A resistor is basically defined as a device that offers resistance to the flow of current in a circuit. It is among the other components of a circuit referred to as passive circuit components. They are called passive because their operation is not dependent on the power itself. Others in this category include transformers, capacitors, and inductors. All electrical components must have a resistor of some sort. They serve the purpose of limiting the amount of electric current flowing through the circuit so that other components are not damaged. There are an unlimited number and types of resistors available in the market today, which makes it virtually impossible to know which one to select for a particular application the following are some of the basic properties of a resistor to consider when sleeting them for use.
The first property is the resistor tolerance. Tolerance reference to the range by which the actual value of resistance varies from the stated value. It is normally given in form of percentages and always ranges between 1% and 10%. High precision resistors have tolerance values of about 1% or even below, meaning that they give very accurate readings of resistance. There are more info you can get about high power resistors.
The next is the power rating of the resistor. The power rating for a resistor is defined as the amount of power that can be consumed by the resistor without it being damaged. In most cases, the value of power rating indicates the average, and not the instantaneous, power consumption. This means that when you are selecting a resistor to buy, you would be safer if you selected one whose power rating is double that which flows in the circuit so as to protect the device from overloading.
Temperature rating is another important characteristic to consider. It refers to the temperature range within which a particular resistor can function optimally. Because the value of resistance of a resistor is affected by temperature, it is important to match the temperature rating on the resistor with the ambient operating temperature on the circuit board. This will ensure that the resistor is able to serve you well for a longer period of time. All of your questions about resistor will be answered when you click the link.
The temperature coefficient of resistance, on the other hand, is the value by which the resistance of a resistor changes from 25oC. It is normally given in parts per million. The coefficient resistance for a resistor majorly depends on the material used in the design as well as the size of the resistor. Knowledge of these and other properties of a resistor will enable you as the buyer to select the appropriate resistor that you have need of.