Glossary of Terms

AC Alternating Current, an electrical system where voltage oscillates in a sine wave.
Battery An energy storage device based on chemical reactions. Used as the power source for electric vehicles.
BLDC BrushLess Direct Current, refers to a type of motor which has no commutator or brushes, instead having its magnetic field rotated via electronic switching.
Circuit Breaker An electronic device designed to switch off automatically when current flow through the device exceeds a threshold. Used as a resettable fuse for safety.
Commutator The part of a brush motor's rotor which controls transmission of power into the rotor coils to maintain magnetic field rotation.
DC Direct Current, referring to a type of electrical flow where current flows continuously in one direction.
Direct Drive Describes a drivetrain with no gearbox, where the motor drives the vehicle's differential directly. This is possible thanks to the huge torque available from electric motors, and the simplicity of this solution makes it a popular choice for rear wheel drive vehicles. (It is harder to achieve in vehicles with a transaxle.)
EV Electric Vehicle, any vehicle which uses electric motors as its sole means of propulsion.
HEV Hybrid Electric Vehicle, any type of vehicle which uses an electric motor as a supplement to it's prime mover (usually a petrol engine).
ICE Internal Combustion Engine, a type of machine which converts fuel and air into mechanical motion by burning it in an enclosed space. Sometimes called Infernal Combustion Engine.
IGBT Insulated Gate Bipolar Transistor, a type of semiconductor transistor designed for high power amplifiers.
Lead Acid An old type of rechargeable battery commonly used in older electric vehicles and as auxilliary batteries in ICE vehicles.
LFP LiFePO4, or Lithium Iron Phosphate, a type of lithium ion battery technology boasting very long lifespans and (relatively) robust operating range.
Lithium Ion A type of battery which uses lithium ions as the charge carrier. Very high power density, though relatively expensive.
Lithium Polymer A newer type of lithium ion battery, offering the highest power densities though at the expense of robustness. (Not very tolerance of overcharging or overtemperature conditions.)
MOSFET Metal Oxide Semiconductor Field Effect Transistor, the most common type of transistor used in modern amplifiers and motor speed controllers.
PHEV Plug-in Hybrid Electric Vehicle, a type of hybrid vehicle which has the option of having its batteries recharged from an external source (such as mains power). Usually they have a larger battery enabling ~50km range on electric drive alone.
PWM Pulse Width Modulation, a high-efficiency technique for controlling voltage output in a motor controller or voltage converter.
Regen Abbreviation for Regenerative Braking, a system where the electric drive motor is used as a generator to recover kinetic energy from the vehicle while slowing it down.
Rotor The part of an electric motor which rotates (connected to the drive shaft).
Sepex Abbreviation for Separately Excited, referring to the way in which a DC motor's field coils are energised. In a Sepex motor, they require a separate power source.
Shunt 1) A very low value, high power resistor used as a reference for current measurement. Using ohms law, the voltage drop across the known resistance is proportional to the current flowing. 2) A format of DC motor, referring to the field coils being connected in parallel with the rotor coils.
Stator The part of an electric motor which does not rotate, usually referring to the field coils.
Transaxle Most front wheel drive vehicles have a gearbox and differential combined into a modular unit, which is known as a transaxle.