First let us know what a resistor is.Therefore, a resistor is simply a device with resistance to the passage of current. Almost any electrical gadget has a resistor for it to work. Thus, choosing the right resistor is very crucial. Below are some factors to look into before selecting the best resistor.
The Quantity of Resistance Required through the Resistor
This one of the many most fundamental criteria factors for a resistor. Apart from resistance being one of the important factors, different factors like the range of temperature, circuit voltage requirements, noise and thermal considerations will also influence the choice of a resistor. To select the right resistor, first put in mind the amount of output current dissipated.This helps to know whether to pick a smaller resistor or a bigger one depending on what is expected of the device.
The Nature of Resistive Substance
For a higher accuracy, the best option would be the metal film. This is due to the less than one percent tolerance that the thin film possesses. By the process of sputtering, film vapor is deposited onto a substrate surface to the required thickness. From there the resistor is laser trimmed more. With more accuracy and tighter tolerance, the metal film possess minimal noise and are more immune to radio frequency.Therefore, they are more desirable in case you need a lower radio frequency.
The Temperature level
The temperature range goes directly with the amount of power produced.But one thing that most people overlook is the fact that as a resistor heats up when the resistance changes. With the addition to this change in resistance, the level of energy dispersed from the resistor will most probably change the moment the resistor heats up. When the temperature is already beyond the normal and the produced power remains high then expect to have a damaged resistor. So when the operating environment is below the maximum then it will be okay.But when the ambient temperature will be raised then there will be a need to factor in the de-rating and choose the right temperature ratings and power resistor.
Voltage valuation relates parallel and intimately to the capacity of the case. Physically smaller devices have less working voltage ratings due to their close contacts and could easily arc over.This means that with high systems like off-line power supplies there will be a need to use larger sized or maybe even more than one resistor in series. This is so as to get the voltage ratings to the whole circuit higher.