In earlier, the most important and critical component used in an electronic device is a vacuum tube, used to control the flow of an electrical current. Vacuum tubes are bulky and need high power consumption, yield lower efficiency, higher operating voltages and also used electron materials which emit electrons for operation. So, that ended up as heat, which reduced the life of the tube itself. To overcome these complications, Walter Brattain, William Shockley and John Bardeen were developed a transistor at “Bell Labs” in the year of 1947. The transistor was a much smarter solution to overcome several of the essential limitations of vacuum tubes. This article gives an overview of transistor construction, types, applications,etc.
The Basic requirement of safety can be conquered by designing several door locks for security like electrical locks and mechanical locks. The designing of these door locks can be designed with one or multiple keys, but for securing a big area we need various locks. Normally, old-style locks are weighty and that are not solid as they can harm simply by using some gears. Electronic locks are superior over mechanical locks, to resolve the problems of security that are allied with the mechanical locks. Nowadays, every device uses digital technology. For a sample, door lock system using digital technology, recognition of digital device using a token, automatic door closing and opening, RFID door lock systems, etc. These kinds of systems are used for movement controlling of a door without using a key.
The resistor is a passive two terminal electrical components, that are used in most of the circuits. The resistors act as the lower voltage levels within the circuit and it is also used for reducing the current. The high power resistors can drive may watts of electrical power like heat. It is used for the motor controls in power distribution system. By using the temperature, time, and operating voltage can change the resistance of a fixed resistance. In the circuit elements the variable resistors are used in the form of light, sensing device to heat, chemical activity, and force. In the electrical networks and in electrical circuits the resistor is the common components. The different types of resistors are present everywhere in the electronic equipment and in the integrated circuits the resistors are implemented. If the practical resistors are discrete components, then it collects different types of components. The resistor of electrical function is specified by the resistance. The manufacture of resistors has a range of more than the nine orders of magnitude. By using the tolerance the value of the resistor is indicated.
What is a Resistor?
The resistor is a component, designed to find the known values of resistance. The resistors are also known as the passive components. The resistors are used for reducing the current in the circuits. The basic symbol of the resistor is shown in the below.
Different Types of Resistors
There are some different types of resistors in the electronic circuits. Depending upon the manufacture and contraction the resistance has different properties. It makes the difference in their applications. The resistors are available in different sizes and shapes in the market. The different types of resistor are discussed in the following section.
- Linear resistors.
- Non-linear resistors.
The resistor values are changed with the help of the temperature and applied voltages are called linear resistors. If the resistance of the current value is directly proportional to the applied voltage is called the linear resistance. The linear resistors are two different types of resistor which are the following.
- Fixed resistors
- Variable resistor
The name itself says that fixed resistor. So the values of the specific resistor cannot change in the fixed resistor. There are different types of the resistor which are in the following.
- Led arrangement
- Carbon composition
- Carbon Pile
- Carbon film
- Printed carbon resistor
- Thick and thin film
- Metal film
- Metal oxide film
- Wire wound
- Foil resistor
- Ammeter shunt
- Grid resistor
- Special verities
Carbon Composition Resistor
The carbon composition resistor is made from the mixer of granulated or graphite, insulation filter and a resin binder. The actual resistance of the resistor is determined by the ratio of the insulation material. The shape of the insulating binder is in the shape of roads and there are two metal caps at both the end of the roads. At both ends of the resistor it has two wire conductors for easy to connectivity in the circuit design. There are different colors which are printed on the resistor to find the value of it and the road is covered with the plastic coat.
- The composition resistor is used in the high energy pulses.
- It has a relatively small size.
- High voltage power supplies
- High power
This type of resistor is prepared with the stack of compressed disk between two metal plates which are in contact. These resistors are integrated in automatic voltage regulators and it controls the field current to maintain the constant voltage. The symbol of the carbon pile resistor is shown below.
- These are used in the speed control small controls small motor in home appliances.
- This type of resistors is available in carbon microphone.
- Carbon pile resistors are used in the adjustable load resistors if it requires like radio transmitter or automatic batteries.
The carbon film resistor is formed by cracking the hydrocarbon in a ceramic former and the temperature coefficient is from the -100 to -900 ppm/°C. The carbon film resistors are not using in the market because of the superior resistors are available in the market. These resistors are obtainable in small wattage levels. The symbol of the carbon film resistor is shown below.
The carbon film resistors are available in High plus stability.
Printed Carbon Resistor
The name itself says that the “printed” so this type of resistors are used on the printed circuit boards. These types of resistors are mostly common in hybrid PCB modules. The tolerance of these resistors is quite large and it is in the order of 30%. The symbol of this resistor is shown below.
- This type of resistors is used in the standard fiberglass in PCB’s.
- It has non critical pull up resistor.
Thick and Thin Film
In 1970s the thick film resistors are more popular and nowadays this type of resistors is in surface mount device. The thick film is 1000 times thicker than the thin films with resistive elements. The principal of both, the difference is in film applied to cylinder surface mountain device resistor.
The thin film resistors are prepared by a method of vacuum deposition and the resistive material are through the insulating substrate. The old process of making the printed circuit board is in film etched. The surface is covered with a photosensitive material and covered with a pattern film, irradiated with ultraviolet light and exposed to the sensitive coating. The manufacture of the thick film resistor is by using the screen and a stencil printing process.
- Thin film is usually used in precision applications.
- The thin film resistance features have a relatively high tolerance.
- The inductance and capacitors are generally low in thin film resistors.
- The thick film resistors are used in case of high tolerance.
- The thick film resistors are available in low price and it can handle low power.
- Thick film resistors have a wider range of resistors.
Metal Film Resistor
The construction of metal film resistors is similar like carbon film resistor. Instead of carbon there are a metal and metal is a mixture of nickel, chromium, metal glaze and metal oxides. The temperature coefficient of metal film resistor is very low and the value is +-2ppm/C. The symbol of metal film resistor is shown below.
- The tolerance of metal film resistor has good characteristics.
- The low voltage coefficient of this resistor has high linearity and low noise.
- In bridge circuit and active filter this film resistors are used.
Metal Oxide Film Resistors
The preparation of metal oxide film resistor is with the help of metal oxides and these resistors are fixed from the axial resistors. These resistors are confused with the metal oxide Caristors which are made with the help of zinc oxide, silicon carbide. The chemical deposition methods are produced with the help of metal oxide resistor. The pure metal gases like high temperature and low pressure involve in the deposition process.
- The application of metal oxide film resistors is mostly similar to the metal film resistor.
- The metal oxide film and metal film are the predominant resistors.
Wire Wound Resistors
This type of resistors is made up of the insulating the core to a resistive wire. The resistive wire is tungsten, manganese, nickel is allowed. These resistors are very costly and sensitive to test. This resistor is available in the range of 2 watt to 100 watt resistors. The wire wound resistors of Ohmic values are from the 1 ohm to 200l ohm.
- It has high security
- Accurate measurement and balance current control is required.
There are different types of variable resistors are following
- Adjustable resistor
- Resistance and decade boxes
- Special devices.
The adjustable resistors are also known as a rheostat. These resistors are two or three terminal device and used for the current limiting purpose through the manual operations. The accessible range of these resistors is from 3 to 200 watts. The power rating is between the 5 to 50 watts.
- It is a power control device.
- Speed of motors.
The potentiometers resistor will have an additional screw and it has a better efficiency of operation. The potentiometer resistors are also known as trimmers. By changing the position of the screw by rotating through small screw driver then the value of resistor can be changed. These resistors are made of carbon composition, carbon film, and wire materials. The range of this resistor is from 50 ohms to 5mega ohm.
- These are used in wide range of industries.
- It can be used in control input and position measurement.
The lead arrangements are from the through hole technology. The component of through –hole will have the leads. The body of leads is leaving axially the first one is in a line parallel with the past and having longest axis. The other one is leaving the body in radically. The other component is surface mount technology. In earlier days the through hole technologies are totally replaced with the point to point construction.
Thus, this is all about the different types of resistors and its application.We hope that by reading this article you have got a better understanding of the concept of different types of resistors and its applications. If you have any queries regarding this article or to implement electrical and electronic projects, please comment in the below section. Here is a question for you, what is the function of the Resistor?
In the year 1971 by Hans R. Camenzind has designed the 555 timer integrated circuit with the contract of Signetics. Later on it came to Dutch company which is Philips semiconductors. The manufacturing of 555 timer IC includes the transistors, diodes, and resistors on the silicon chip which are on the 8 – pin mini dual in line packages. There are different types of timers available like 556 which include the 14 pin dual in line package are gathering the 555s on one chip. The other types of timers are 558 and 559 for both timers. It contains 16 pin dual in line package. The temperature range of the NE555 timer is from 0 °C to +70 °C.
The SE555 part number is designed for the military purpose with a temperature range from -55 °C to +125 °C. This was accessible for both high reliability metal with low price of epoxy plastic packages. The 555 timer got the name from the three 5 k ohm resistors, but the number was assumed as an arbitrary and it is a hypothesized. In the 555 timer there is a low power version like 7555 and the COMS TLC555.
The Electronic notice board plays an essential role in public areas like shopping malls, educational institutions, offices, etc. The events, occasions or any other information, which has to be accepted to the students, will be displayed on the notice boards.In the proposed system, a person announces the news and he has to keep posted the news on all the notice boards in the public areas. Mostly, this will be seen during the examination time. A time table of the exams has to be given to the students by writing the information on the boards. But the entire process takes a lot of time to update the information on the board. To overcome this problem, this wireless electronic notice board has been developed which totally eliminates the manual operation.
Android Controlled Electronic Notice Board System
This project uses most demanding technologies like embedded systems and android.
Android Operating System
Android is a Linux based OS (operating system) and it is designed mainly for touch screen based gadgets like mobile phones, tablets, etc. This android operating system have developed in the past fifteen years initial from black & white phones to current smart phones. Android is One of the most extensively used mobile operating system. This software was founded in Palo Alto in California in the year 2003.
The android is a powerful operating system and it supports various applications in Smart phones. The applications of this OS are more advanced and comfortable for the users. The hardware part supports Android software, that is based on ARM architecture. It is an open source OS means that anyone can use it and it supports millions of apps available. This OS is available at low cost in the market due to this reason android is very popular.
Remotely Controlled Android based Electronic Notice Board
The Electronic Notice Board is the primary thing in most of the public places like institutions, organization, public utility places like bus stations, railway stations, airports and parks. But sticking various notices day-to-day is a difficult process. A separate person is required to take care of this notices display. This project deals with an advanced wireless notice board.
The main goal of this project is to develop a wireless electronic notice board that shows information when a notice is sent from the android device of the user. Operation of the remote can be attained by any android application, upon a Graphical User Interface based touch screen function.
The required hardware and software components are Micro controller unit (AT89C52), BLUETOOTH Device, LCD (16×2), Resistors, Capacitors, Diodes, Transformer, Regulator, Kiel compiler, Language: Embedded C Or Hex Assembly and Android Application
While the operator sends the information from the android OS based device, it is received and recovered by the Bluetooth device in the display unit. The password accessed by the Bluetooth device will only be known to the user. Then, it is sent to the microcontroller that further exhibits the notice sent from the mobile user on to the notice board which is inbuilt with an LCD display. It includes a 8051 family microcontroller.
The power supply unit comprises of a step down transformer, bridge rectifier, voltage regulator. Where a step down transformer step downs the 230v to 12V AC. This voltage is converted to DC using a bridge rectifier.A capacitive filter removes the ripples and then regulates the voltage to 5V using a voltage regulator. The final voltage is required for the desired operation of the microcontroller and other apparatus.
The proposed system overcomes the problem by initiating a wireless electronic notice board which is interfaced to an android application based device through the Bluetooth device. This device receives the information from the android device that is sent to a 8051 microcontroller family. This microcontroller displays the information on an LCD screen. The applications of this project can be used in public places like airports, colleges, railway stations, offices, or airports for displaying any announcement.
Advantages and Applications
The advantages and applications of this project mainly include the following
- No need of any difficult wires to display the information on the LCD as it is wireless.
- Easy to operate and Consumes less power. This circuit is handy.
- It is used to display the information wirelessly in public areas like bus stations, parks, railway stations, colleges and organizations etc.
Therefore, this is all about android controlled electronic notice board system. Finally from the given information we can conclude that, by introducing this wireless technology, we can make our communication more proficient and faster, with better effectiveness we can exhibit the information with less errors & maintenance.We hope that you have got a better understanding of this concept. Furthermore, any queries regarding this concept or electrical and electronics projects, please give your valuable suggestions by commenting in the comment section below. Here is a question for you What is an electronic notice board?