Editing Pencil sharpener (section)

==Electric sharpeners==
[[File:ELM V6 electric pencil sharpener.jpg|thumb|right|A well-used modern desk-style electric pencil sharpener]]
The oldest surviving electric pencil sharpener is the Boston Polar Club pencil sharpener, introduced around 1936.<ref>{{Cite web|url=https://www.antikeychop.com/bostonpolarclubpencilsharpener|title=The Antikey Chop|website=Boston Polar Club Pencil Sharpener|access-date=2019-08-28}}</ref> Electric pencil sharpeners work on the same principle as manual ones, but one or more flat-bladed or cylindrical cutters are rotated by an [[electric motor]].<ref name="officemuseumelectric">{{cite web|url=http://www.officemuseum.com/electric_sharpener_gallery.htm|title=Electric Pencil Sharpeners|access-date=9 July 2011}}</ref> Some electric pencil sharpeners are powered by [[battery (electricity)|batteries]] rather than being plugged into a building's electrical system, making them more portable.

Auto-stop electric pencil sharpeners are able to sense when the tip of the pencil is long enough, so they stop automatically. In basic automatic pencil sharpeners, the lead may become too long and break, and so users must be careful to supervise the operation.