Fixed and sliding electrical contacts

Carbon in electrical engineering

Figure 1 - Structure of hexagonal natural graphite

Figure 2 - Degree of graphitization P1 as a function of highest processing temperature ( H T T )

Figure 3 - Evolution of a graphitizable carbon during a specific heat treatment (rapid heating) [11]

Figure 4 - Properties of industrial carbons, graphites and perfect graphite

Figure 5 - Cold-measured properties, as a function of the highest processing temperature, of an agglomerated graphitizable carbon

Figure 6 - Evolution of the magnetoresistance of various more or less graphitized carbons as a function of the highest processing temperature H T T

Figure 7 - Properties of graphitized carbons at 3,000°C as a function of measurement temperature

Figure 8 - Manufacture of fine-grained industrial polygranular carbons and graphites: schematic diagram

Figure 9 - Electric arc

Figure 10 - Two examples of graphite atomic absorption furnaces

Figure 11 - Current-carrying capacity of welding coals as a function of diameter

Figure 12 - Examples of graphite electrodes for machining EDM molds (photos Le Carbone-Lorraine)

Figure 13 - Fixed non-inductive power resistors (photo Le Carbone-Lorraine)

Figure 14 - Furnace resistor (photo Le Carbone-Lorraine)

Figure 15 - Wire and rail scrapers (photos by Le Carbone-Lorraine)

Figure 16 - Switching principle

Figure 17 - Brush rubbing on a commutator: diagram

Figure 18 - Reactance voltage and current: variations

Figure 19 - Lines of brooms resting on a collector (photo Le Carbone-Lorraine)

Figure 20 - Broom positions

Figure 21 - Sandwich and composite brooms

Figure 22 - Mounting the brushes: recommended and unadvisable positions

Figure 23 - Brushes for electric motors (photo Le Carbone-Lorraine)

Figure 24 - Split broom for traction equipment (photo Le Carbone-Lorraine)

Figure 25 - Positioning the brushes on the neutral line

Figure 26 - Worn manifolds