Solenoids are also used instead of hammers where moveable mass is fixed http://algo.mur.at/projects/powerflowerbells/media/powerbells_1/powerbell_with_solenoid.jpg/view http://algo.mur.at/projects/powerflowerbells/media/powerbells_1/powerbell_with_solenoid.jpg/@@download/image/relais.jpg

Solenoids are also used instead of hammers