Electric soap dispenser with automatic soap delivery - utilises change in electric or acoustic field caused by approach of hands

摘要

The switch mechanism works on the basis of one electrode being stored in the apparatus whilst the other electrode is formed by the hand located at earth potential. As the hand approaches the sensitive part of an oscillation circuit the timer is started which actuates the soap pump for a preset time. The start of the timer also starts a second timer which as the timer is switched off prevents a restart for several seconds. This avoids any undue delivery of soap or misuse. The switch mechanism only responds to the rapid movement of a hand in an electric or acoustic field and not to very slow movements such as condensation.