MFEM - created from Mind Map

Seite 1

HAND RULES

POWER GENERATION

MAGNETIC FIELDS

ELECTROMAGNETIC INDUCTION

ELECTROMAGNETIC EFFECT

GRIP

SLAP

SCREW

INDUCED CURRENT

CONVENTIONS

Fingers = CURRENT

Thumb = NORTH

solenoid or loop

Thumb = CURRENT

Palm = FORCE

Fingers = MAG. FIELD

Only if at 90 degrees

Current Carrying Conductor

Thumb = CURRENT

Fingers = DIRECTION OF MAG. FIELD

straight

Thumb = MOTION

1st finger = MAG. FIELD

2nd finger = CURRENT

X = INTO

O = OUT

Powerstation

RMS Voltage

70% of peak of graph

240V in Aust.

Produced By

Rules

James Clark Marshall

Spinning electrons

Domains

Electric & Mag. field at 90 degrees

Produces Current

North to South

Null Field

Don't Cross

3D

90 degrees

Temp. Domains

Perm Domains

Mag. Hard

Mag. Soft

Left Hand Rule

Faraday's Law

Lenz's Law

Transformers

Force on electrons

Generators

EMF

Max. occurs every 0.25 complete rotation

Flux = no. field lines

Rotating Coils

Induced I opposes any change

Eddy Currents

Electrons moving in response to mag. field

Beneficial

Harmful

Produce own mag. field

Braking

Heating

Produce force that opposes movt.

Produce heat conducted

Heat increase R => increase P loss

Decrease P available

Iron Core

Step Up

Step Down

Increase eddy currents

Increase Mag. Field

Min. by laminations

Decrease Heat & P loss

Increase EMF

N secondary > N primary

N secondary

P total constant

MOTOR EFFECT

Equations

Generators vs. Motors

Brushes

Pivotal Force

Allows current flow

TORQUE = NET TURNING FORCE

Ohm's Law

Circuit Theory

Force

V=RI

Parallel

Series

AC

DC