0Types of resistors
- Carbon resistor: These are low-cost resistors which can be used where high precision is not required. It is built of carbon particles with the binding resin of various proportions for different resistance values. The combination is encapsulated in a plastic case and made connected with metal caps at both ends of the axis of the resistor. These metal caps are of copper, and the leads of tinned copper at two ends are the output terminals of the resistor.
- Deposited carbon: Deposited carbon resistor is made by depositing carbon film on ceramic rods by dipping in a flask of methane solution and heating it by gas crackling phenomena.
- High voltage ink film: It consists of a ceramic base on which a special ink film is laid down in a helical band. They are capable of withstanding high voltage and are used for medical electronics, radar and cathode ray circuits. It may be used at voltages upto 1000 KV, and resistance ranges from 1KΩ to 100,000 MΩ.
- Metal film resistors: It consists of a ceramic core rod on which a helix ground path of a vaporized metal film in a vacuum is deposited. These resistors have a high tolerance and are extremely reliable.
- Metal glaze resistors: A mixture of metal glass is applied as a thick film on a ceramic substrate and then fired to form a metal glass film resistor. The value of the resistor depends on the amount of metal in the mixture. With helical grinding, the resistances from one ohm to several megaohms may be manufactured. Another example of a tinned oxide film on a glass substrate.
- Wire wound resistors: Wire wound resistors are of a different type from resistive film coating. Here a ceramic core is wound with drawn wire which has accurately controlled characteristics. The total resistor is coated with an insulator such as baked enamel. These are very costly.
Cermet(Ceramic metal): This kind of resistor find used on printed circuit boards. They are highly stable at high temperatures by firing certain metals blended with ceramics on a ceramic substrate. The value of resistance depends on the type of mix and thickness.
