Protective device for aquarium heater - insulates when dry and conducts when wet as result of soluble salt in textile

摘要

The protective device, for a heater in an aquarium, consists of two contacts each connected to one pole of the voltage supply and connected together by a porous material (26) that conducts when wet but not when dry. The material is textile soaked in a soluble salt. The housing has holes to allow moisture or liquid to enter. The advantage lies in the ability of the device to keep operating even if a poorly conducting liquid (e.g. pure water) finds its way inside.