What exactly is a carbon brush and what does it do?

You will find that when you buy a power tool, some products will send two small accessories in the box. Some people know it is a carbon brush, and some people neither know what it is called nor how to use it.

But now whether it is posters or sales introductions, electric tools are brushless motors as a major selling point. If you ask what is the difference, many people only know that the difference is whether there is a carbon brush or not. So what exactly is a carbon brush? What is the function, and what is the difference between a brushed motor and a brushless motor?

The main component of the carbon brush is carbon. When working, it is pressed by a spring to work on the rotating part like a brush, so it is called a carbon brush. The main material is graphite. Carbon brushes are also called electric brushes, which are widely used in electrical equipment. They are used to transmit signals or energy between the fixed part and the rotating part of some motors or generators. The shape is rectangular, and the metal wire is installed in the spring. , The carbon brush is a kind of sliding contact, so it is easy to wear and needs to be replaced regularly and the carbon deposits that have been worn out must be cleaned.

Carbon brushes are generally used on DC electrical appliances, such as refrigerators, washing machines and air conditioners used in our homes, do not have brushes. This is because AC motors do not require a constant magnetic field, so there is no need for a commutator, and no carbon brushes.