Inside Carbon Film Resistor

November 02, 2019

Adjusting the clamping pressure changes the resistance between the plates. A spiral cut is made in the film to increase the resistive path.

Carbon Composition Resistor Resistor Guide

What Is A Resistor

1w 220 Ohm Allen Bradley Carbon Comp Resistor Rc32gf221j

A thin pure carbon film is deposited on an insulating cylindrical core.

Inside carbon film resistor. Operating temperatures are up to 15kv with a nominal temperature of 3500c. Examples are high voltage power supplies radar x rays and laser. Values from 1w up to 10 m w are available.

Many production amps lower cost tube amps have carbon film resistors because they are cheaper than other types saving the builder a few bucks per unit. A carbon pile resistor is made of a stack of carbon disks compressed between two metal contact plates. This carbon film restricts the flow and hence is the imperative part of this resistor.

The carbon film resistors are constructed or manufactured using a deposition process. Resistors like this are much cheaper to make and are called carbon film. What is a carbon film resistor the carbon film resistor is formed using a ceramic carrier rod onto which a thin layer of pure carbon is deposited as a film.

Carbon film resistors are made with a deposition process. Inside a wire wound resistor. It is the thin carbon film that acts as the resistive element.

Carbon resistor construction. Typical use for carbon film resistors is in high voltage and temperature applications. This increases the resistance value and is also a way to control the resistance value more precise.

Carbon film resistor applications. Generally wire wound resistors are more precise and more stable at higher operating temperatures. In smaller value resistors designed for lower power circuits the copper winding is replaced by a spiral pattern of carbon.

As mentioned earlier a carbon film is deposited on a ceramic substrate. It is due to this reason the resistor is named carbon film resistor. The generic term film resistor consist of metal film carbon film and metal oxide film resistor types which are generally made by depositing pure metals such as nickel or an oxide film such as tin oxide onto an insulating ceramic rod or substrate.

Boutique makers often use the older carbon comp types to exploit unknowing buyers out of a lack or education pure mysticism or a desire for the inside of their amps to look old timey. The carbon powder acts as the good conductor of electric current. These resistors are used when an adjustable load is required for example in testing automotive batteries or radio transmitters.

To enable the carbon film resistor to have the correct resistance a helical cut is normally made into the film. The cylindrical resistive element of the carbon composition resistor is made from the mixture of carbon or graphite powder and ceramic made of clay.