Resistors are an integral part of any electrical or electronic circuit. Resistors do not do much to clearly be identified within the circuit. As named they limit the flow of current inside 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. If for instance there is too much current going to a light bulb it will be damaged. In this way a resistor is a guardian to other sections of the circuit.
Variations in systems means different levels of resistance are needed. Custom resistors are therefore built to handle this. It is created to cater to the needs of that particular system. When picking a resistor for a system one should know how much heat the resistor can endure before it is rendered useless. Resistors 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 used to make the resistor is important as some materials may not be able certain temperatures. So a customer resistor should be made with consideration to how much heat is likely t be produced while it is in use.
The accuracy of a particular resistor is known as tolerance. It is hard to make a custom resistor that would be perfect for a system and the current 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.
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. The Surface mount resisters are made of either thin or thick metal foil. It should be noted that resistors made of thin foil are low-cost as compared to those made of thin foil. Variable resistors are good option to the static resistors. This is because they can be easily regulated between a wide range of values. These resistors are also known as rheostats and can often be found in components such as volume knobs.