Position responsive switch for electrical appts. - using non-metallic, electrically-conducting liquid for bridging spaced electrodes in switched tube

摘要

The switch has a float housing (10) containing a switch tube (2) which is partly filled with an electrically-conducting liquid (24) providing a conduction path between two spaced electrodes (22,23) in dependence on the position. The electrically-conducting liquid (24) is non-metallic, e.g. water and the electrodes (22,23) are coupled to an associated electronic circuit which maintains the voltage across them at below the decomposition voltage for the electrically-conducting liquid (24) and which amplifies the switch current. The switch is coupled to the controlled electrical appts. via a 2-wire electrical cable (4). ADVANTAGE -Reduced weight and switch hysteresis.