Kommutator (elektrisk)

For alternative betydninger, se Kommutator. (Se også artikler, som begynder med Kommutator)
En elektromotor fra en støvsuger. Kommutatoren ses til venstre.

En mekanisk kommutator er en vinkelafhængig elektrisk omskifter, som sidder på rotoren af elektromotorer til jævnspænding og som formidler den elektriske kontakt via fjederbelastet kul eller metal, som sidder på statoren. Kommutatoren fungerer som en variabel frekvens vekselretter.[1][2]

En del nyere elektromotorer har elektronisk kommutering de kaldes også børsteløse DC-motorer. Fordelen ved de børsteløse elmotorer er mindre vedligeholdelse, højere startdrejningsmoment, variabel hastighed, færre udgifter og mindre elektrisk støj.[3][4] Elektronisk kommutering kan fx anvende Hall sensorer, som registrerer magnetfeltsveksling og de anvendes til at styre transistorer eller andre halvlederkomponenter.[5]

Se også

Referencer

  1. ^ Fundamental Concepts: Motors: Commutator Citat: "...The commutator on the DC generator converts the AC into pulsating DC...By mechanically positioning the brushes on the commutator, an angle of displacement can be set up between the magnetic force of the field windings and the magnetic force of the rotor windings...", backup
  2. ^ HyperPhysics, Physics and Astronomy, Georgia State University: Commutator and Brushes on DC Motor
  3. ^ industrial-electronics.com: The non-classic motors: Electronic commutation for the DC brushless motor Arkiveret 9. september 2021 hos Wayback Machine Citat: "... In a way, this machine can be viewed as a dc motor in which electronic commutation replaces the commutator and brushes. The mere fact that the commutator-brush assemblage is dispensed with, implies low maintenance, low RFI and EMI, and low cost...For example, such features as high starting torque and variable speed can now easily be realized together..."
  4. ^ sciencedirect.com: Electronic Commutator Direct Current (ECDC) machine Citat: "...Today new technology is attempting to replace these components and reduce permanently these maintenance costs. When the task of commutator and brushes are replaced by solid-state switches, free maintenance motors are invented and the new motor called brushless DC motors emerged..."
  5. ^ July 2000, fab.cba.mit.edu: Electronic commutation Citat: "...The stator, on the other hand, consists of a three-phase, Y-connected winding and three Hall-effect sensors. The sensor magnet turns the Hall-effect sensors “on” and “off,” indicating the position of the shaft. With this information, the controller is able to switch current to each winding at the optimum timing point...", backup

Eksterne henvisninger

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Motors01CJC.jpg
Forfatter/Opretter: en:User:C_J_Cowie, Licens: CC BY-SA 3.0
Some samples of electric motor sizes.

Common Nine-volt battery in the middle front
Largest motor:
Three phase AC induction motor rated with 1 Hp (750 W)
Next largest: 25 W

Small motors: CD player motor, Brushed DC Electric Motor common as toy motors, Stepper motor with worm gear for CD pickup-head traversing
Kommutator universalmotor stab.jpg
Forfatter/Opretter: Sebastian Stabinger Paethon, Licens: CC BY-SA 3.0
Rotor from a universal motor from a vacuum cleaner. (Anker eines Universalmotors aus einem Staubsauger. Wicklungen etc. wurden von Hand neu gemacht.)