NIT ANDHRA PRADESH VOLUME 2 ISSUE 6

The Official ECE Newsletter Issue date: 5th January, 2020

“Wishing you 12 months of success, 52 weeks of laughter, 365 days of fun, 8760 hours of joy, 525600 minutes of good luck and 31536000 seconds of happiness” ORGANIC LIGHT-EMITTING DIODES interactions which are called excitons. Recombination of an electron and hole from an exciton cause the emission of electromagnetic radiation and in this way, - P. Shilpa (611867) Organic light-emitting diodes (OLEDs) are solid-state light sources made of the molecule energetically turns back to its ground state as the last step. organic semiconductor (OSC) materials. Various functional materials help to The emitted photon wavelength then depends on the material. For example, facilitate the conversion of injected charges into emitted photons at the with AlQ3 green light around 520 nm is emitted. OLED devices fabricated for maximum possible efficiency and further are assembled specifically to realize large screens must provide three main colours (RGB—red green blue). On the the desired emitted colour—be it monochrome or broadband emissions for other hand, lighting studies for industrial applications focused on white colour displays or solid-state lighting (SSL), respectively. The materials used can be organic LEDs. Usually, white light can be obtained from the mixture of two or both small molecules (Tang and VanSlyke, 1987) and polymers (Burroughes et three main colours and that means we need to use at least two chromophoric al., 1990), where any possible combination of the two material classes best materials as the emission layer on the same device. meets the requirements with respect to desired applications and most suitable Organic Small Molecules and Polymers Semiconductor Material for OLED processability. With few exceptions, the organic materials can be made and Applications: upscaled at low cost, and their processing schemes suggest truly economic mass Material scientists production. For the first applications entering the market (i.e., small displays for have developed a handheld devices like smartphones and tablets), the production of such panels is large number of small already profitable. molecules used in OLED technology. Some representative small molecules used in OLED. White Organic Light-emitting Diodes: An organic light-emitting diode (OLED) is an electroluminescent light source that consists of an emissive semiconducting layer or layer stack, formed by organic molecules, sandwiched in between a pair of electrode layers. At least one of the electrode layers is optically transparent. When a direct current is passed through the device, light is emitted as a result of recombination of electrons and holes that are injected from the cathode and anode, respectively. Depending on the organic layer composition, the emission can be chosen either to be confined to a relatively narrow band in the optical spectrum, leading to a Working Mechanism of OLED: monochrome OLED or to be distributed over the entire visible part of the In a simple organic LED, whole device architectures can be fabricated by electromagnetic spectrum, leading to a white OLED. White OLEDs are studied solution process or thermal evaporation techniques. Although small molecules intensively for applications in lighting and displays. Displays based on white can be deposited by both of these methods, conjugated polymers can be OLED pixels that are covered with red, green, and blue colour filtering layers deposited only by solution process methods. The working steps of an are already commercially available, forming an alternative to OLED displays in electroluminescent device can be explained in a few steps. As a first step, charge which the pixels are based on different (red, green, and blue-emitting) organic carriers (electrons and holes) are injected from electrodes under an applied semiconductors. In liquid crystal displays, white OLEDs can serve as a electrical potential to the transport layer. These transport layers also act as backlight. blocking layers of the opposite charge types. In the emission layer (inside the REFERENCES luminescent material) electrons and holes can be captured by coulombs • R. Coehoorn, H. Boerner, in Encyclopedia of Materials: Science and Technology.

CONVOCATION 2019 • Shreya Kudari (EEE) - Institute and Branch 3. MOTHER TONGUE: He said, “Learn any Gold Medal language. But remember that any foreign -Mohan (611775) • Veramallu Jhanakeerti Priya (ECE) language is regarded as glasses to our Mother • Thota Devika (Bio-tech) tongue which is regarded as eyesight. Without • Kandavalli Himanandini (Chemical) eyesight even the costliest glasses are useless. • K. Jayashankar Reddy (CSE) So never forget our Mother tongue”. • Sriram Lakshmi Manasa (Civil) 4. JANMABHUMI. He said “Do something for • Msk Hemanth (Mechanical) the benefit of your birthplace”. • Aditya Bharadwaj (MME) 5. ALMA MATER. “No one should forget their Out of 379 students in the first batch, 275 Teachers. Every graduand should contribute to students attended and received their degree from the development of their college.” Our institute's first Convocation was held on 24-12- Honourable Director of NIT Andhra, Dr.CSP Rao. He suggested various areas where technological 19 at the permanent campus. Our Vice President Our Honourable State Governor Biswabhusan advancement is needed like Weather forecast, Solar Muppavarapu Venkaiah Naidu along with Andhra Harichandan advised students that they shouldn’t energy, Water management, new methods to recycle Pradesh State Governor Biswabhusan Harichandan, fail in performing their fundamental duties as waste materials, Agriculture Market management IIT Tirupati director Professor K.N. Satyanarayana citizens of and also advised all the Graduands and developing new methods for implementing attended the convocation as Chief guests. West not to be complacent with what they have achieved Government Schemes through online portals. Godavari Collector Revu Mutyala Raju, Ex MLA till date and not to stop until their dreams are IIT Tirupati director Dr. K.N. Satyanarayana Pydikondala Manikyala Rao, State Cabinet achieved. appreciated SHIRKE company for their effort in Ministers Taneti Vanitha, Sri Ranganatha Raju and The main attraction of the event, Honourable Vice completing the construction in such a short time. He MP Raghu Rama Krishna Raju and Tadepalligudem , Venkaiah Naidu gave a thought- suggested that the graduands shouldn’t forget about MLA Kottu Satyanarayana attended the provoking speech. He advised the graduands not to their college and should contribute to the Convocation along with chief guests. forget about five things: development of the college. 1. PARENTS After IIT director’s speech, Our director distributed Gold Medals (8 individual Branch toppers and an 2. MOTHERLAND: He advised students who degrees to Graduands. With a vote of thanks to the Institute Gold Medal) were awarded by Vice wished to study in foreign countries, “GO. chief guests, the dignitaries, the Graduands and their President Venkaiah Naidu to the following students: LEARN. EARN. RETURN” to serve the parents, the first convocation of our NIT was motherland. brought to an end. PAGE 1 GATE PROBLEMS Electromagnetic interference -Sourav(611785) 1. For a Super heterodyne receiver, the intermediate Before knowing about EMI filter, frequency is 15 MHz and the local oscillator frequency first we need to know what EMI is. is 3.5GHz. If the frequency of the received signal is Electromagnetic interference (EMI), greater than the local oscillator frequency , then the occurs when an electronic device is image frequency (in MHz) is ____ affected or interrupted by unwanted signals (noise) that are generated either by its own internal integrated 2. A Device with input x(t) and output y(t) is characterized electronic devices (intra EMI) or by by y(t) = x2 t . An FM signal with frequency deviation other surrounding external of 90KHz and modulating signal of bandwidth of 5KHz electronic devices (inter EMI). This is applied to this device. The Bandwidth of output signal effect of interrupting the intended is currents of the devices by the A. 370 KHz unwanted disruptive currents can also be called as electromagnetic B. 190 KHz noise. Depending on the severity of the disruption, EMI may impact the quality of C. 380 KHz the signal the device receives, may cause a component to fail or malfunction D. 95 KHz temporarily or permanently damage the electronic device. EMI can also be categorized in many ways based on the duration of the signal, band width and also **Solutions to the previous issue questions are included in the e-copy by the source which generates the EMI, the interference can be continuous or sporadic. Sporadic EMI occurs when the source is lightning which causes temporary interruptions. Basically EMI is of two types, radiated EMI and conducted EMI. EDITOR’S NOTE Conducted EMI goes through conductors such as wires, while radiated EMI travels through the air and does not require a conductor. The noise that falls on the radio Hello readers!! We are back with volume 2 issue 6 edition of ECE frequency spectrum within the electromagnetic frequency spectrum is known as Hearld newsletter. Hope you will cherish our efforts. Firstly, An article Radio frequency interference (RFI) which is a subset of electromagnetic interference is drafted regarding the splendid convocation of the first batch of the (EMI) . RFI includes only electromagnetic currents with a frequency between 3kHz institute which also states the gold medalists of the institute. Secondly, to 300GHz. RFI is the major problem nowadays, which consist of conducted RFI A fascinating note regarding Organic LEDs in penned. A short note and radiated RFI and can cause a variety of problems with electronic devices. about electromagnetic interference is written in the newsletter. An Sources of EMI: article regarding electronic tattoo is elaborated in the newsletter. An ● EMI’s which are generated by lightning strikes, cosmic noise, atmospheric introduction about Zigbee technology is drafted. Some more interesting electrical storms, solar magnetic storms, dust storms, snow storms are and creative stuff like gate problems, upcoming events, Techatoon, Art uncontrollable natural interrupts. works and pic of the month add on its own elegance to the newsletter. ● EMI’s which come from devices that operate using a wireless signal, but also Lastly, An article regarding the working and usage of biometric voting emanate from a variety of other electronic appliances such as mobiles, Wi-Fi machine is put forward. devices, micro-ovens, heaters, lamps. All your recommendations will be considered and are always ● Cellular networks, television and cell welcomed. We are expecting an enthusiastic contribution to the phone transmissions radiate high newsletter, be it an article of your own interest or artworks or any other electromagnetic noise. Radio, satellite interesting stuffs. communications which consists of high For any questions, suggestions, ideas, articles or artworks please contact frequency signals also radiate EMI and us at [email protected]. interrupts or induce noise to several Keep reading and keep contributing!!Happy reading!!. other externally presented electronic devices .

EMI filters : TECHATOON ● EMI filter is an effective way to protect the desirable currents to flow freely against the harmful impacts of electromagnetic interference. EMI filters can suppress and extract unwanted electromagnetic noise transmitted through conduction and helps in allowing intended currents. EMI filters that suppress noise from grid power are also called EMI power line filters. ● As most of the electromagnetic noise frequencies are high, this EMI filter acts like a basic low pass filter, rejects these unwanted disruptive signals and diverts the electromagnetic noise from the device to the ground. Some EMI filters may also route unwanted currents back to the noise source or absorb them. ● These EMI filters can effectively block only conducted EMI but it can also avoid radiated EMI by adding a shield to the filter. ● The unshielded EMI filter can block conducted EMI but transmits noise through air which comes under radiated EMI. So adding a shield at the attachment point of the electromagnetic interference filter can effectively block all forms of EMI. Types of EMI filters and their applications: ● White goods EMI filters can block the noise that are generated by home appliances like treadmills, washing machine, refrigerator etc. ● Medical grade EMI filters help in protecting sensitive medical equipment from damage. Majorly, in many medical equipment cables, these filters are mainly used because small interrupt can damage the total functioning of the equipment. ● Single-phase EMI filters, Three-phase EMI filters are generally used in telecommunications, satellite communications, three-phase motors, military and also in industrial tools . ● Even though there are several EMI filters, there still exists a problem faced by the researchers in blocking the noise as they destroy the original signal. ● In modern power converters, achieving high efficiency is a main concern and is a key factor to save energy but it is a very challenging task as we need to compromise with key factors such as quality and power density. It is apparent that in power electronics, increasing the switching speed and decreasing the switching frequency ,decreases the switching loss, but the main drawbacks are increase in the EMI noise and reduction in the quality of power converters. PAGE 2 ELECTRONIC TATTOO more like a thin circuitry-filled sticker. Instead, it reads your body variations and whispers that data to the physicians. Silicon provided the first major -Anusha (611717) hurdle to this world of skin-soft cybernetics. These tiny silicon wires are Electronic Tattoo, Sounds crazy arranged in coiling patterns and are woven through slender rubber patches. right!! Temporary tattoos are a fun These coils expand, they contract and link all the functional parts of the device way to express yourself, but what if from the sensors and antenna to LED lights. Thus, making this rigid they could also tell you when you’re technology bendable and stretchable. getting too much sun, Exposed to Thus making an application of not having EEG to measure brain waves. Just environmental pollutants or your slap a patch on your forehead, apply some over-the-counter liquid bandage health conditions? It’s amazing spray. The patch collects energy from the sun, reads your vitals and then right. This technology is even more transfers the data out to an external device. Earlier models depend on a wired amazing something that may save connection between patch and computer. But improved models include Wi-Fi untold lives and become a staple of and network compatibility. Early electronic tattoos monitored muscle, heart modern medical care. These are epidermal electronics: thin, flexible patches and brain activity. From there, the developers expanded into pregnancy of rubber that contain equally flexible electrical components silicon wires monitoring in humans and actual muscle stimulation in rats. mere nanometers in thickness. This thin film of elastic gadgetry is essentially a Once, researchers placed an epidermal electronic device on their hand and temporary tattoo. The low-cost process adds trace amounts of an electrically- used muscle movements to control a computer game. They spoke a word and conductive, liquid metal alloy to tattoo paper that adhere to human skin. These the virtual game world responded. From here, the researchers imagined a ultrathin tattoos can be applied easily with water, the same way one would world where such patches pick up on the muscular movements of speech to apply a child’s decorative tattoo with a sponge. Because they have mechanical give voice to the mute and allow to covert military operatives to speak silently properties similar to lightweight fabrics, they remain functional under to their home base. This technology is the power of the next generation of bending, folding, twisting, and strains above 30% (which is the typical stretch wearable devices. This is going to become a revolution of new technology in ability of human skin). They can conform and adhere to highly curved 3D the field of electronic devices. surfaces. But an electronic tattoo looks less like a fire-breathing dragon and ZIGBEE TECHNOLOGY receiving signals respectively. initiating and managing the devices over the MAC Layer: This layer is responsible for reliable network. All other devices are called end devices - Karisma Panda(611736) transmission of data by accessing different networks that directly communicate with the coordinator. This ZigBee is a wireless networking protocol. The with the carrier sense multiple access collision is used in industries where all the endpoint devices ZigBee name came from erratic, zig-zagging avoidances (CSMA). This also transmits the beacon are needed to communicate with the central patterns of bees between flowers which symbolizes frames for synchronizing communication. controller, as this topology is simple and easy to communication between nodes in a mesh network. It Network Layer: It takes care of all network-related deploy. is a technological standard of IEEE which is used to operations such as network setup, end device create personal area networks with small, low-power connection and disconnection to network, routing digital radios, such as for home automation, medical and device configurations. device data collection, and other low-power low- Application Support Sub-Layer: It is responsible bandwidth needs, designed for small scale projects for matching two devices according to their services which need wireless connection. Hence, ZigBee is a and needs. low-power, low data rate, and close proximity Application Framework: It provides two types of wireless ad hoc network. It supports different data services as a key-value pair and generic network configurations for master to master or message services. The generic message is a master to slave communications. And also, it can be developer-defined structure, whereas the key-value operated in different modes, as a result, the battery pair is used for getting attributes within the In mesh and tree topologies, the ZigBee network is power is conserved. ZigBee networks are extendable application objects. ZDO provides an interface extended with several routers where the coordinator with the use of routers and allow many nodes to between application objects and the APS layer in is responsible for starting them. These structures interconnect with each other for building a wider ZigBee devices. It is responsible for detecting, allow any device to communicate with any other area network. initiating and binding other devices to the network. adjacent node for providing redundancy to the data. OPERATING MODES: ZigBee two way data is If any node fails, the information is routed transferred in two modes: Non-beacon automatically to other devices by these topologies. mode and Beacon mode. In beacon mode, As redundancy is the main factor in industries, mesh coordinator allocates a particular time slot to each topology is mostly used. In a cluster-tree network, device, known as Guaranteed Time Slot (GTS). Here each cluster consists of a coordinator with leaf all the devices in the network need to be nodes, and these coordinators are connected to synchronized. Clock synchronization is ensured by parent coordinator which initiates the entire network. sending a Beacon signal from the coordinator to Due to the advantages of ZigBee technology like each device (node). However, this may end up low cost and low power operating modes and its reducing the battery life of devices when not topologies, this short-range communication performing any other task than synchronizing their technology is best suited for several applications ZIGBEE ARCHITECTURE: ZigBee system clock. Once the device is synchronized, it can compared to other proprietary communications, such structure consists of three different types of devices transmit data to the coordinator using the CSMA- as Bluetooth, Wi-Fi. such as ZigBee coordinator, Router and End CA method. APPLICATIONS: device. Every ZigBee network must consist of at In a non-beacon state, the coordinator does not Industrial Automation: In manufacturing and least one coordinator which acts as a root and bridge transmit any Beacon message. Rather, each device production industries, a communication link of the network. The coordinator is responsible for transmits data using the CSMA-CA method in the continually monitors various parameters and critical handling and storing the information while same frequency channel. The device transmits the equipment. Hence ZigBee considerably reduces this performing receiving and transmitting data data as soon as the channel is clear. For transfer of communication cost as well as optimizes the control operations. ZigBee routers act as intermediary data from Coordinator to device, the device first process for greater reliability. Home devices that permit data to pass to and fro through sends a data request message to the Coordinator and Automation: ZigBee is perfectly suited for them to other devices. End devices have limited on availability of data, the coordinator controlling home appliances remotely such as a functionality to communicate with the parent nodes transmits the data message with a null length lighting system control, appliance control, heating such that the battery power is saved. The number of payload. For no pending data, the coordinator and cooling system control, safety equipment routers, coordinators and end devices depends on the sends an acknowledgement indicating no data operations and control, type of networks such as star, tree and mesh pending. surveillance. networks. ZigBee protocol architecture consists of a Smart Metering: ZigBee remote operations in stack of various layers where IEEE 802.15.4 is TOPOLOGIES: ZigBee supports several network smart metering include energy consumption defined by physical and MAC layers while this topologies, however, the most commonly used response, pricing support, security over power theft. protocol is completed by accumulating ZigBee’s configurations are star, mesh and cluster Smart Grid monitoring: ZigBee operations here network and application layer. tree topologies. Any topology consists of one or involve remote temperature monitoring, fault Physical Layer: This layer does modulation and more coordinator. In a star topology, the network locating, and reactive power management. demodulation operations on transmitting and consists of one coordinator which is responsible for PAGE 3 UPCOMING EVENTS IN OTHER INSTITUTIONS: • IIT - (Jan 27 -Feb7) : Event on Short term course on cyber security • IIT Madras (Feb 2): Kazien robotics program • IIT Madras (Jan 4) :Workshop on AI with machine learning • IIT Hyderabad (Jan 18 &19): Digital marketing workshop 2020 • IIT Indore (Jan 30 -Feb 1) :Fluxus – techno cultural fest • IIT Bombay (Jan 25& 26) :Aakaar technical workshop • NIT Warangal (Jan 6 to Jan 15) :Short term program on artificial Intelligence Workshop on data science • IIT (Jan 31st to Feb 2) : -technical fest

BIOMETRIC VOTING MACHINE -A. Maheswari Durga (611802) The objective of voting is to allow voters to exercise their right to express their choices V. Rahul regarding specific issues, pieces of legislation, citizen initiatives, constitutional amendments, III ECE recalls and to choose their government and Political representatives. Technology is being used more and more as a tool to assist to cast their vote. The field of biometrics was formed and has since expanded on to many types of physical identification. Still, the human fingerprint remains a very basic A R T W O R K S identifier and the biometric method of choice among law enforcement. Nearly everyone in the world is born with a unique fingerprint, a separate and comprehensively identifying attribute that sets us apart from the other 7 billion people that inhabit this world. It is because of this fact that the fingerprint has proven such a useful part of biometric security. The very reason that fingerprint scanners are useful can be found in this fact as well. Finger Print Sensor Module in Voting Machine: Finger Print Sensor Module or Finger Print Scanner is a module which captures fingerprint’s image and then converts it into the equivalent template and saves them into its memory on selected ID (location) by Arduino. Here, all the process is commanded by Arduino like taking an image of a fingerprint, convert it into templates and storing location etc. In this Finger Print Voting Machine Circuit, the Finger Print Sensor Module to authenticate true voter by taking their finger input in the system, 5 push buttons to Match, Enrol/back, Delete/OK, UP and Down are being used. Working: Working of this Biometric Voting System for Election is a little bit complex Meghana (611756) Laxmi Inisha(611712) for beginners. First of all, the user needs to enrol finger or voters with the help of pushbuttons/keys. To do this the user need to press ENROL key and then LCD asks for entering location/ID where finger will be stored. So now the user needs to enter the ID (Location) by using UP/DOWN keys. After Sending you smiles for every selecting Location/ID user needs to press an OK key (DEL key). Now LCD moment of your special day. will ask for placing finger over the fingerprint module. Now the user needs to put his/her finger over the fingerprint module. Then LCD will ask to remove K. KRISHNA PRIYA-12thJan the finger from fingerprint module and again ask for placing the finger. Now th the user needs to put his finger again over the fingerprint module. Now B. SAITEJA-26 Jan fingerprint module takes an image and converts it into templates and stores it HIMAJA.P-30thJan by selected ID into the fingerprint module’s memory. Now voter will be Y. SAI MOHITH-3thFeb registered and he/she can vote. By the same method, all the voters can be registered into the system. Voting Process: Now when the user wants to vote then he/she needs to press match key and then the buzzer will beep and LED will also glow and LCD will ask for place finger over fingerprint module. Now Arduino will give you three attempts to put your finger. After placing a finger over the fingerprint module captures finger image find its IDs is present in the system. If finger ID detected then LCD will show authorized Voter. It means the user is authorized to vote. And then the system moves to the next stage for voting. Now Green LED will glow, it means now voter can vote for their candidates by pressing a selected EDITORS key (from RED breadboard in this demonstration). Now if the same voter 풓풅 wants to vote again then the system will show it ‘Already Voted’. Means the Kartheek (ퟑ ECE) same voter can’t vote again and the buzzer will beep for 5 seconds. If any Meghana (ퟑ풓풅 ECE) Non-registered user wants to vote then the fingerprint module will not detect nd its ID into the system and LCD will show ‘No Fingerprint Found’. T H E Apoorva (2 ECE) DESIGNERS Advantages: TEAM 풓풅 1. It is highly reliable, secure and possible to get instantaneous results and Sankeerth (ퟑ ECE) with high accuracy. 풓풅 2. In the long run, the maintenance cost is very less when compared to the Hrushikesh (ퟑ ECE) present systems. Bhagavan (ퟑ풓풅 ECE) 3. Illegal practices like rigging in elections can be checked. Roshan (ퟑ풓풅 ECE)

PAGE 4 PREVIOUS ISSUE GATE PROBLEMS SOLUTIONS

1. Saturation current In a MOSFET is given by

μ 퐶 푤 퐼 = 푛 표푥. . (푉 − 푉 )2 퐷 2 푙 푔푠 푇

On substituting values we get

300 ×3.45 × 10−7 10 = × × (5 − 0.7)2 2 1

i.e., 퐼퐷 = 25.5 mA

2. 푉 푚 2 푛 2 For a rectangular waveguide; 푓 = + 푐 2 푎 푏

푉 1 2 푉 퐹표푟 푇퐸 , 푚 = 1, 푛 = 0 ⇒ 푓 = = 10 푐1 2 2 2푎

푉 1 2 1 2 퐹표푟 푇퐸 , 푚 = 1, 푛 = 1 ⇒ 푓 = + 11 푐2 2 푎 푏

푓푐 1 푉/2푎 1 Given 1 = ⇒ = 푓푐 2 푉 1 2 1 2 2 2 + 2 푎 푏

푎 1 푎 ⇒ = ⇒ 4푏2 = 푎2 + 푏2 ⇒ = 3 푎2 + 푏2 2 푏

풘풊풅풕풉 Therefore = ퟏ. ퟕퟑퟐ. 풉풆풊품풉풕