NE555

http://lecafedugeek.fr/le-ne555-ce-petit-circuit-integre-indispensable/

http://www.ptitrain.com/electronique/meccano/pages2002/bst555.htm

http://www.instructables.com/id/555-Timer/step8/555-Timer-Bistable-Mode-Circuit/

http://sam.electroastro.pagesperso-orange.fr/dossiers/555/555.htm

http://www.doctronics.co.uk/down555.htm

http://www.ohmslawcalculator.com/555_astable.php

http://web.udl.es/usuaris/p7806757/555-calculadora/555%20Calculator.htm

https://www.google.fr/search?q=555+online+calculator&oq=555+online+calculator&aqs=chrome..69i57.7012j0j7&sourceid=chrome&es_sm=93&ie=UTF-8