waveforms Discuss the block diagram of a power supply. You may illustrate it and the corresponding waveforms. The block diagram, the basic power supply is constructed by four components a transformer, a rectifier, a filter, and a regulator set up together.
The output of the dc control supply is utilized to give a consistent dc voltage across the loop. Transformer is utilized to step up or step down the-supply voltage according to need of the strong state electronic devices and circuits to be provided by the dc power supply. It can give isolation from the supply line-an imperative security thoughtout. It might likewise include the inner protecting to avert undesirable electrical noise signal on the electrical power line or cable from getting into the power supply and potentially disturbing the load. Then the next step is rectifier transforms or changes the secondary winding AC voltage into a pulsating DC voltage. Next is the filter, formed by at least one capacitors, straightens or smoothens the past waveform eliminating the exchanging current (AC) component delivered by the rectifier. These capacitors are charged to the maximum voltage value that the rectifier can carry, and they are released when the pulsating signal disappears. And finally, the voltage regulator receives the signal from the filter and carry a constant voltage regardless to the minor departure from the load or the voltage supply.
State other applications of a diode. (rectifier circuit is an application of diode) Diode as a Rectifier: The most widely recognized and critical utilization of a diode is the rectification of AC power to DC power. Utilizing the diodes, we can construct different sorts of rectifier circuits.
The essential sorts of these rectifier circuits are half wave, full wave center tapped and full bridge rectifiers. A single or combination of four diodes is utilized as a part of the majority of the power conversion applications. Diodes in Clipping Circuits: Clipping circuits are utilized as a part of FM transmitters where noise peaks are constrained to a specific value with the aim that excessive peaks are eliminated from them. The clipper circuit is utilized to put off the voltage beyond the preset value without disturbing the rest of the part of the input waveform. Based on the diode setup in the circuit, these clippers are isolated into two sorts; series and shunt clippers and again these are characterized into various sorts. Diodes in Clamping Circuits: A clamper circuit is utilized to move or shift either positive or negative peak of an information flag to a coveted level. This circuit is additionally called as level shifter or DC restorer.
These cinching circuits can be sure or negative relies upon the diode arrangement. In positive cinching circuit, negative pinnacles are raised upwards so the negative pinnacles fall on the zero level. If there should be an occurrence of the negative bracing circuit, positive pinnacles are cinched with the goal that it pushes downwards to such an extent that the positive pinnacles fall on the zero level. DIODES IN LOGIC GATES: Diodes can likewise perform computerized rationale operations. Low and high impedance conditions of rationale change are practically equivalent to the forward and turn around one-sided states of the diode individually. Accordingly, the diode can perform rationale operations, for example, AND, OR, and so on. Despite the fact that diode rationale is a prior technique with a few impediments, these are utilized as a part of a few applications. The underneath figure demonstrates the OR entryway rationale executed utilizing a couple of diodes and a resistor.
DIODES IN VOLTAGE MULTIPLIER CIRCUITS: Voltage multiplier comprise of at least two diode rectifier circuits which are cascaded to produce a DC output voltage equivalent to the multiplier of the connected intput voltage. These multiplier circuits are of various sorts like voltage doubler, tripler, quadrupler, and so on. By the use of diodes combination with capacitors, we get the odd or even multiple input peak voltage at the output. DIODES IN REVERSE CURRENT PROTECTION: The reverse polarity or current protection is important to stay away from being damage that happens because of interfacing the battery wrongly or switching the polarities of the DC supply. This incorrectness of connection of the supply causes to flow a substantial sum present of current, thorough the circuit parts results to explode them. In this way, a defensive or blocking diode is associated in arrangement with the positive side of the contribution to prevent a reverse connection problem. DIODES IN VOLTAGE SPIKE SUPPRESSION: If there should be an occurrence of an inductor or inductive load, sudden removal of supply source delivers a higher voltage because of its stored magnetic field energy.
These startling spikes in the voltage can make the significant damage the circuit segments. Consequently, a diode is connecter across the inductor or inductive load to restrict the huge voltage spikes. These diodes are additionally called by various names in various circuits, for example, snubber diode, flyback diode, suppression diode, and freewheeling diode and so on.
DIODES IN SOLAR PANELS: diodes which are utilized for security of solar panels are called as “bypass diodes”. In the event that the solar panel is broken or harmed or shaded by fallen leaves, snow, the overall output power decreases and up rise a problem area of the fact that the current of whatever remains of the cells must flow through this defective or shaded cell causes an overheating. The primary capacity of the bypass diode is to ensure the sun oriented cells against this problem area warming or heating issue.