What is SMD Resistor? How many types of resistor are there? Resistor Resistor is the most commonly used component in any PCB. In today’s section, we will know that what is a resistor? What is SMD Resistor And why is it used in PCB? So first of all let us understand what a resistor is.
What is SMD Resistor?
- Resistor is a passive two terminal electrical component that, as a circuit element, applies electrical resistance.
- Or we can say that the component installed in PCB or any electronic circuit, through which an obstruction is created in the path of electric current, is called Resistor.
- And the barrier created by it is called resistance. It is represented by R. Its unit is ohms.
Why are resistors used in PCBs?
As we know that any electronic device needs voltage to function. But the whole device does not work on the same voltage. Its different parts or sections require a certain voltage to work.
So to fulfill this requirement, a resistor is applied to create a blockage in the current in the electric path of that section or to reduce the current. In this way, by putting one or more resistors in the electrical path of a section, we can supply voltage to it according to its need.
Types of Resistor – Types of Resistor
There are following 5 types of resistors-
- Simple Resistor
- Fuse Resistor
- Code Type Resistor
- Network Resistor
- Voltage Dependent Resistor
These resistors are installed in the highest quantity in any PCB. These are the smallest components of black color, so they are also called Thin Chip Resistor. To make this type of resistor, ceramic material is used in the form of thin flim. This substance is made by mixing chromium, sliver, and coach.
In PCB, Fuse Resistor plays the role of both Fuse and Resistor. The value of this type of resistor is 0. In any circuit, the fuse resistor is applied for protection, it becomes open when more current than necessary.
3.Code Type Resistor
Those resistors installed on the PCB, whose body is written on some type of code, are called code type resistors.
A group of resistors of one or more same value placed in the same package is called a network resistor. It is also called Package Resistor.
5.Voltage Dependent Resistor
As the name suggests, voltage dependent resistor depends on the voltage of the resistor. The value of the resistance of the voltage dependent resistor is determined by the current flowing through it. Its value is high at low current and its value is low at high current. It is also called VDR.
How Resistor is Checked by Digital Multimeter?
There are two methods to check resistor in mobile phone.–
Keeping the multimeter on the range of 2000K ohms, touch its probe on both ends of the resistor. If the value shows anything then the resistor is considered correct.
If it shows 1 then the resistor is open, and if it shows 0 then the resistor is shorted.
Putting the multimeter on beep mode and touching the probe at the end of the resistor, if some reading comes with beep, then the resistor is considered correct.
If 1 comes then the resister is open. Note- Some resistors do not make a beep sound due to high value, so if they show reading then it is considered correct.
Resistor Identification in PCB
Resistor Black color is the smallest component in PCB and it has Silver color on its side. There are only maximum resistors in the whole PCB.