Magnets Course

Lesson 1 • Magnetic Field Lines and Flux

Describes how magnetic field lines represent field direction and strength. Introduces magnetic flux as a quantitative measure of field through a surface.

Lesson 2 • Units and Measurement Basics

Introduces SI units for magnetic quantities including tesla, gauss, and ampere per metre. Provides the numerical literacy needed for all subsequent quantitative work.

Lesson 3 • Magnetic Domains and Alignment

Introduces magnetic domains as regions of aligned dipoles within materials. Explains how domain alignment produces or destroys net magnetisation.

Lesson 4 • Atomic Origins of Magnetism

Explains how electron spin and orbital motion generate magnetic moments. Connects atomic-level behaviour to observable bulk magnetism.

Lesson 1 • Soft vs. Hard Magnetic Materials

Contrasts easily magnetised soft materials with high-coercivity hard materials. Guides material selection decisions for motors, sensors, and permanent magnets.

Lesson 2 • Paramagnetic Materials

Explains weak attraction arising from partial alignment of permanent dipoles. Connects temperature dependence to the Curie law introduced here.

Lesson 3 • Ferromagnetic Materials

Details strong spontaneous magnetisation from exchange interaction and domain alignment. This is the most commercially significant magnetic class covered in the course.

Lesson 4 • Ferrimagnetic and Antiferromagnetic Materials

Distinguishes partial cancellation in ferrimagnets from full cancellation in antiferromagnets. Highlights ferrite applications relevant to electronics and data storage.

Lesson 1 • Magnetisation and Demagnetisation Processes

Describes impulse magnetisation, saturation requirements, and controlled demagnetisation techniques. Students can specify magnetising fixtures and demagnetising procedures.

Lesson 2 • Magnet Geometry and Permeance

Relates magnet shape and aspect ratio to the operating point on the demagnetisation curve. Proper geometry selection maximises flux delivery to the air gap.

Lesson 3 • The Hysteresis Loop in Depth

Examines the B-H curve to extract remanence, coercivity, and energy product. These parameters are the primary design metrics for permanent magnets.

Lesson 4 • Common Permanent Magnet Families

Surveys alnico, ferrite, samarium-cobalt, and neodymium-iron-boron magnet families. Compares performance, cost, and temperature stability across families.

Lesson 1 • Magnetic Circuit Analogy

Maps MMF, reluctance, and flux to voltage, resistance, and current in electric circuits. Enables systematic analysis of complex flux paths using familiar circuit tools.

Lesson 2 • Coil Design and Winding Parameters

Guides selection of wire gauge, turn count, and winding geometry to meet field and thermal requirements. Balances resistance, inductance, and heat dissipation.

Lesson 3 • Core Materials and Losses

Evaluates silicon steel, amorphous alloys, and powder cores for AC electromagnet cores. Quantifies hysteresis and eddy-current losses that reduce efficiency.

Lesson 4 • Electromagnetism Fundamentals

Connects electric current to magnetic field generation via Ampere's law. Establishes the quantitative link between current, turns, and magnetomotive force.

Lesson 1 • Energy Methods for Force Calculation

Uses co-energy and virtual work principles to find forces without stress tensors. Provides an alternative approach validated against Maxwell stress results.

Lesson 2 • Lorentz Force on Moving Charges

Derives the force on a charged particle moving through a magnetic field. Provides the physical basis for motors, particle accelerators, and Hall sensors.

Lesson 3 • Magnetic Pressure and Maxwell Stress

Introduces Maxwell stress tensor to compute surface forces on magnetic materials. Enables accurate force prediction in actuators and magnetic clamping systems.

Lesson 4 • Magnetic Bearings and Levitation

Applies force principles to passive and active magnetic bearing designs. Covers stability criteria, load capacity, and control requirements for levitation.

Lesson 1 • Transformer Design and Core Selection

Guides core material selection, area product method, and winding layout for a target design. Integrates magnetic circuit analysis with thermal and insulation constraints.

Lesson 2 • Faraday's and Lenz's Laws

States and applies the laws governing induced EMF from changing flux. Lenz's law provides the direction rule essential for all inductive device analysis.

Lesson 3 • Ideal Transformer Analysis

Derives voltage, current, and impedance transformation ratios for an ideal transformer. Provides the reference model against which real transformer losses are measured.

Lesson 4 • Real Transformer Losses and Efficiency

Accounts for copper losses, core losses, and leakage inductance in real transformers. Students calculate efficiency and regulation under load conditions.

Lesson 1 • Gaussmeters and Teslameters

Covers handheld and benchtop instruments for point-field measurement in industrial settings. Addresses probe selection, zeroing, and environmental interference.

Lesson 2 • Magnetic Field Mapping Techniques

Combines multiple sensors and scanning stages to produce 2D and 3D field maps. Supports quality control and design validation of magnetic assemblies.

Lesson 3 • Fluxmeters and Search Coils

Uses Faraday's law to measure flux change with search coils and fluxmeters. Suitable for characterising permanent magnets and transformer cores.

Lesson 4 • Hall Effect Sensors

Explains the Hall effect and its use in measuring DC and AC magnetic fields. Covers sensor selection, placement, and signal conditioning for accurate readings.

Lesson 1 • Magnetic Data Storage Principles

Explains how bits are written and read using magnetic coercivity and magnetoresistance. Connects material properties from earlier chapters to recording media design.

Lesson 2 • Magnetic Sensors in Industrial Systems

Surveys magnetoresistive, fluxgate, and SQUID sensors for precision industrial measurement. Compares sensitivity, bandwidth, and noise floor across sensor technologies.

Lesson 3 • System-Level Magnetic Design Process

Presents a structured workflow from specification through simulation, prototyping, and validation. Students apply the full design process to a capstone magnetic system project.

Lesson 4 • Electric Motor Magnetic Design

Applies field, force, and material knowledge to brushless DC and induction motor design. Focuses on air gap flux density, slot geometry, and torque production.