Tutorial: Physics Topic: Alternator Prepared by: RNDr. Ondřej Jeřábek Projekt Anglicky v odborných předmětech, CZ.1.07/1.3.09/04.0002 je spolufinancován Evropským sociálním fondem a státním rozpočtem České republiky.
General information: Alternator is rotary electric machine Changes rotary energy ( kinetics energy ) or mechanical energy to electric energy Output capacity is led to electrical system
Alternator works on electrical induction principle Voltage is induced in conductor, if conductor and magnetic field move to each other Extent of induced voltage depends on magnetic field rate and conductor movement speed ( engine revolutions )
Alternators are synchronous machines According to their rotor’s type they further divide to: With plain rotor- turbo-alternators – driving machine is mostly steam turbine (in steam power plant) speed turns 3000 min -1, as network freqeuency 50 Hz Low-acting alternators are driven by low-acting machine (mostly by water turbine). Speed turn is whole number ratio of 3000 min -1, as network frequency 50 Hz It makes mechanically connected set with driving machine. Driving machine and alternator are on the same shaft.
Alternator with rectifier is designed so that accumulator is charged when combustion engine runs idle It is important advantage for city traffic Accumulator durability charged by alternator with rectifier is longer than accumulator durability charged by dynamo Alternator is excited directly of accumulator immediately after ignition start
Alternators produce electricity in the same way as direct-current generators Rotating magnet rotates – rotor inside stationary fit windings on iron cores - stator Electrical current is produced by rotor movement caused by mechanic energy There are mostly sets of stator windings in stator that are moved round slight amount of 180° Rotor magnetic field can be caused by induction or permanent magnet
Car alternator has the same construction as industrial alternators Car alternator produces 3- phase electrical current Alternating current must be rectified before entry to car network Diodes are used to rectifying of alternating current Diodes are fixed to diode bridge To limitation of voltage values, alternator output direct current is controlled by Zener diode Alternator advantage comparing with dynamo is mainly its low weight
Find out alternator on the Internet: a) Alternator´s rotor and stator b) Find out on the Internet alternator wiring diagram wired to electrical circuit
Describe main alternator components that you found out on the Internet Describe and explain alternator wiring to electrical circuit
JAN, Zdeněk; ŽDÁNSKÝ, Bronislav ; ČUPERA, Jiří. Automobily 1. Brno : Avid, 2004. 211 s. JAN, Zdeněk; ŽDÁNSKÝ, Bronislav ; ČUPERA, Jiří. Automobily 2. Brno : Avid, 2004. 120 s. JAN, Zdeněk; ŽDÁNSKÝ, Bronislav ; ČUPERA, Jiří. Automobily 3. Brno : Avid, 2004. 220 s. JAN, Zdeněk; ŽDÁNSKÝ, Bronislav ; ČUPERA, Jiří. Automobily 4. Brno : Avid, 2004. 350 s. Translation: www.seznam.cz www.seznam.cz www.slovnik.cz www.slovnik.cz JANATA, Petr. Handy slovník technický anglicko-český a česko-anglický. Plzeň: Nakladatelství Fraus, 2000. ISBN 80-7238-075-3 Lingea LEXIKON 5, Technický slovník anglicko-český a česko-anglický. 2010.