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?