Brush (electric)

A pair of carbon brushes

Electrical contact which conducts current between stationary wires and moving parts, most commonly in a rotating shaft.

- Brush (electric)
A pair of carbon brushes

41 related topics

Relevance

Commutator in a universal motor from a vacuum cleaner. Parts: (A) commutator, (B) brush, (C) rotor (armature) windings, (D) stator (field) windings, (E) brush guides, (F) electrical connections.

Commutator (electric)

Rotary electrical switch in certain types of electric motors and electrical generators that periodically reverses the current direction between the rotor and the external circuit.

Rotary electrical switch in certain types of electric motors and electrical generators that periodically reverses the current direction between the rotor and the external circuit.

Commutator in a universal motor from a vacuum cleaner. Parts: (A) commutator, (B) brush, (C) rotor (armature) windings, (D) stator (field) windings, (E) brush guides, (F) electrical connections.
400px
Cross-section of a commutator that can be disassembled for repair.
A tiny 5-segment commutator less than 2 mm in diameter, on a direct-current motor in a toy radio control ZipZaps car.
Various types of copper and carbon brushes.
Compound carbon brush holder, with individual clamps and tension adjustments for each block of carbon.
Different types of brushes have different brush contact angles
Commutator and brush assembly of a traction motor; the copper bars can be seen with lighter insulation strips between the bars. Each dark grey carbon brush has a short flexible copper jumper lead attached. Parts of the motor field winding, in red, can be seen to the right of the commutator.
Commutating plane definitions.
Centered position of the commutating plane if there were no field distortion effects.
Actual position of the commutating plane to compensate for field distortion.
Brush advance for Self-Induction.
Low voltage dynamo from late 1800s for electroplating. The resistance of the commutator contacts causes inefficiency in low voltage, high current machines like this, requiring a huge elaborate commutator. This machine generated 7 volts at 310 amps.

Two or more electrical contacts called "brushes" made of a soft conductive material like carbon press against the commutator, making sliding contact with successive segments of the commutator as it rotates.

Sketch of a cross-section of slip rings for an electric motor. In this example, the slip rings have a brush-lifting device and a sliding contact bar, allowing the slip-rings to be short-circuited when no longer required. This can be used in starting a slip-ring induction motor, for example.

Slip ring

Electromechanical device that allows the transmission of power and electrical signals from a stationary to a rotating structure.

Electromechanical device that allows the transmission of power and electrical signals from a stationary to a rotating structure.

Sketch of a cross-section of slip rings for an electric motor. In this example, the slip rings have a brush-lifting device and a sliding contact bar, allowing the slip-rings to be short-circuited when no longer required. This can be used in starting a slip-ring induction motor, for example.
Slip rings on a hydroelectric generator; 
A - stationary spring-loaded graphite brushes, 
B - rotating steel contact ring, 
C - insulated connections to generator field winding, 
D - top end of generator shaft.

Either the brushes or the rings are stationary and the other component rotates.

Animation showing operation of a brushed DC electric motor.

Electric motor

Electrical machine that converts electrical energy into mechanical energy.

Electrical machine that converts electrical energy into mechanical energy.

Animation showing operation of a brushed DC electric motor.
Cutaway view through stator of induction motor.
Faraday's electromagnetic experiment, 1821
Jedlik's "electromagnetic self-rotor", 1827 (Museum of Applied Arts, Budapest). The historic motor still works perfectly today.
An electric motor presented to Kelvin by James Joule in 1842, Hunterian Museum, Glasgow
Electric motor rotor (left) and stator (right)
Salient-pole rotor
Commutator in a universal motor from a vacuum cleaner. Parts: (A) commutator, (B) brush
Workings of a brushed electric motor with a two-pole rotor and PM stator. ("N" and "S" designate polarities on the inside faces of the magnets; the outside faces have opposite polarities.)
A: shunt B: series C: compound f = field coil
6/4 pole switched reluctance motor
Modern low-cost universal motor, from a vacuum cleaner. Field windings are dark copper-colored, toward the back, on both sides. The rotor's laminated core is gray metallic, with dark slots for winding the coils. The commutator (partly hidden) has become dark from use; it is toward the front. The large brown molded-plastic piece in the foreground supports the brush guides and brushes (both sides), as well as the front motor bearing.
Large 4,500 hp AC induction motor.
A miniature coreless motor
A stepper motor with a soft iron rotor, with active windings shown. In 'A' the active windings tend to hold the rotor in position. In 'B' a different set of windings are carrying a current, which generates torque and rotation.

Two or more electrical contacts called "brushes" made of a soft conductive material like carbon press against the commutator.

Free-body diagram of a U-channel synchronous linear motor. The view is perpendicular to the channel axis. The two coils at centre are mechanically connected, and are energized in "quadrature" (meaning a phase difference of 90° (π/2 radians) between the flux of the magnets and the flux of the coils). The bottom and upper coils in this particular case have a phase difference of 90°, making this a two phase motor. (Not to scale)

Linear motor

Electric motor that has had its stator and rotor "unrolled", thus, instead of producing a torque , it produces a linear force along its length.

Electric motor that has had its stator and rotor "unrolled", thus, instead of producing a torque , it produces a linear force along its length.

Free-body diagram of a U-channel synchronous linear motor. The view is perpendicular to the channel axis. The two coils at centre are mechanically connected, and are energized in "quadrature" (meaning a phase difference of 90° (π/2 radians) between the flux of the magnets and the flux of the coils). The bottom and upper coils in this particular case have a phase difference of 90°, making this a two phase motor. (Not to scale)
Synchronous linear motors are straightened versions of permanent magnet rotor motors
A typical 3 phase linear induction motor. An aluminium plate on top often forms the secondary "rotor".
Railgun schematic
Piezoelectric motor action
This Line 6 Guangzhou Metro train manufactured by CRRC Sifang and Kawasaki Heavy Industries propels itself using an aluminium induction strip placed between the rails.
A linear motor for trains running Toei Ōedo Line
Close-up of the flat passive conductor surface of a motion control 
Sawyer motor
The Birmingham International Maglev shuttle

Brush (electric) linear motors were used in industrial automation applications prior to the invention of Brushless linear motors.

Cleaning brushes

Brush

Common tool with bristles, wire or other filaments.

Common tool with bristles, wire or other filaments.

Cleaning brushes
Assortment of cleaning brushes, including bottle brushes
A clothes brush
Assorted cosmetics and Make-up brushes
A toilet brush

Brush (electric), used on electrical motors

Electric chair at the Florida State Prison

Electric chair

Electric chair, is a method of execution originating in the United States in which the condemned person is strapped to a specially built wooden chair and electrocuted through electrodes fastened on the head and leg.

Electric chair, is a method of execution originating in the United States in which the condemned person is strapped to a specially built wooden chair and electrocuted through electrodes fastened on the head and leg.

Electric chair at the Florida State Prison
A June 30, 1888, Scientific American illustration of what the electric chair suggested by the Gerry Commission might look like.
Harold Brown demonstrating the killing power of AC to the New York Medico-Legal Society by electrocuting a horse at Thomas Edison's West Orange laboratory.
The execution of William Kemmler, August 6, 1890
The former Louisiana execution chamber at the Red Hat Cell Block in the Louisiana State Penitentiary, West Feliciana Parish. The electric chair is a replica of the original.

That evening a drunken dock worker named George Lemuel Smith, looking for the thrill of a tingling sensation he had noticed when grabbing the guard rail in a Brush Electric Company arc lighting power house, managed to sneak his way back into the plant at night and grabbed the brush and ground of a large electric dynamo.

Diagram of a spark transmitter

Television interference

Particular case of electromagnetic interference which affects television reception.

Particular case of electromagnetic interference which affects television reception.

Diagram of a spark transmitter
A typical SCR based light dimmer which dims the light through phase angle control. This unit is wired in series with the load. Diodes (D2, D3, D4 and D5) for a bridge which generates DC with much ripple. R and C form a circuit with a time constant, as the voltage increases from zero (at the start of every halfwave) C will charge up, when C is able to make ZD conduct and inject current into the SCR the SCR will fire. When the SCR conducts then D1 will discharge C via the SCR. The SCR will shut off when the current falls to zero when the supply voltage drops at the end of the half cycle, ready for the circuit to start work on the next half cycle.

Electric motors that have a commutator can suffer from sparking at the brushes.

Two familiar allotropes of carbon: graphite and diamond.

Allotropes of carbon

Capable of forming many allotropes due to its valency.

Capable of forming many allotropes due to its valency.

Two familiar allotropes of carbon: graphite and diamond.
Eight allotropes of carbon:
(a) diamond,
(b) graphite,
(c) lonsdaleite,
(d) C60 buckminsterfullerene,
(e) C540 fullerite
(f) C70 fullerene,
(g) amorphous carbon,
(h) zig-zag single-walled carbon nanotube.
Missing: cyclocarbon, carbon nanobuds, schwarzites, glassy carbon, and linear acetylenic carbon (carbyne)
Computer models of stable nanobud structures
A large sample of glassy carbon.
The K4 crystal
Diamond and graphite are two allotropes of carbon: pure forms of the same element that differ in structure.

In its pure glassy (isotropic) synthetic forms, pyrolytic graphite and carbon fiber graphite are extremely strong, heat-resistant (to 3000 °C) materials, used in reentry shields for missile nosecones, solid rocket engines, high temperature reactors, brake shoes and electric motor brushes.

Scottish inventions and discoveries

[[File:Maxwell'sEquations.svg|thumb|right|""the most significant event of the 19th century will be judged as Maxwell's discovery of the laws of electrodynamics""

[[File:Maxwell'sEquations.svg|thumb|right|""the most significant event of the 19th century will be judged as Maxwell's discovery of the laws of electrodynamics""

Carbon brushes for dynamos: George Forbes (1849–1936)

This image shows three single coil pickups on a Stratocaster guitar. Left to right: bridge, middle and neck pickups.

Single coil guitar pickup

Type of magnetic transducer, or pickup, for the electric guitar and the electric bass.

Type of magnetic transducer, or pickup, for the electric guitar and the electric bass.

This image shows three single coil pickups on a Stratocaster guitar. Left to right: bridge, middle and neck pickups.
String effect on a single coil (electric guitar). The coil is connected to a multimeter that indicates the voltage changes when the string moves. This signal is normally sent to an amplifier.
Sketch of Rickenbacker "frying pan" lap steel guitar from 1934 patent application
Gibson P-90 soap bar
P90 dog ear
Two pickups on a Telecaster
Stratocaster pickups, viewed along the neck profile. Note that the poles are of different heights.
"Lipstick"-style single coil pickups on a Danelectro guitar

The brush makes and breaks electrical contact with the commutator segment several thousand times a second at variable frequency dependent on load thus causing radio frequency noise.