Any electronic or electronic circuit has resistors as significant aspects. That noted they do not play an outstanding role. Resistors as the name suggests resist the flow of current within a circuit. The result of the resistors functioning is referred to as resistance which is measured in Ohms and represented by the sign omega. A resistor limits the quantity of power that gets to the other components of the system. An example would be when a bulb receives too much light the bulb will eventually 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 one made for a particular complex. The custom resistors are designed for specific systems. When picking a resistor for a system one should know how much heat the resistor can endure before it is rendered useless. Resistors are bound to heat up when current passes through them.
Resistors that are built for high resistance will be hotter than the ones with low resistance. 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.
The accuracy of a particular resistor is known as tolerance. It is impossible to make a resistor that is a hundred percent correct for a complex and the power flowing through it. Tolerance is gauged by plus or minus a certain percentage. A good example would be a 5 % resistor that has a value of 200 ohms will exhibit a resistance of between 210 ohms and 190 ohms.
Materials for making custom resistors are carbon, metal or ceramic. As noted above resisters build up heat as current flows through them. The material they are made of should be able to withstand the heat without for instance catching fire or melting. Modern day resistors are made of metal or carbon.
Resistors are made either surface-mount or through-hole mount termination designs. Through-hole mount are either made of carbon or metal film or very thin metal foil. The former is the cheaper option. Surface mount resistors, on the other hand, are normally made from 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. They are also called rheostats and are often used in such components as knobs for volume.