6mm potentiometer Brush, Sliding Q and Central Contact Ring            

The dynamic contact component of the potentiometer which slides along the resistor body and leads out the input voltage is called brush < or contact brush, which can be divided into two categories: one is metal brush. That is, brushes made of metal materials; the other is carbon brushes, that is, brushes made of carbon morning I drowning and tree fingers and other mixed materials. Metal brushes have brush shape, point shape, spherical shape and'multi-finger'shape. Multi-finger brush is the best way to ensure contact reliability and uniform current distribution. The shape of carbon brush is conical and rectangular, the contact surface is flat and spherical, the contact reliability, low noise, mechanical durability and service life of potentiometer are directly related to the contact state and mechanical wear of brush-resistor. Therefore, the brush material should have the characteristics of corrosion resistance, oxidation resistance, heat resistance, cold resistance, good thermal conductivity, good electrical conductivity, no magnetism, low contact resistance, high wear resistance and good mechanical strength. Brushes and resistors are always in contact and friction state. The two materials should be matched and combined properly to obtain low contact resistance and good wear resistance. If the combination is not correct, one of them may wear out quickly. Compared with the resistor, the hardness and wear resistance of the brush should be slightly lower so as to protect the resistor from damage and ensure its reliability. When choosing carbon brush, the resistance of carbon brush is much greater than that of metal brush, so it has a great influence on the output of potentiometer. The resistance value of carbon brush is lower than the content of carbon black and graphite in the formula. High carbon content, low resistance, but poor strength. For high-demand carbon brushes, metal powder (such as silver powder) is sometimes added to reduce resistance. The smaller the resistance of carbon brushes, the better, generally no more than 6 ohms. The strength of the carbon brush is the maximum pressure that the carbon brush can withstand. High strength can withstand high pressure, so the contact resistance with the resistor is small.            

1. 6mm potentiometer Brushes made of metal materials should have higher tensile strength and elongation, and be easy to weld and assemble. Metal brushes should be made of metal materials with good elasticity, so that the contact of the brush can exert a certain elastic pressure on the resistor. Elastic materials should have high elastic limit and yield limit. In the long-term use, the smaller the change of elastic pressure of the brush, the higher the contact reliability. Commonly used materials for metal brushes are beryllium bronze, phosphor bronze, zinc bronze, silver-chromium alloy, platinum-nickel alloy, platinum-iridium alloy, pound-iridium alloy, gold-silver-copper alloy, etc. The alloys based on precious metals have high oxidation and corrosion resistance, even at high temperature and humidity. They are stable and have little change in contact resistance. They are often used in precision potentiometers.‘            

2. 6mm potentiometer Sliding arm (or slider) the sliding arm is a component connecting the rotating shaft (or sliding handle) and the brush. It uses the moving rotating shaft brush of the rotating shaft (or sliding handle) to drive the brush to slide the sliding arm material of the sliding body on the resistor. According to the structure of the potentiometer, metal or non-metal materials are selected. If elastic metal material is selected, the sliding arm will exert elastic pressure on the brush; if rigid material is used, the brush should be elastic, or elastic parts are used to exert elastic pressure on the brush. Commonly used as sliding arm materials are cloth limb pivot, paperboard, plastic family, brass, silver copper and phosphorus bronze, etc. Metal materials generally need to be plated with protective coatings.            

3.6mm potentiometer Contact reed the contact reed is a groove connecting the brush and the collector. It transfers the electric output of the brush to the collector and leads out the rui. Contact reed is a kind of dynamic contact connection between contact reed and collector, so contact reed has great influence on mechanical durability, contact stability and dynamic noise of potentiometer. Therefore, contact reed should have good elasticity to ensure a certain elastic pressure on the collector; it also has good conductivity and thermal conductivity, and its hardness and wear resistance should match the collector. Commonly used materials are phosphorus bronze and quilt bronze. Contact reeds are often integrated with brushes or sliding arms.