Factors Governing the Choice Of Custom Resistors
Resistors play a very important role in all electrical circuits. Any electrical connection cannot be complete without a kind of resistor. In order to prevent the damage of other components in a circuit by excess current, a resistor is used to provide resistance to the current.
There are two types of resistors; namely fixed resistors whose resistance doesn’t change, and variable ones whose resistance changes depending on other components of the circuit. With the technology changing and advancing every day, there has arisen a need for a third category of resistors, the custom resistors. Custom resistors are produced to work on custom-made devices. They are also called precision resistors by virtue of their precision and high degree of accuracy in their operation. When selecting a custom resistor to use in a device, a number of factors are considered. Some of these factors are outlined below.
The necessary resistance for the circuit to operate. Before you select a custom resistor to use in an electronic device, you ought to know the amount of resistance which is necessary for that particular circuit. This will form the value of the resistor that you are going to choose. Resistance is value is given in Ohms and is measured using an ohmmeter. Once this value has been established, you can then look for a custom resistor that fits it.
Another factor that determines resistor choice is the power rating of the resistor. The amount of electrical power lost by the resistor in Watts is referred to as the power rating of the resistor. Power in an electrical circuit depends on the current, resistance and voltage. Amount of power is computed as the value obtained by dividing the square of voltage by the resistance. So, once the two values of voltage and resistance are known, power rating for the resistor is calculated, and this information is used when choosing the custom resistor to fit the circuit.
You also have to factor in resistor construction when selecting a custom resistor. Construction in this regard has to do with the type of material used to make it. There are different kinds of material used in the construction of custom resistors. Carbon composition, metal films, thick and thin films as well as foils are some of these materials. The effectiveness in resisting a current will normally depend on the material used.
Type of fixing made on the circuit. The style in which the resistor is to be mounted into the circuit is also an important consideration to have in mind. Resistors could be bracket mounted, panel mount, PC or surface mount types. The kind of device into which the resistor is to be placed is what determines the kind of mounting to be used. So, ensure that you select the appropriate mounting for your custom resistor.