Resistors are an important aspect of any electronic or electrical circuit. They do not do anything that would stand out within the circuit though. The purpose of the resistors is to resist the flow of current within a circuit. This is called resistance and is measured in ohms which represented by the Greek letter omega. Resistor controls the mount of current that reaches the other parts of the circuit. If for instance there is too much current going to a light bulb it will be damaged. From this functionality it is clear that the resistor protects other parts of the circuit.
Varying systems require varying levels of resistance. A custom resistor is therefore a resistor made for a specific system. They are designed for different systems and uses. Before purchasing a resistor, it is necessary for you understand the amount of heat the resistor can endure before wearing out. Resistors are bound to heat up when current passes through them.
A resistor which has higher limit will become warmer than one with lower limit. The material the resistor is made of may not be capable of handling certain temperatures and therefore it will be damaged at those temperatures. When making a custom resistor you should have in mind how much heat is likely to be produced while the resistor is functioning.
Tolerance refers to the accuracy of a particular resistor. It is impossible to make a resistor that is a hundred percent correct for a complex and the power flowing through it. The measure of tolerance or accuracy of a resistor will be designated as a plus or minus of a specific percentage. For instance, a 5% resistor with a value of 200 ohms has a resistance of between 190 ohms and 210 ohms.
The main materials used to make custom resistors are carbon, ceramics and metals. It has to be noted that the resistors will build up heat as current flows through. The material they are made of should be able to withstand the heat without for instance catching fire or melting. Most resistors today are made of metal or carbon.
They come in either surface-mount or through-hole mount termination types. Through-hole mount are either made of carbon or metal film or very thin metal foil. The former is much cheaper. The Surface mount resisters are made of either thin or thick metal foil. Thick foil resistors are cheaper than thin foil resistors. Equally a variable resistor is better than a static resistor. This is because they can be easily regulated between a wide range of values. These are called rheostats and are common in components such volume knobs.