866A – 15 kV AC – 2D computer graphics – 3Com – Abrasion (mechanical) – AC adapter – AC power plugs and sockets – AC power – AC/AC converter – AC/DC receiver design – AC/DC conversion – Active rectification – Actuator – Adaptive control – Adjustable-speed drive – Advanced Z-transform – Affinity law – Agbioeletric – AIEE – All American Five – Alloy – ALOHAnet – Alpha–beta transformation – Altair 8800 – Alternating current – Alternator (auto) – Alternator synchronization-- Alternator – Altitude – Aluminium smelting – AIEE – Ammeter – Amorphous metal transformer – Ampacity – Ampere – Ampère's circuital law – Ampère's force law – Ampère's law – Amplidyne – Amplifier – Amplitude modulation – Analog circuit – Analog filter – Analog signal processing – Analog signal – Analog-to-digital converter – Annealing (metallurgy) – Anode – Antenna (radio) – Apollo program – Apparent power – Apple Computer – Arc converter – Arc furnace – Arc lamp – Arc welder – Argon – Arithmetic mean – Armature (electrical engineering) – Artificial heart – Artificial intelligence – Artificial neural networks – Artificial pacemaker – ASTM – Asymptotic stability – Asynchronous circuit – Audio and video connector – Audio equipment – Audio filter – Audio frequency – Audio noise reduction – Audio signal processing – Audion tube – Austin transformer – Automatic gain control – Automatic transfer switch – Automation – Autorecloser – Autotransformer – Availability factor – Avalanche diode – Average rectified value –