Image: DoorBell 002

Description: This door bell is composed of: thin clear green line: solenoids thin pink line: bell thick dark green line: clapper thin blue line: spring that holds the clapper and that gives electrical contact think dark blue line: screw for adjusting the electrical contact oval thin red line: contact-area of opening contact Function: Without current applied the bell is as shown in the photograph. The clapper is with some distance to the bell. The electrical contact is closed. When you apply current, the solenoids attract the clapper and the clapper strikes against the bell. The electrical contact opens. An electric arc starts between spring and contact-screw. The current decreases and the solenoids become too weak to keep the clapper in closed position. So the clapper swings back to initial position and closes the electrical contact again.
Title: DoorBell 002
Credit: Own work
Author: HNH
Permission: I, the copyright holder of this work, hereby publish it under the following licenses: This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license. You are free: to share – to copy, distribute and transmit the work to remix – to adapt the work Under the following conditions: attribution – You must attribute the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the work). share alike – If you alter, transform, or build upon this work, you may distribute the resulting work only under the same or similar license to this one. http://creativecommons.org/licenses/by-sa/3.0 CC BY-SA 3.0 Creative Commons Attribution-Share Alike 3.0 truetrue Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled GNU Free Documentation License.http://www.gnu.org/copyleft/fdl.htmlGFDLGNU Free Documentation Licensetruetrue You may select the license of your choice.
Usage Terms: Creative Commons Attribution-Share Alike 3.0
License: CC BY-SA 3.0
License Link: http://creativecommons.org/licenses/by-sa/3.0
Attribution Required?: Yes